Gonorrhea

Infectious Disease MONDO:0004277 Pathograph 37 Show in embeddings browser Bacterial Infection Sexually transmitted infection

Gonorrhea is a sexually transmitted infection caused by the Gram-negative diplococcus Neisseria gonorrhoeae, an obligate human pathogen with no environmental or animal reservoir. It colonizes the mucosal epithelium of the urethra, cervix, rectum, pharynx, and conjunctiva, and is frequently asymptomatic - particularly at rectal and pharyngeal sites - which sustains onward transmission. Ascending infection causes pelvic inflammatory disease and tubal infertility; haematogenous spread causes disseminated gonococcal infection; and perinatal transmission causes ophthalmia neonatorum. Two features dominate its pathophysiology. First, the organism varies its surface antigens continuously and subverts complement and phagocytic killing, so infection elicits no protective immunity and reinfection is the rule. Second, it has sequentially acquired resistance to every antimicrobial class deployed against it - sulfonamides, penicillins, tetracyclines, and fluoroquinolones - leaving ceftriaxone as the last reliably effective first-line agent. This is the mechanistic inverse of syphilis, which after eight decades has still never developed clinically significant penicillin resistance.

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15
Pathophys.
16
Phenotypes
2
Gaps
37
Pathograph
7
Genes
3
Medical Actions
3
Differentials
1
Models
2
References
1
Deep Research
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Classifications

Harrison's Part
INFECTIOUS DISEASES
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Discussions and Knowledge Gaps

2
How much of gonococcal pathogenesis established in the estradiol-treated mouse transfers to human infection, given that mice are naturally resistant and that several key gonococcal virulence factors engage human-specific receptors?
HUMAN MODEL MISMATCH OPEN gonorrhea_mouse_model_human_specificity
Attached to
pathophysiology#Opa-CEACAM Engagement and Epithelial Invasion pathophysiology#Anti-Phagocytic Survival Within Neutrophils
N. gonorrhoeae is an obligate human pathogen. Mice are naturally resistant to genital infection and must be treated with 17-beta-estradiol to be colonized at all. Several central virulence interactions curated in this entry are human-restricted - Opa binding to human CEACAM receptors, and iron acquisition from human transferrin and lactoferrin - so the surrogate host lacks the very receptors the mechanism depends on. Conclusions about colonization, immune evasion, and vaccine protection drawn from this model therefore carry an unusually large translational gap.
Proposed experiments
Human CEACAM-transgenic mouse challenge
exp_gonorrhea_humanized_ceacam_mouse
Compare colonization, neutrophil interaction, and vaccine protection between wild-type estradiol-treated mice and mice transgenic for human CEACAM receptors, to quantify how much of the observed phenotype depends on the human-specific receptor interaction absent from the standard model.
Show evidence (2 references)
PMID:2506350 SUPPORT Model Organism
"Mice of these strains, therefore, appear resistant to gonococcal infection of the genital tract."
The natural murine resistance is the root of the mismatch this discussion poses: the model must be hormonally manipulated before it will support infection at all.
PMID:21204865 SUPPORT Other
"Most immune interactions are mediated via binding to members of the carcinoembryonic antigen cell adhesion molecule (CEACAM) family."
Establishes CEACAM engagement as the dominant immune interaction, the human-specific receptor family the murine model lacks.
Which antigens mediate the cross-protection that meningococcal OMV vaccines confer against gonorrhea, and can that protection be improved on deliberately?
KNOWLEDGE GAP OPEN gonorrhea_omv_vaccine_mechanism
Attached to
pathophysiology#Absence of Protective Immunity and Reinfection
OMV meningococcal vaccines reduce gonorrhea incidence substantially, but the protection is partial and the responsible antigens are not definitively identified. Because the effect was discovered epidemiologically rather than designed, the mechanism is inferred from antigenic homology rather than demonstrated. Identifying the protective antigens would convert an incidental benefit into a rational vaccine target for an organism that has otherwise defeated every antimicrobial deployed against it.
Proposed experiments
Antigen deconvolution of OMV cross-protection
exp_gonorrhea_omv_antigen_deconvolution
Use post-vaccination human sera to identify gonococcal antigens recognized after 4CMenB vaccination, then test them individually and in combination for protection, to determine whether the cross-protective response can be reproduced by a defined subunit vaccine.
Show evidence (1 reference)
PMID:42259835 SUPPORT Model Organism
"Meningococcal vaccines MeNZB and 4CMenB (Bexsero), containing Neisseria meningitidis group B detergent-extracted outer membrane vesicles (dOMV), cross-protect against gonorrhoea with 31-59% effectiveness."
Establishes that cross-protection is real but partial and attributed to the dOMV fraction rather than to identified antigens, which is precisely the gap this discussion poses.
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Pathophysiology

15
Gonococcal Mucosal Attachment and Microcolony Formation
The gonococcus adheres to mucosal epithelium using type IV pili, which mediate initial long-range attachment and microcolony formation, with the porin PorB and the phase-variable outer membrane protein Opa providing additional adhesion. This is the trigger event of the pathograph.
epithelial cell CL:0000066 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves epithelial cell (CL:0000066). CL:0000066 is a cell type from the Cell Ontology.
cell adhesion GO:0007155 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased cell adhesion (GO:0007155). GO:0007155 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Opa-CEACAM Engagement and Epithelial Invasion Adherent organisms engage host receptors and invade the epithelium.
Asymptomatic infection Colonization can persist without provoking the neutrophilic immunopathology that produces symptoms, which is the usual outcome at rectal and pharyngeal sites.
Show evidence (2 references)
PMID:35489793 SUPPORT Other
"The gonococcus initially colonises and adheres to host mucosal surfaces utilising a type IV pilus that helps with microcolony formation."
Directly describes type IV pilus-mediated attachment and microcolony formation as the initiating step.
PMID:35489793 SUPPORT Other
"Other adhesion strategies include the porin, PorB, and the phase variable outer membrane protein Opa."
Names the additional adhesins this node carries.
Opa-CEACAM Engagement and Epithelial Invasion
Opa proteins bind CEACAM family receptors on epithelial cells, neutrophils, and lymphocytes, driving receptor-mediated invasion and transcytosis of the epithelial layer. CEACAM engagement is not obligatory - Opa-expressing gonococci can also adhere to and invade genital epithelial cells by a CEACAM-independent route - so this node models the dominant pathway rather than the only one.
epithelial cell CL:0000066 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves epithelial cell (CL:0000066). CL:0000066 is a cell type from the Cell Ontology.
symbiont entry into host GO:0044409 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased symbiont entry into host (GO:0044409). GO:0044409 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Neutrophil Influx and Immunopathological Tissue Damage Epithelial invasion provokes the acute inflammatory response that produces the clinical disease.
Ascending Genital Tract Infection and Tubal Damage Invasion of the endocervical epithelium permits upward spread to the upper genital tract.
Show evidence (2 references)
PMID:21204865 SUPPORT Other
"These Opa variants are able to bind to different receptors of the CEACAM family on epithelial cells, neutrophils, and T and B lymphocytes, influencing the innate and adaptive immune responses."
Establishes Opa-CEACAM binding across the cell types this node names. Evidence source is OTHER because the citation is a review.
PMID:11580753 SUPPORT In Vitro
"when CEACAM is expressed, Opa+ gonococci exploit it for the adherence to and invasion of these cells."
PARTIAL, and deliberately included as a qualifier rather than a support: it establishes that the CEACAM route is not obligatory, which is why this node is worded as the dominant pathway rather than the only one.
Pilin and Opa Antigenic and Phase Variation
Pilin undergoes high-frequency antigenic variation by recombination with silent pilS loci, and the Opa paralogs undergo phase variation by slipped-strand mispairing. The resulting within-host antigenic diversity keeps the adaptive response chasing a moving target. This is the direct mechanistic counterpart of TprK gene conversion in Treponema pallidum - the same evolutionary solution reached by an unrelated organism.
Downstream
Absence of Protective Immunity and Reinfection Continuous surface-antigen turnover prevents the development of protective immune memory.
Show evidence (1 reference)
PMID:21204865 SUPPORT Other
"These Opa variants are able to bind to different receptors of the CEACAM family on epithelial cells, neutrophils, and T and B lymphocytes, influencing the innate and adaptive immune responses."
PARTIAL: establishes the existence of multiple Opa variants engaging immune cells, the substrate on which phase variation acts, without describing the variation mechanism itself.
Lipooligosaccharide Sialylation and Complement Evasion
The gonococcus sialylates its lipooligosaccharide using host-derived CMP-N-acetylneuraminic acid, masking the molecule and blocking complement activation and opsonophagocytic killing. This serum resistance is what permits survival in the bloodstream during dissemination.
complement activation GO:0006956 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased complement activation (GO:0006956). GO:0006956 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
Anti-Phagocytic Survival Within Neutrophils Blocking opsonization is the first half of escaping phagocytic clearance.
Haematogenous Dissemination Serum resistance is the precondition for bloodstream survival.
Show evidence (1 reference)
PMID:35489793 SUPPORT Other
"The gonococcus is able to subvert complement mediated killing and opsonisation by sialylation of its lipooligosaccharide and deploys a series of anti-phagocytic mechanisms."
Directly states LOS sialylation as the mechanism subverting complement killing and opsonization.
Anti-Phagocytic Survival Within Neutrophils
The organism deploys a series of anti-phagocytic mechanisms that allow it to survive within neutrophils rather than be killed by them. The cells recruited to clear the infection become a niche for it, which is why a florid neutrophilic exudate coexists with persistent viable organisms.
neutrophil CL:0000775 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves neutrophil (CL:0000775). CL:0000775 is a cell type from the Cell Ontology.
Downstream
Neutrophil Influx and Immunopathological Tissue Damage Failure of neutrophil killing sustains the inflammatory response that damages host tissue.
Show evidence (1 reference)
PMID:35489793 SUPPORT Other
"The gonococcus is able to subvert complement mediated killing and opsonisation by sialylation of its lipooligosaccharide and deploys a series of anti-phagocytic mechanisms."
Establishes the anti-phagocytic mechanisms this node represents.
Neutrophil Influx and Immunopathological Tissue Damage
Gonococcal pathology is substantially immunopathological rather than directly cytotoxic. Sustained neutrophil influx that fails to clear the organism releases reactive oxygen species, proteases, and defensins that damage the host mucosa, producing the purulent discharge that is the clinical hallmark of infection.
neutrophil CL:0000775 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves neutrophil (CL:0000775). CL:0000775 is a cell type from the Cell Ontology.
neutrophil degranulation GO:0043312 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased neutrophil degranulation (GO:0043312). GO:0043312 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Urethritis Neutrophilic urethral inflammation produces purulent discharge and dysuria.
Cervicitis Neutrophilic endocervical inflammation produces mucopurulent cervicitis.
Abnormal vaginal discharge Cervical inflammatory exudate presents as abnormal discharge.
Dysuria Urethral inflammation causes painful micturition.
Epididymitis Retrograde spread from the urethra inflames the epididymis.
Pharyngitis Pharyngeal colonization may produce inflammation, though it is usually asymptomatic.
Show evidence (1 reference)
PMID:35489793 SUPPORT Other
"The gonococcus is able to subvert complement mediated killing and opsonisation by sialylation of its lipooligosaccharide and deploys a series of anti-phagocytic mechanisms."
PARTIAL: supports the failure of phagocytic clearance that sustains the neutrophil influx, rather than the tissue-damage step itself.
Absence of Protective Immunity and Reinfection
Because surface antigens vary continuously and the organism subverts both complement and phagocytic killing, infection does not generate protective immunity. Reinfection after treatment is the rule rather than the exception, which is the central obstacle to both control and vaccine development.
Show evidence (1 reference)
PMID:35642527 SUPPORT Human Clinical
"Prior observational studies have suggested that OMV-based meningococcal serogroup B vaccines confer protection against gonorrhea."
PARTIAL: the reliance on a cross-protective meningococcal vaccine, in the absence of any gonorrhea-specific one, reflects the immunological problem this node describes without stating it directly.
Ascending Genital Tract Infection and Tubal Damage
Spread from the endocervix to the endometrium and fallopian tubes produces salpingitis and pelvic inflammatory disease. Inflammatory damage to the tubal epithelium causes ciliated-cell loss, scarring, and eventual occlusion - the substrate for tubal-factor infertility and ectopic pregnancy.
Downstream
Salpingitis Direct inflammation of the fallopian tube.
Female infertility Tubal scarring and occlusion cause tubal-factor infertility.
Ectopic pregnancy Tubal scarring impairs ovum transport, predisposing to tubal implantation.
Pelvic pain Chronic post-inflammatory change produces chronic pelvic pain.
Perihepatitis Transperitoneal spread from the tubes to the hepatic capsule produces the Fitz-Hugh-Curtis syndrome.
Show evidence (1 reference)
PMID:12346974 SUPPORT Human Clinical
"Chlamydia trachomatis, Neisseria gonorrhoeae, or both cause PID in at least 50% of cases."
Directly attributes at least half of pelvic inflammatory disease to N. gonorrhoeae and C. trachomatis, the causal step this node asserts.
Haematogenous Dissemination
Serum-resistant strains that survive in the bloodstream seed distant sites, producing disseminated gonococcal infection - the classic triad of migratory polyarthralgia, tenosynovitis, and pustular dermatitis, with frank septic arthritis in a subset. Terminal complement pathway deficiency removes the principal bactericidal barrier and is a recognized host risk factor for recurrent or disseminated disease.
CFI hgnc:5394 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves CFI (hgnc:5394). hgnc:5394 is a gene from the HUGO Gene Nomenclature Committee. C6 hgnc:1339 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves C6 (hgnc:1339). hgnc:1339 is a gene from the HUGO Gene Nomenclature Committee. C7 hgnc:1346 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves C7 (hgnc:1346). hgnc:1346 is a gene from the HUGO Gene Nomenclature Committee. C9 hgnc:1358 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves C9 (hgnc:1358). hgnc:1358 is a gene from the HUGO Gene Nomenclature Committee. CFH hgnc:4883 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves CFH (hgnc:4883). hgnc:4883 is a gene from the HUGO Gene Nomenclature Committee.
Downstream
Arthritis Seeding of joints produces gonococcal septic arthritis.
Tenosynovitis Seeding of tendon sheaths produces the tenosynovitis of the DGI triad.
Skin rash Seeding of skin produces the pustular dermatitis of the DGI triad.
Show evidence (2 references)
PMID:6415361 SUPPORT Human Clinical
"There were 19 cases of suppurative arthritis (Group II) and 30 cases with only tenosynovitis, skin lesions, or both (Group I)."
Quantifies the manifestation split across 49 prospectively studied patients, supporting all three downstream phenotypes of this node - arthritis, tenosynovitis, and skin lesions.
PMID:41607490 SUPPORT Human Clinical
"Complement studies showed low total (CH50) and alternative pathway (AP50) activity and low levels of all alternative and terminal complement proteins and the complement inhibitors factor H and factor I (FI), suggesting uninhibited complement activation and complement consumption."
Documents a complement-deficient host developing disseminated infection, supporting complement integrity as the barrier whose loss permits dissemination.
Perinatal Conjunctival Inoculation
Passage through an infected birth canal inoculates the neonatal conjunctiva, producing a hyperacute purulent conjunctivitis that can perforate the cornea and blind the infant within days if untreated. This is the rationale for universal neonatal ocular prophylaxis.
Downstream
Conjunctivitis Conjunctival infection produces gonococcal ophthalmia neonatorum.
Show evidence (1 reference)
PMID:8771523 SUPPORT Human Clinical
"Ophthalmia neonatorum still blinds approximately 10,000 babies annually worldwide."
Quantifies the blindness burden that makes perinatal conjunctival inoculation clinically consequential.
Gonococcal Penicillin-Binding Protein Cross-Linking (Ceftriaxone Target)
Gonococcal peptidoglycan cross-linking by penicillin-binding proteins is the target of ceftriaxone, the sole remaining recommended first-line agent. Beta-lactam acylation of the PBP active site halts cross-linking and is bactericidal.
peptidoglycan-based cell wall biogenesis GO:0009273 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased peptidoglycan-based cell wall biogenesis (GO:0009273). GO:0009273 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
penA Mosaic Alleles and Cephalosporin Resistance Alteration of the PBP2 target reduces beta-lactam binding affinity.
Show evidence (1 reference)
PMID:35416971 SUPPORT Human Clinical
"The 2021 CDC STI Treatment Guidelines now recommend 500mg ceftriaxone intramuscularly once for the treatment of uncomplicated gonorrhea at all anatomic sites."
Establishes ceftriaxone as the recommended first-line agent acting on this target.
penA Mosaic Alleles and Cephalosporin Resistance
Mosaic penA alleles encode an altered penicillin-binding protein 2 with reduced beta-lactam binding affinity, giving reduced susceptibility or frank resistance to extended-spectrum cephalosporins. Mosaic alleles are assembled by horizontal transfer from commensal Neisseria species carried in the oropharynx, which makes pharyngeal infection an important site of resistance emergence. Ceftriaxone MICs have so far remained stable in US surveillance, but resistant strains have been reported internationally.
response to antibiotic GO:0046677 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased response to antibiotic (GO:0046677). GO:0046677 is a biological process from the Gene Ontology. ↑ INCREASED
Show evidence (1 reference)
PMID:35416971 SUPPORT Human Clinical
"GISP data suggest that ceftriaxone minimal inhibitory concentrations (MICs) have remained stable in the United States"
Gives the current US surveillance position on ceftriaxone susceptibility that this resistance node tracks against.
Gonococcal Ribosomal Translation (Macrolide and Tetracycline Target)
Gonococcal protein synthesis is the target of azithromycin, formerly given with ceftriaxone as dual therapy, and of the doxycycline used to cover concurrent chlamydial infection.
translation GO:0006412 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased translation (GO:0006412). GO:0006412 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
Azithromycin Resistance and the Retreat to Monotherapy Rising resistance at this target removed azithromycin from the recommended regimen.
Show evidence (1 reference)
PMID:35416971 SUPPORT Human Clinical
"If coinfection with chlamydia has not been excluded, cotreatment with doxycycline 100mg twice daily for 7 days should be added."
Establishes doxycycline, a ribosome-targeting agent, as part of current management.
Azithromycin Resistance and the Retreat to Monotherapy
Azithromycin resistance rose rapidly after the 2015 dual-therapy recommendation, driven by 23S rRNA target mutations and by upregulation of the MtrC-MtrD-MtrE efflux pump. The consequence is a rare example of guideline retreat: the 2021 CDC guidelines dropped azithromycin and returned to ceftriaxone monotherapy at a higher dose, explicitly weighing antimicrobial stewardship against dual coverage.
response to antibiotic GO:0046677 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased response to antibiotic (GO:0046677). GO:0046677 is a biological process from the Gene Ontology. ↑ INCREASED
Show evidence (2 references)
PMID:35416971 SUPPORT Human Clinical
"Since the release of the Centers for Disease Control and Prevention (CDC) 2015 STD Treatment Guidelines, azithromycin, part of the 2015 dual-drug treatment regimen, has had a rapid rise in resistance."
Directly documents the rise in azithromycin resistance that drove the guideline change.
PMID:35416971 SUPPORT Human Clinical
"GISP documented a rapid rise in the proportion of isolates with an elevated MIC"
Documents the rise in azithromycin MICs in US surveillance.
Sequential Loss of Antimicrobial Classes
N. gonorrhoeae has developed resistance to every first-line therapy deployed against it in turn - sulfonamides, penicillins, tetracyclines, and fluoroquinolones - leaving ceftriaxone as the last reliably effective option against a thin development pipeline. This node captures the population-level trajectory that the individual resistance nodes are instances of, and it is the sharpest contrast with the treponematoses, where penicillin has remained curative for eight decades.
Show evidence (2 references)
PMID:35416971 SUPPORT Human Clinical
"Neisseria gonorrhoeae has developed resistance to all first-line recommended therapies, making gonococcal antimicrobial resistance a major public health concern given limited antibiotic options currently and an even smaller antimicrobial development pipeline."
Directly states the sequential loss of every first-line therapy and the thin replacement pipeline.
PMID:35489793 SUPPORT Other
"there has been a surge in gonorrhoea cases that has been exacerbated by the rapid rise in gonococcal multidrug resistance to all useful antimicrobials resulting in this organism becoming a significant public health burden"
Independently corroborates multidrug resistance to all useful antimicrobials as a driver of the current disease burden.
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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Gonorrhea Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
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Phenotypes

16
Cardiovascular 1
Conjunctivitis HP:0000509 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Ophthalmia neonatorum, annotated with Conjunctivitis (HP:0000509), qualified as temporality acute. HP:0000509 is a phenotype from the Human Phenotype Ontology.
Temporal: ACUTE
Show evidence (1 reference)
PMID:8771523 SUPPORT Human Clinical
"Ophthalmia neonatorum still blinds approximately 10,000 babies annually worldwide."
Quantifies the global blindness burden attributable to ophthalmia neonatorum.
Genitourinary 2
Dysuria HP:0100518 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Dysuria (HP:0100518). HP:0100518 is a phenotype from the Human Phenotype Ontology.
No evidence item is attached; no cited source in this entry describes dysuria, so it is curated as unevidenced description rather than supported by a disease-level quote.
Female infertility HP:0008222 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Female infertility (HP:0008222). HP:0008222 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:12346974 SUPPORT Human Clinical
"Chlamydia trachomatis, Neisseria gonorrhoeae, or both cause PID in at least 50% of cases."
Establishes gonococcal causation of PID, the antecedent of the tubal-factor infertility this phenotype records.
PMID:23007248 SUPPORT Human Clinical
"Pelvic inflammatory disease (PID) is the most significant complication of sexually transmitted infections in childbearing-age women and it represents an important public health problem because of its long-term sequelae (chronic pelvic pain, tubal infertility, ectopic pregnancy)."
Names tubal infertility among the long-term sequelae of pelvic inflammatory disease.
Immune 1
Skin rash HP:0000988 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Pustular dermatitis, annotated with Skin rash (HP:0000988). HP:0000988 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:6415361 SUPPORT Human Clinical
"Twenty-seven Group I patients (90%) had skin lesions compared to 8 Group II patients (42%)"
Records skin lesions in both disseminated gonococcal infection subgroups. No frequency band is asserted: these denominators are DGI subgroups, not patients with gonorrhea.
Musculoskeletal 1
Arthritis HP:0001369 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Arthritis (HP:0001369). HP:0001369 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:6112797 SUPPORT Human Clinical
"Disseminated gonococcal infection (DGI) and gonococcal arthritis (GCA)"
Establishes gonococcal arthritis as a recognized manifestation of disseminated infection. The snippet is the article title because this 1981 record has no abstract in PubMed.
PMID:6415361 SUPPORT Human Clinical
"There were 19 cases of suppurative arthritis (Group II) and 30 cases with only tenosynovitis, skin lesions, or both (Group I)."
Gives suppurative arthritis in 19 of 49 prospectively studied patients with disseminated gonococcal infection.
Respiratory 1
Pharyngitis HP:0025439 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Pharyngitis (HP:0025439). HP:0025439 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:35416971 SUPPORT Human Clinical
"there are no recommended alternative therapies for N gonorrhoeae infection of the throat"
Supports the therapeutic significance of pharyngeal infection recorded in this description.
Constitutional 1
Pelvic pain HP:0034267 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Pelvic pain (HP:0034267), qualified as temporality chronic. HP:0034267 is a phenotype from the Human Phenotype Ontology.
Temporal: CHRONIC
Show evidence (1 reference)
PMID:23007248 SUPPORT Human Clinical
"Pelvic inflammatory disease (PID) is the most significant complication of sexually transmitted infections in childbearing-age women and it represents an important public health problem because of its long-term sequelae (chronic pelvic pain, tubal infertility, ectopic pregnancy)."
Names chronic pelvic pain among the long-term sequelae of pelvic inflammatory disease.
Other 9
Urethritis HP:0500006 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Urethritis (HP:0500006). HP:0500006 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:35489793 SUPPORT Other
"Neisseria gonorrhoeae is an obligate human pathogen that is the cause of the sexually transmitted disease gonorrhoea."
PARTIAL: anchors the disease entity; the urethral presentation itself is not described by a quotable sentence in the sources cached here.
Cervicitis HP:0030160 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Cervicitis (HP:0030160). HP:0030160 is a phenotype from the Human Phenotype Ontology.
No evidence item is attached, for the same reason as Dysuria.
Abnormal vaginal discharge HP:0034269 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Abnormal vaginal discharge (HP:0034269). HP:0034269 is a phenotype from the Human Phenotype Ontology.
No evidence item is attached; curated as unevidenced description.
Epididymitis HP:0000031 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Epididymitis (HP:0000031). HP:0000031 is a phenotype from the Human Phenotype Ontology.
No evidence item is attached; curated as unevidenced description.
Salpingitis HP:0034492 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Salpingitis (HP:0034492). HP:0034492 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23007248 SUPPORT Human Clinical
"Pelvic inflammatory disease (PID) is the most significant complication of sexually transmitted infections in childbearing-age women and it represents an important public health problem because of its long-term sequelae (chronic pelvic pain, tubal infertility, ectopic pregnancy)."
Establishes pelvic inflammatory disease as the major sequela of STIs and names the three long-term consequences this node's downstream edges assert.
Ectopic pregnancy
No term binding: HP:0031456 Ectopic pregnancy exists in HPO but is not reachable from the PhenotypeTerm dynamic-enum root, so it fails enum validation. A free-text preferred_term is used rather than forcing a wrong-but-valid term. Candidate for an HPO placement fix or new-term request, alongside the condylomata lata and chancre gaps noted in the Syphilis entry.
Show evidence (1 reference)
PMID:23007248 SUPPORT Human Clinical
"Pelvic inflammatory disease (PID) is the most significant complication of sexually transmitted infections in childbearing-age women and it represents an important public health problem because of its long-term sequelae (chronic pelvic pain, tubal infertility, ectopic pregnancy)."
Names ectopic pregnancy among the long-term sequelae of pelvic inflammatory disease.
Perihepatitis
No term binding: HPO has no perihepatitis or Fitz-Hugh-Curtis term, so a free-text preferred_term is used rather than forcing a broader hepatic or peritoneal term that would misdescribe the lesion. Candidate for an HPO new-term request.
Show evidence (1 reference)
PMID:6769152 SUPPORT Human Clinical
"The Fitz-Hugh--Curtis syndrome is an extragenital manifestation of gonorrhea, characterized by fibrinous inflammation of the subphrenic area with violinstring-like adhesions between the liver surface and the parietal peritoneum."
Defines the syndrome, its gonococcal aetiology, and the adhesion morphology this phenotype records.
Asymptomatic infection
No term binding: HPO has no term for asymptomatic infection, which is an absence of phenotype rather than a phenotypic abnormality. Curated with a free-text preferred_term because omitting it entirely would misrepresent the disease.
Show evidence (1 reference)
PMID:15653780 SUPPORT Human Clinical
"However, most sexually transmitted infections (STIs) are asymptomatic-contributing to underdiagnosis estimated at 50% or more."
PARTIAL: establishes that most STIs are asymptomatic and that this drives underdiagnosis. The statement is across STIs rather than specific to gonorrhea, so it supports the pattern rather than a gonorrhea-specific proportion.
Tenosynovitis HP:6001438 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Tenosynovitis (HP:6001438). HP:6001438 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:6415361 SUPPORT Human Clinical
"Twenty-six Group I patients had tenosynovitis (87%)"
Records tenosynovitis in 26 of the 30 non-suppurative disseminated gonococcal infection patients. No frequency band is asserted: the denominator is a DGI subgroup, not patients with gonorrhea.
🧬

Genetic Associations

7
CFI (Complement factor I deficiency predisposing to disseminated gonococcal infection)
Gene: CFI hgnc:5394 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is CFI (hgnc:5394). hgnc:5394 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: SUSCEPTIBILITY
Show evidence (2 references)
PMID:41607490 SUPPORT Human Clinical
"Complement studies showed low total (CH50) and alternative pathway (AP50) activity and low levels of all alternative and terminal complement proteins and the complement inhibitors factor H and factor I (FI), suggesting uninhibited complement activation and complement consumption."
Documents the complement profile in a patient with factor I deficiency who developed disseminated gonococcal infection.
PMID:6415361 SUPPORT Human Clinical
"This patient and one other were found to have complement abnormalities."
PARTIAL: documents complement abnormalities in patients from a disseminated-infection series, supporting the association without identifying the gene.
C6 (Terminal complement component deficiency predisposing to disseminated neisserial infection)
Gene: C6 hgnc:1339 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is C6 (hgnc:1339). hgnc:1339 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: SUSCEPTIBILITY
Show evidence (3 references)
PMID:6415361 SUPPORT Human Clinical
"This patient and one other were found to have complement abnormalities."
PARTIAL: supports complement abnormality as a host factor in disseminated gonococcal infection without naming the gene.
PMID:1554498 SUPPORT Other
"The particularly frequent occurrence of terminal complement deficiencies in patients with Neisserial infections suggests that the cytolytic activity of the complement system is important in resistance to Neisseria meningitidis."
Establishes the class-level association between terminal complement deficiency and neisserial infection. The sentence names no individual gene and its worked example is Neisseria meningitidis, so it supports the complement-class mechanism rather than a gene-specific claim. Evidence source is OTHER because the citation is a review.
PMID:1554498 SUPPORT Other
"Thus it has been established that two types of deficiencies exist (at least for C6, C7 and C8): one with low but detectable amounts of the component and the other with a complete absence of the protein in question."
Names this gene explicitly among the inherited terminal-component deficiencies, anchoring the entry at gene level rather than by class alone.
C7 (Terminal complement component deficiency predisposing to disseminated neisserial infection)
Gene: C7 hgnc:1346 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is C7 (hgnc:1346). hgnc:1346 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: SUSCEPTIBILITY
Show evidence (3 references)
PMID:6415361 SUPPORT Human Clinical
"This patient and one other were found to have complement abnormalities."
PARTIAL: supports complement abnormality as a host factor without naming the gene.
PMID:1554498 SUPPORT Other
"The particularly frequent occurrence of terminal complement deficiencies in patients with Neisserial infections suggests that the cytolytic activity of the complement system is important in resistance to Neisseria meningitidis."
Establishes the class-level association between terminal complement deficiency and neisserial infection. The sentence names no individual gene and its worked example is Neisseria meningitidis, so it supports the complement-class mechanism rather than a gene-specific claim. Evidence source is OTHER because the citation is a review.
PMID:1554498 SUPPORT Other
"Thus it has been established that two types of deficiencies exist (at least for C6, C7 and C8): one with low but detectable amounts of the component and the other with a complete absence of the protein in question."
Names this gene explicitly among the inherited terminal-component deficiencies, anchoring the entry at gene level rather than by class alone.
C9 (Terminal complement component deficiency predisposing to disseminated neisserial infection)
Gene: C9 hgnc:1358 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is C9 (hgnc:1358). hgnc:1358 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: SUSCEPTIBILITY
Show evidence (2 references)
PMID:6415361 SUPPORT Human Clinical
"This patient and one other were found to have complement abnormalities."
PARTIAL: supports complement abnormality as a host factor without naming the gene.
PMID:1554498 SUPPORT Other
"The particularly frequent occurrence of terminal complement deficiencies in patients with Neisserial infections suggests that the cytolytic activity of the complement system is important in resistance to Neisseria meningitidis."
Establishes the class-level association between terminal complement deficiency and neisserial infection. The sentence names no individual gene and its worked example is Neisseria meningitidis, so it supports the complement-class mechanism rather than a gene-specific claim. Evidence source is OTHER because the citation is a review.
C8A (Terminal complement component deficiency (C8 alpha-gamma subunit) predisposing to disseminated neisserial infection)
Gene: C8A hgnc:1352 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is C8A (hgnc:1352). hgnc:1352 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: SUSCEPTIBILITY
Show evidence (2 references)
PMID:1554498 SUPPORT Other
"The particularly frequent occurrence of terminal complement deficiencies in patients with Neisserial infections suggests that the cytolytic activity of the complement system is important in resistance to Neisseria meningitidis."
Establishes the class-level association between terminal complement deficiency and neisserial infection. The sentence names no individual gene and its worked example is Neisseria meningitidis, so it supports the complement-class mechanism rather than a gene-specific claim. Evidence source is OTHER because the citation is a review.
PMID:1554498 SUPPORT Other
"Thus it has been established that two types of deficiencies exist (at least for C6, C7 and C8): one with low but detectable amounts of the component and the other with a complete absence of the protein in question."
PARTIAL: the source names C8 as an inherited terminal-component deficiency but does not say which subunit gene is affected. Inherited C8 deficiency arises from either the alpha-gamma or the beta subunit, so this entry curates both without claiming the source distinguishes them.
C8B (Terminal complement component deficiency (C8 beta subunit) predisposing to disseminated neisserial infection)
Gene: C8B hgnc:1353 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is C8B (hgnc:1353). hgnc:1353 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: SUSCEPTIBILITY
Show evidence (2 references)
PMID:1554498 SUPPORT Other
"The particularly frequent occurrence of terminal complement deficiencies in patients with Neisserial infections suggests that the cytolytic activity of the complement system is important in resistance to Neisseria meningitidis."
Establishes the class-level association between terminal complement deficiency and neisserial infection. The sentence names no individual gene and its worked example is Neisseria meningitidis, so it supports the complement-class mechanism rather than a gene-specific claim. Evidence source is OTHER because the citation is a review.
PMID:1554498 SUPPORT Other
"Thus it has been established that two types of deficiencies exist (at least for C6, C7 and C8): one with low but detectable amounts of the component and the other with a complete absence of the protein in question."
PARTIAL: the source names C8 as an inherited terminal-component deficiency but does not say which subunit gene is affected. Inherited C8 deficiency arises from either the alpha-gamma or the beta subunit, so this entry curates both without claiming the source distinguishes them.
CFH (Complement regulator deficiency predisposing to disseminated gonococcal infection)
Gene: CFH hgnc:4883 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is CFH (hgnc:4883). hgnc:4883 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: SUSCEPTIBILITY
Show evidence (1 reference)
PMID:41607490 SUPPORT Human Clinical
"low levels of all alternative and terminal complement proteins and the complement inhibitors factor H and factor I (FI), suggesting uninhibited complement activation and complement consumption"
Documents depletion of factor H alongside factor I in a patient with disseminated gonococcal infection.
💊

Medical Actions

3
Ceftriaxone 500 mg intramuscular single dose
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: ceftriaxone CHEBI:29007 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses ceftriaxone (CHEBI:29007). CHEBI:29007 is a therapeutic agent from Chemical Entities of Biological Interest.
Ceftriaxone 500 mg IM as a single dose is the recommended first-line treatment for uncomplicated gonorrhea at all anatomic sites, with 1 g for persons weighing 150 kg or more. The 2021 guidance raised the dose and returned to monotherapy, dropping the azithromycin component of the previous dual regimen because of rising macrolide resistance and antimicrobial stewardship considerations. Few alternatives exist for cephalosporin-allergic patients, and there are no recommended alternative regimens for pharyngeal infection.
Mechanism Target:
INHIBITS Gonococcal Penicillin-Binding Protein Cross-Linking (Ceftriaxone Target) — Beta-lactam acylation of penicillin-binding proteins halts peptidoglycan cross-linking and is bactericidal.
Show evidence (2 references)
PMID:35416971 SUPPORT Human Clinical
"The 2021 CDC STI Treatment Guidelines now recommend 500mg ceftriaxone intramuscularly once for the treatment of uncomplicated gonorrhea at all anatomic sites."
Gives the recommended regimen directly.
PMID:35416971 SUPPORT Human Clinical
"Few alternative therapies exist for persons with cephalosporin allergies; there are no recommended alternative therapies for N gonorrhoeae infection of the throat."
Supports the constrained-alternatives caveat recorded in this description.
Doxycycline cotreatment for possible chlamydial coinfection
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: doxycycline CHEBI:50845 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses doxycycline (CHEBI:50845). CHEBI:50845 is a therapeutic agent from Chemical Entities of Biological Interest.
Doxycycline 100 mg orally twice daily for seven days is added when chlamydial coinfection has not been excluded. This is coverage of a coinfecting organism rather than gonococcal therapy - doxycycline is not adequate treatment for gonorrhea itself.
Mechanism Target:
INHIBITS Gonococcal Ribosomal Translation (Macrolide and Tetracycline Target) — Doxycycline binds the 30S ribosomal subunit and arrests bacterial protein synthesis.
Show evidence (1 reference)
PMID:35416971 SUPPORT Human Clinical
"If coinfection with chlamydia has not been excluded, cotreatment with doxycycline 100mg twice daily for 7 days should be added."
Gives the cotreatment indication and regimen directly.
Meningococcal serogroup B outer-membrane-vesicle vaccination
Category: Therapeutic Action: VaccinationNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Vaccination (NCIT:C15346). NCIT:C15346 is a clinical intervention from the NCI Thesaurus. NCIT:C15346
No gonorrhea-specific vaccine exists. Outer-membrane-vesicle meningococcal serogroup B vaccines, principally 4CMenB, confer partial cross-protection through antigenic homology between the two Neisseria species. A matched cohort study found gonorrhea rates 46% lower in 4CMenB recipients than in MenACWY recipients, and pooled meta-analysis supports a partial protective effect. This is partial, not sterilizing, protection - it reduces incidence rather than preventing infection.
Show evidence (4 references)
PMID:35642527 SUPPORT Human Clinical
"In adjusted analyses, gonorrhea rates were 46% lower among recipients of 4CMenB vs MenACWY"
Gives the matched-cohort effect estimate for 4CMenB against gonorrhea.
PMID:40334533 SUPPORT Human Clinical
"OMV vaccines offer moderate protection against gonorrhoea."
States the meta-analysis conclusion directly: OMV vaccines confer moderate, not sterilizing, protection.
PMID:38986746 SUPPORT Human Clinical
"Vaccine effectiveness and impact of meningococcal vaccines against gonococcal infections"
A second independent systematic review of meningococcal vaccine effectiveness against gonococcal infection.
+ 1 more reference
🔬

Diagnosis

2
Nucleic acid amplification testing
NAAT is the diagnostic method of choice at all anatomic sites, including rectal and pharyngeal specimens where culture performs poorly. Because extragenital infection is usually asymptomatic, site-specific NAAT testing is what makes case-finding possible in the populations that sustain transmission.
nucleic acid amplification testing NCIT:C17003 NCI Thesaurus (NCIT)
Results: Detection of N. gonorrhoeae nucleic acid from urine or from urethral, cervical, rectal, or pharyngeal swabs.
Show evidence (2 references)
PMID:20335410 SUPPORT Human Clinical
"This study evaluated the performance of culture and nucleic acid amplification tests (NAATs) for rectal chlamydial and gonococcal diagnosis."
Establishes NAAT evaluation against culture for extragenital gonococcal diagnosis.
PMID:18520976 SUPPORT Human Clinical
"Nucleic acid amplification tests in the diagnosis of chlamydial and gonococcal infections of the oropharynx and rectum in men who have sex with men"
Establishes NAAT use for oropharyngeal and rectal gonococcal diagnosis in the population where extragenital infection is most prevalent.
Culture with antimicrobial susceptibility testing
Culture retains a specific role that NAAT cannot fill: it is the only method that yields an isolate for susceptibility testing. In an organism that has sequentially defeated every drug class, surveillance culture is what detects the next resistance wave, and it is indicated in suspected treatment failure.
bacterial culture and susceptibility testing NCIT:C25294 NCI Thesaurus (NCIT)
Results: Growth of N. gonorrhoeae with minimum inhibitory concentrations for ceftriaxone, azithromycin, and other agents.
Show evidence (1 reference)
PMID:35416971 SUPPORT Human Clinical
"GISP data suggest that ceftriaxone minimal inhibitory concentrations (MICs) have remained stable in the United States"
The GISP surveillance MIC data this node exists to generate are reported directly, establishing the role of culture-based susceptibility testing.
🦠

Infectious Agent

1
Neisseria gonorrhoeae
A Gram-negative diplococcus of the family Neisseriaceae. An obligate human pathogen with no environmental or animal reservoir, transmitted only by direct mucosal contact - sexual or perinatal.
Neisseria gonorrhoeae NCBITaxon:485 NCBI Taxonomy (NCBITaxon)
Show evidence (1 reference)
PMID:35489793 SUPPORT Other
"Neisseria gonorrhoeae is an obligate human pathogen that is the cause of the sexually transmitted disease gonorrhoea."
Identifies the causative organism and its obligate human host restriction. Evidence source is OTHER because the citation is a review chapter.
↔️

Transmission

2
Sexual mucosal transmission
Transmission occurs by direct mucosal contact during vaginal, anal, or oral sex, seeding the urethral, cervical, rectal, or pharyngeal epithelium.
Show evidence (1 reference)
PMID:35489793 SUPPORT Other
"The gonococcus initially colonises and adheres to host mucosal surfaces utilising a type IV pilus that helps with microcolony formation."
Establishes mucosal surfaces as the site of initial colonization, which is what direct mucosal contact delivers the organism to.
Perinatal transmission during delivery
Passage through an infected birth canal inoculates the neonatal conjunctiva, producing gonococcal ophthalmia neonatorum.
Show evidence (1 reference)
PMID:8771523 SUPPORT Human Clinical
"Ophthalmia neonatorum still blinds approximately 10,000 babies annually worldwide."
Establishes perinatally acquired ophthalmia neonatorum as a globally significant, sight-threatening consequence of maternal infection.
🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from Gonorrhea:

Chlamydial urethritis and cervicitis
Overlapping Features Chlamydia trachomatis causes a clinically indistinguishable urethritis and cervicitis and frequently coinfects, which is why current guidance adds doxycycline when chlamydial coinfection has not been excluded.
Non-gonococcal urethritis
Overlapping Features Mycoplasma genitalium, Trichomonas vaginalis, and Ureaplasma species cause urethritis with a typically less purulent discharge; distinguished by NAAT.
Reactive arthritis
Overlapping Features Post-infectious reactive arthritis can follow gonococcal or chlamydial infection and mimics disseminated gonococcal arthritis, but joint cultures are sterile and the mechanism is immune-mediated rather than septic.
🐁

Animal Models

1
Mouse
Mice are naturally resistant to genital gonococcal infection, and the standard model therefore requires 17-beta-estradiol treatment to permit colonization of the female genital tract. This is the central caveat of gonococcal animal work: the model is a hormonally manipulated surrogate rather than a natural infection, and the organism is an obligate human pathogen with several key virulence factors that are human-specific.
Species
Mouse
Show evidence (3 references)
PMID:21747807 SUPPORT Model Organism
"Genital tract infection can be established in female mice that are treated with 17β-estradiol, however, and many features of experimental murine infection mimic human infection."
States both halves of the model's position - infection requires estradiol treatment, and many but not all features mimic human infection. The HUMAN_MODEL_MISMATCH discussion records where the resemblance breaks down.
PMID:28886683 SUPPORT Other
"Refinements of the animal model have also improved its use as a surrogate host of human infection and accelerated the testing of novel therapeutic and prophylactic compounds against gonococcal infection."
Independently characterizes the murine system as a surrogate host whose usefulness rests on refinements, corroborating the caveat this model entry records. Evidence source is OTHER because the citation is a review.
PMID:2506350 SUPPORT Model Organism
"Mice of these strains, therefore, appear resistant to gonococcal infection of the genital tract."
States the murine resistance directly, which is what makes hormonal manipulation necessary for the model to work.
{ }

Source YAML

click to show 
name: Gonorrhea
creation_date: "2026-08-08T13:20:00Z"
category: Infectious Disease
description: >-
  Gonorrhea is a sexually transmitted infection caused by the Gram-negative
  diplococcus Neisseria gonorrhoeae, an obligate human pathogen with no
  environmental or animal reservoir. It colonizes the mucosal epithelium of the
  urethra, cervix, rectum, pharynx, and conjunctiva, and is frequently
  asymptomatic - particularly at rectal and pharyngeal sites - which sustains
  onward transmission. Ascending infection causes pelvic inflammatory disease
  and tubal infertility; haematogenous spread causes disseminated gonococcal
  infection; and perinatal transmission causes ophthalmia neonatorum. Two
  features dominate its pathophysiology. First, the organism varies its surface
  antigens continuously and subverts complement and phagocytic killing, so
  infection elicits no protective immunity and reinfection is the rule. Second,
  it has sequentially acquired resistance to every antimicrobial class deployed
  against it - sulfonamides, penicillins, tetracyclines, and fluoroquinolones -
  leaving ceftriaxone as the last reliably effective first-line agent. This is
  the mechanistic inverse of syphilis, which after eight decades has still
  never developed clinically significant penicillin resistance.
synonyms:
- gonococcal infection
- the clap
disease_term:
  preferred_term: gonorrhea
  term:
    id: MONDO:0004277
    label: gonorrhea
parents:
- Bacterial Infection
- Sexually transmitted infection
classifications:
  harrisons_chapter:
  - classification_value: INFECTIOUS_DISEASES
    evidence:
    - reference: PMID:35489793
      reference_title: "Neisseria gonorrhoeae physiology and pathogenesis."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Neisseria gonorrhoeae is an obligate human pathogen that is the cause of the sexually transmitted disease gonorrhoea."
      explanation: >-
        Gonorrhea is a bacterial infection treated with antimicrobials, placing
        it in Harrison's Infectious Diseases Part.
infectious_agent:
- name: Neisseria gonorrhoeae
  description: >-
    A Gram-negative diplococcus of the family Neisseriaceae. An obligate human
    pathogen with no environmental or animal reservoir, transmitted only by
    direct mucosal contact - sexual or perinatal.
  infectious_agent_term:
    preferred_term: Neisseria gonorrhoeae
    term:
      id: NCBITaxon:485
      label: Neisseria gonorrhoeae
  evidence:
  - reference: PMID:35489793
    reference_title: "Neisseria gonorrhoeae physiology and pathogenesis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Neisseria gonorrhoeae is an obligate human pathogen that is the cause of the sexually transmitted disease gonorrhoea."
    explanation: >-
      Identifies the causative organism and its obligate human host
      restriction. Evidence source is OTHER because the citation is a review
      chapter.
transmission:
- name: Sexual mucosal transmission
  description: >-
    Transmission occurs by direct mucosal contact during vaginal, anal, or oral
    sex, seeding the urethral, cervical, rectal, or pharyngeal epithelium.
  evidence:
  - reference: PMID:35489793
    reference_title: "Neisseria gonorrhoeae physiology and pathogenesis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The gonococcus initially colonises and adheres to host mucosal surfaces utilising a type IV pilus that helps with microcolony formation."
    explanation: >-
      Establishes mucosal surfaces as the site of initial colonization, which
      is what direct mucosal contact delivers the organism to.
- name: Perinatal transmission during delivery
  description: >-
    Passage through an infected birth canal inoculates the neonatal
    conjunctiva, producing gonococcal ophthalmia neonatorum.
  evidence:
  - reference: PMID:8771523
    reference_title: "The influence of perinatal infective factors on ophthalmia neonatorum."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Ophthalmia neonatorum still blinds approximately 10,000 babies annually worldwide."
    explanation: >-
      Establishes perinatally acquired ophthalmia neonatorum as a globally
      significant, sight-threatening consequence of maternal infection.
pathophysiology:
- name: Gonococcal Mucosal Attachment and Microcolony Formation
  biological_scale: TISSUE
  description: >-
    The gonococcus adheres to mucosal epithelium using type IV pili, which
    mediate initial long-range attachment and microcolony formation, with the
    porin PorB and the phase-variable outer membrane protein Opa providing
    additional adhesion. This is the trigger event of the pathograph.
  cell_types:
  - preferred_term: epithelial cell
    term:
      id: CL:0000066
      label: epithelial cell
  biological_processes:
  - preferred_term: cell adhesion
    term:
      id: GO:0007155
      label: cell adhesion
    modifier: INCREASED
  downstream:
  - target: Opa-CEACAM Engagement and Epithelial Invasion
    description: Adherent organisms engage host receptors and invade the epithelium.
    causal_link_type: DIRECT
  - target: Asymptomatic infection
    description: >-
      Colonization can persist without provoking the neutrophilic
      immunopathology that produces symptoms, which is the usual outcome at
      rectal and pharyngeal sites.
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:35489793
    reference_title: "Neisseria gonorrhoeae physiology and pathogenesis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The gonococcus initially colonises and adheres to host mucosal surfaces utilising a type IV pilus that helps with microcolony formation."
    explanation: >-
      Directly describes type IV pilus-mediated attachment and microcolony
      formation as the initiating step.
  - reference: PMID:35489793
    reference_title: "Neisseria gonorrhoeae physiology and pathogenesis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Other adhesion strategies include the porin, PorB, and the phase variable outer membrane protein Opa."
    explanation: Names the additional adhesins this node carries.
- name: Opa-CEACAM Engagement and Epithelial Invasion
  biological_scale: CELLULAR
  description: >-
    Opa proteins bind CEACAM family receptors on epithelial cells, neutrophils,
    and lymphocytes, driving receptor-mediated invasion and transcytosis of the
    epithelial layer. CEACAM engagement is not obligatory - Opa-expressing
    gonococci can also adhere to and invade genital epithelial cells by a
    CEACAM-independent route - so this node models the dominant pathway rather
    than the only one.
  cell_types:
  - preferred_term: epithelial cell
    term:
      id: CL:0000066
      label: epithelial cell
  biological_processes:
  - preferred_term: symbiont entry into host
    term:
      id: GO:0044409
      label: symbiont entry into host
    modifier: INCREASED
  downstream:
  - target: Neutrophil Influx and Immunopathological Tissue Damage
    description: >-
      Epithelial invasion provokes the acute inflammatory response that
      produces the clinical disease.
    causal_link_type: DIRECT
  - target: Ascending Genital Tract Infection and Tubal Damage
    description: >-
      Invasion of the endocervical epithelium permits upward spread to the
      upper genital tract.
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:21204865
    reference_title: "Opa proteins and CEACAMs: pathways of immune engagement for pathogenic Neisseria."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "These Opa variants are able to bind to different receptors of the CEACAM family on epithelial cells, neutrophils, and T and B lymphocytes, influencing the innate and adaptive immune responses."
    explanation: >-
      Establishes Opa-CEACAM binding across the cell types this node names.
      Evidence source is OTHER because the citation is a review.
  - reference: PMID:11580753
    reference_title: "CEACAM is not necessary for Neisseria gonorrhoeae to adhere to and invade female genital epithelial cells."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "when CEACAM is expressed, Opa+ gonococci exploit it for the adherence to and invasion of these cells."
    explanation: >-
      PARTIAL, and deliberately included as a qualifier rather than a support:
      it establishes that the CEACAM route is not obligatory, which is why this
      node is worded as the dominant pathway rather than the only one.
- name: Pilin and Opa Antigenic and Phase Variation
  biological_scale: MOLECULAR
  role: immune_evasion
  description: >-
    Pilin undergoes high-frequency antigenic variation by recombination with
    silent pilS loci, and the Opa paralogs undergo phase variation by
    slipped-strand mispairing. The resulting within-host antigenic diversity
    keeps the adaptive response chasing a moving target. This is the direct
    mechanistic counterpart of TprK gene conversion in Treponema pallidum - the
    same evolutionary solution reached by an unrelated organism.
  downstream:
  - target: Absence of Protective Immunity and Reinfection
    description: >-
      Continuous surface-antigen turnover prevents the development of
      protective immune memory.
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:21204865
    reference_title: "Opa proteins and CEACAMs: pathways of immune engagement for pathogenic Neisseria."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "These Opa variants are able to bind to different receptors of the CEACAM family on epithelial cells, neutrophils, and T and B lymphocytes, influencing the innate and adaptive immune responses."
    explanation: >-
      PARTIAL: establishes the existence of multiple Opa variants engaging
      immune cells, the substrate on which phase variation acts, without
      describing the variation mechanism itself.
  notes: >-
    The pilS recombination and slipped-strand mispairing mechanisms are
    described in the deep-research report but no cached source in this entry
    quotes them directly, so they are asserted in the description without a
    dedicated evidence item rather than propped up by an off-target quote.
- name: Lipooligosaccharide Sialylation and Complement Evasion
  biological_scale: MOLECULAR
  role: immune_evasion
  description: >-
    The gonococcus sialylates its lipooligosaccharide using host-derived
    CMP-N-acetylneuraminic acid, masking the molecule and blocking complement
    activation and opsonophagocytic killing. This serum resistance is what
    permits survival in the bloodstream during dissemination.
  biological_processes:
  - preferred_term: complement activation
    term:
      id: GO:0006956
      label: complement activation
    modifier: DECREASED
  downstream:
  - target: Anti-Phagocytic Survival Within Neutrophils
    description: >-
      Blocking opsonization is the first half of escaping phagocytic clearance.
    causal_link_type: DIRECT
  - target: Haematogenous Dissemination
    description: Serum resistance is the precondition for bloodstream survival.
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:35489793
    reference_title: "Neisseria gonorrhoeae physiology and pathogenesis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The gonococcus is able to subvert complement mediated killing and opsonisation by sialylation of its lipooligosaccharide and deploys a series of anti-phagocytic mechanisms."
    explanation: >-
      Directly states LOS sialylation as the mechanism subverting complement
      killing and opsonization.
- name: Anti-Phagocytic Survival Within Neutrophils
  biological_scale: CELLULAR
  role: immune_evasion
  description: >-
    The organism deploys a series of anti-phagocytic mechanisms that allow it
    to survive within neutrophils rather than be killed by them. The cells
    recruited to clear the infection become a niche for it, which is why a
    florid neutrophilic exudate coexists with persistent viable organisms.
  cell_types:
  - preferred_term: neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  downstream:
  - target: Neutrophil Influx and Immunopathological Tissue Damage
    description: >-
      Failure of neutrophil killing sustains the inflammatory response that
      damages host tissue.
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:35489793
    reference_title: "Neisseria gonorrhoeae physiology and pathogenesis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The gonococcus is able to subvert complement mediated killing and opsonisation by sialylation of its lipooligosaccharide and deploys a series of anti-phagocytic mechanisms."
    explanation: Establishes the anti-phagocytic mechanisms this node represents.
- name: Neutrophil Influx and Immunopathological Tissue Damage
  biological_scale: TISSUE
  description: >-
    Gonococcal pathology is substantially immunopathological rather than
    directly cytotoxic. Sustained neutrophil influx that fails to clear the
    organism releases reactive oxygen species, proteases, and defensins that
    damage the host mucosa, producing the purulent discharge that is the
    clinical hallmark of infection.
  cell_types:
  - preferred_term: neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  biological_processes:
  - preferred_term: neutrophil degranulation
    term:
      id: GO:0043312
      label: neutrophil degranulation
    modifier: INCREASED
  downstream:
  - target: Urethritis
    description: Neutrophilic urethral inflammation produces purulent discharge and dysuria.
    causal_link_type: DIRECT
  - target: Cervicitis
    description: Neutrophilic endocervical inflammation produces mucopurulent cervicitis.
    causal_link_type: DIRECT
  - target: Abnormal vaginal discharge
    description: Cervical inflammatory exudate presents as abnormal discharge.
    causal_link_type: DIRECT
  - target: Dysuria
    description: Urethral inflammation causes painful micturition.
    causal_link_type: DIRECT
  - target: Epididymitis
    description: Retrograde spread from the urethra inflames the epididymis.
    causal_link_type: DIRECT
  - target: Pharyngitis
    description: >-
      Pharyngeal colonization may produce inflammation, though it is usually
      asymptomatic.
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:35489793
    reference_title: "Neisseria gonorrhoeae physiology and pathogenesis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The gonococcus is able to subvert complement mediated killing and opsonisation by sialylation of its lipooligosaccharide and deploys a series of anti-phagocytic mechanisms."
    explanation: >-
      PARTIAL: supports the failure of phagocytic clearance that sustains the
      neutrophil influx, rather than the tissue-damage step itself.
- name: Absence of Protective Immunity and Reinfection
  biological_scale: ORGANISM
  description: >-
    Because surface antigens vary continuously and the organism subverts both
    complement and phagocytic killing, infection does not generate protective
    immunity. Reinfection after treatment is the rule rather than the
    exception, which is the central obstacle to both control and vaccine
    development.
  evidence:
  - reference: PMID:35642527
    reference_title: "Prevention of Neisseria gonorrhoeae With Meningococcal B Vaccine: A Matched Cohort Study in Southern California."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Prior observational studies have suggested that OMV-based meningococcal serogroup B vaccines confer protection against gonorrhea."
    explanation: >-
      PARTIAL: the reliance on a cross-protective meningococcal vaccine, in the
      absence of any gonorrhea-specific one, reflects the immunological problem
      this node describes without stating it directly.
- name: Ascending Genital Tract Infection and Tubal Damage
  biological_scale: TISSUE
  description: >-
    Spread from the endocervix to the endometrium and fallopian tubes produces
    salpingitis and pelvic inflammatory disease. Inflammatory damage to the
    tubal epithelium causes ciliated-cell loss, scarring, and eventual
    occlusion - the substrate for tubal-factor infertility and ectopic
    pregnancy.
  downstream:
  - target: Salpingitis
    description: Direct inflammation of the fallopian tube.
    causal_link_type: DIRECT
  - target: Female infertility
    description: Tubal scarring and occlusion cause tubal-factor infertility.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
  - target: Ectopic pregnancy
    description: >-
      Tubal scarring impairs ovum transport, predisposing to tubal
      implantation.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
  - target: Pelvic pain
    description: Chronic post-inflammatory change produces chronic pelvic pain.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
  - target: Perihepatitis
    description: >-
      Transperitoneal spread from the tubes to the hepatic capsule produces
      the Fitz-Hugh-Curtis syndrome.
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:12346974
    reference_title: "Immunopathogenesis of pelvic inflammatory disease and infertility -- what do we know and what shall we do?"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Chlamydia trachomatis, Neisseria gonorrhoeae, or both cause PID in at least 50% of cases."
    explanation: >-
      Directly attributes at least half of pelvic inflammatory disease to
      N. gonorrhoeae and C. trachomatis, the causal step this node asserts.
- name: Haematogenous Dissemination
  biological_scale: ORGANISM
  description: >-
    Serum-resistant strains that survive in the bloodstream seed distant sites,
    producing disseminated gonococcal infection - the classic triad of
    migratory polyarthralgia, tenosynovitis, and pustular dermatitis, with
    frank septic arthritis in a subset. Terminal complement pathway deficiency
    removes the principal bactericidal barrier and is a recognized host risk
    factor for recurrent or disseminated disease.
  genes:
  - preferred_term: CFI
    term:
      id: hgnc:5394
      label: CFI
  - preferred_term: C6
    term:
      id: hgnc:1339
      label: C6
  - preferred_term: C7
    term:
      id: hgnc:1346
      label: C7
  - preferred_term: C9
    term:
      id: hgnc:1358
      label: C9
  - preferred_term: CFH
    term:
      id: hgnc:4883
      label: CFH
  downstream:
  - target: Arthritis
    description: Seeding of joints produces gonococcal septic arthritis.
    causal_link_type: DIRECT
  - target: Tenosynovitis
    description: Seeding of tendon sheaths produces the tenosynovitis of the DGI triad.
    causal_link_type: DIRECT
  - target: Skin rash
    description: Seeding of skin produces the pustular dermatitis of the DGI triad.
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:6415361
    reference_title: "Disseminated gonococcal infection: a prospective analysis of 49 patients and a review of pathophysiology and immune mechanisms."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "There were 19 cases of suppurative arthritis (Group II) and 30 cases with only tenosynovitis, skin lesions, or both (Group I)."
    explanation: >-
      Quantifies the manifestation split across 49 prospectively studied
      patients, supporting all three downstream phenotypes of this node -
      arthritis, tenosynovitis, and skin lesions.
  - reference: PMID:41607490
    reference_title: "Disseminated gonococcal infection secondary to a rare homozygous mutation resulting in complement factor I deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Complement studies showed low total (CH50) and alternative pathway (AP50) activity and low levels of all alternative and terminal complement proteins and the complement inhibitors factor H and factor I (FI), suggesting uninhibited complement activation and complement consumption."
    explanation: >-
      Documents a complement-deficient host developing disseminated infection,
      supporting complement integrity as the barrier whose loss permits
      dissemination.
- name: Perinatal Conjunctival Inoculation
  biological_scale: TISSUE
  description: >-
    Passage through an infected birth canal inoculates the neonatal
    conjunctiva, producing a hyperacute purulent conjunctivitis that can
    perforate the cornea and blind the infant within days if untreated. This is
    the rationale for universal neonatal ocular prophylaxis.
  downstream:
  - target: Conjunctivitis
    description: Conjunctival infection produces gonococcal ophthalmia neonatorum.
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:8771523
    reference_title: "The influence of perinatal infective factors on ophthalmia neonatorum."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Ophthalmia neonatorum still blinds approximately 10,000 babies annually worldwide."
    explanation: >-
      Quantifies the blindness burden that makes perinatal conjunctival
      inoculation clinically consequential.
- name: Gonococcal Penicillin-Binding Protein Cross-Linking (Ceftriaxone Target)
  biological_scale: MOLECULAR
  role: therapeutic_vulnerability
  conforms_to: "bacterial_cell_wall_synthesis_inhibition#Peptidoglycan Cross-Linking by Penicillin-Binding Proteins"
  description: >-
    Gonococcal peptidoglycan cross-linking by penicillin-binding proteins is
    the target of ceftriaxone, the sole remaining recommended first-line agent.
    Beta-lactam acylation of the PBP active site halts cross-linking and is
    bactericidal.
  biological_processes:
  - preferred_term: peptidoglycan-based cell wall biogenesis
    term:
      id: GO:0009273
      label: peptidoglycan-based cell wall biogenesis
    modifier: DECREASED
  downstream:
  - target: penA Mosaic Alleles and Cephalosporin Resistance
    description: >-
      Alteration of the PBP2 target reduces beta-lactam binding affinity.
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:35416971
    reference_title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The 2021 CDC STI Treatment Guidelines now recommend 500mg ceftriaxone intramuscularly once for the treatment of uncomplicated gonorrhea at all anatomic sites."
    explanation: >-
      Establishes ceftriaxone as the recommended first-line agent acting on
      this target.
- name: penA Mosaic Alleles and Cephalosporin Resistance
  biological_scale: MOLECULAR
  role: resistance_mechanism
  conforms_to: "bacterial_cell_wall_synthesis_inhibition#Acquired Resistance and Drug Inactivation"
  description: >-
    Mosaic penA alleles encode an altered penicillin-binding protein 2 with
    reduced beta-lactam binding affinity, giving reduced susceptibility or
    frank resistance to extended-spectrum cephalosporins. Mosaic alleles are
    assembled by horizontal transfer from commensal Neisseria species carried
    in the oropharynx, which makes pharyngeal infection an important site of
    resistance emergence. Ceftriaxone MICs have so far remained stable in US
    surveillance, but resistant strains have been reported internationally.
  biological_processes:
  - preferred_term: response to antibiotic
    term:
      id: GO:0046677
      label: response to antibiotic
    modifier: INCREASED
  evidence:
  - reference: PMID:35416971
    reference_title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "GISP data suggest that ceftriaxone minimal inhibitory concentrations (MICs) have remained stable in the United States"
    explanation: >-
      Gives the current US surveillance position on ceftriaxone susceptibility
      that this resistance node tracks against.
  notes: >-
    The specific molecular mechanism - mosaic penA encoding an altered PBP2,
    and horizontal acquisition from commensal Neisseria - is described in the
    deep-research report but is not quoted by any source cached in this entry.
    It is asserted in the description without a dedicated evidence item rather
    than supported by an off-target quote. A dedicated penA reference would
    strengthen this node.
- name: Gonococcal Ribosomal Translation (Macrolide and Tetracycline Target)
  biological_scale: MOLECULAR
  role: therapeutic_vulnerability
  conforms_to: "bacterial_protein_synthesis_inhibition#Bacterial mRNA Translation by the Ribosome"
  description: >-
    Gonococcal protein synthesis is the target of azithromycin, formerly given
    with ceftriaxone as dual therapy, and of the doxycycline used to cover
    concurrent chlamydial infection.
  biological_processes:
  - preferred_term: translation
    term:
      id: GO:0006412
      label: translation
    modifier: DECREASED
  downstream:
  - target: Azithromycin Resistance and the Retreat to Monotherapy
    description: >-
      Rising resistance at this target removed azithromycin from the
      recommended regimen.
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:35416971
    reference_title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "If coinfection with chlamydia has not been excluded, cotreatment with doxycycline 100mg twice daily for 7 days should be added."
    explanation: >-
      Establishes doxycycline, a ribosome-targeting agent, as part of current
      management.
- name: Azithromycin Resistance and the Retreat to Monotherapy
  biological_scale: MOLECULAR
  role: resistance_mechanism
  conforms_to: "bacterial_protein_synthesis_inhibition#Ribosomal Target Resistance"
  description: >-
    Azithromycin resistance rose rapidly after the 2015 dual-therapy
    recommendation, driven by 23S rRNA target mutations and by upregulation of
    the MtrC-MtrD-MtrE efflux pump. The consequence is a rare example of
    guideline retreat: the 2021 CDC guidelines dropped azithromycin and
    returned to ceftriaxone monotherapy at a higher dose, explicitly weighing
    antimicrobial stewardship against dual coverage.
  biological_processes:
  - preferred_term: response to antibiotic
    term:
      id: GO:0046677
      label: response to antibiotic
    modifier: INCREASED
  evidence:
  - reference: PMID:35416971
    reference_title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Since the release of the Centers for Disease Control and Prevention (CDC) 2015 STD Treatment Guidelines, azithromycin, part of the 2015 dual-drug treatment regimen, has had a rapid rise in resistance."
    explanation: >-
      Directly documents the rise in azithromycin resistance that drove the
      guideline change.
  - reference: PMID:35416971
    reference_title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "GISP documented a rapid rise in the proportion of isolates with an elevated MIC"
    explanation: Documents the rise in azithromycin MICs in US surveillance.
  notes: >-
    The specific determinants - 23S rRNA A2059G/C2611T and mtrR-mediated
    MtrCDE efflux upregulation - come from the deep-research report and are not
    quoted by any source cached here. They are asserted in the description
    without a dedicated evidence item.
- name: Sequential Loss of Antimicrobial Classes
  biological_scale: ORGANISM
  description: >-
    N. gonorrhoeae has developed resistance to every first-line therapy
    deployed against it in turn - sulfonamides, penicillins, tetracyclines, and
    fluoroquinolones - leaving ceftriaxone as the last reliably effective
    option against a thin development pipeline. This node captures the
    population-level trajectory that the individual resistance nodes are
    instances of, and it is the sharpest contrast with the treponematoses,
    where penicillin has remained curative for eight decades.
  evidence:
  - reference: PMID:35416971
    reference_title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Neisseria gonorrhoeae has developed resistance to all first-line recommended therapies, making gonococcal antimicrobial resistance a major public health concern given limited antibiotic options currently and an even smaller antimicrobial development pipeline."
    explanation: >-
      Directly states the sequential loss of every first-line therapy and the
      thin replacement pipeline.
  - reference: PMID:35489793
    reference_title: "Neisseria gonorrhoeae physiology and pathogenesis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "there has been a surge in gonorrhoea cases that has been exacerbated by the rapid rise in gonococcal multidrug resistance to all useful antimicrobials resulting in this organism becoming a significant public health burden"
    explanation: >-
      Independently corroborates multidrug resistance to all useful
      antimicrobials as a driver of the current disease burden.
genetic:
- name: CFI
  association: Complement factor I deficiency predisposing to disseminated gonococcal infection
  notes: >-
    Complement factor I deficiency causes uninhibited complement activation and consumption, depleting alternative and terminal pathway components. The resulting loss of complement-mediated bactericidal activity removes the principal barrier to gonococcal bloodstream survival and predisposes to disseminated gonococcal infection. This is host susceptibility to an exogenous infection, not a cause of gonorrhea.
  relationship_type: SUSCEPTIBILITY
  gene_term:
    preferred_term: CFI
    term:
      id: hgnc:5394
      label: CFI
  evidence:
  - reference: PMID:41607490
    reference_title: "Disseminated gonococcal infection secondary to a rare homozygous mutation resulting in complement factor I deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Complement studies showed low total (CH50) and alternative pathway (AP50) activity and low levels of all alternative and terminal complement proteins and the complement inhibitors factor H and factor I (FI), suggesting uninhibited complement activation and complement consumption."
    explanation: >-
      Documents the complement profile in a patient with factor I deficiency
      who developed disseminated gonococcal infection.
  - reference: PMID:6415361
    reference_title: "Disseminated gonococcal infection: a prospective analysis of 49 patients and a review of pathophysiology and immune mechanisms."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This patient and one other were found to have complement abnormalities."
    explanation: >-
      PARTIAL: documents complement abnormalities in patients from a
      disseminated-infection series, supporting the association without
      identifying the gene.
- name: C6
  association: Terminal complement component deficiency predisposing to disseminated neisserial infection
  notes: >-
    Terminal complement component deficiency prevents assembly of the membrane attack complex, abolishing serum bactericidal activity against Neisseria species and predisposing to recurrent and disseminated neisserial infection.
  relationship_type: SUSCEPTIBILITY
  gene_term:
    preferred_term: C6
    term:
      id: hgnc:1339
      label: C6
  evidence:
  - reference: PMID:6415361
    reference_title: "Disseminated gonococcal infection: a prospective analysis of 49 patients and a review of pathophysiology and immune mechanisms."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This patient and one other were found to have complement abnormalities."
    explanation: >-
      PARTIAL: supports complement abnormality as a host factor in
      disseminated gonococcal infection without naming the gene.
  - reference: PMID:1554498
    reference_title: "Inherited deficiencies of the terminal components of human complement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The particularly frequent occurrence of terminal complement deficiencies in patients with Neisserial infections suggests that the cytolytic activity of the complement system is important in resistance to Neisseria meningitidis."
    explanation: >-
      Establishes the class-level association between terminal complement
      deficiency and neisserial infection. The sentence names no individual
      gene and its worked example is Neisseria meningitidis, so it supports
      the complement-class mechanism rather than a gene-specific claim.
      Evidence source is OTHER because the citation is a review.
  - reference: PMID:1554498
    reference_title: "Inherited deficiencies of the terminal components of human complement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Thus it has been established that two types of deficiencies exist (at least for C6, C7 and C8): one with low but detectable amounts of the component and the other with a complete absence of the protein in question."
    explanation: >-
      Names this gene explicitly among the inherited terminal-component
      deficiencies, anchoring the entry at gene level rather than by class
      alone.
- name: C7
  association: Terminal complement component deficiency predisposing to disseminated neisserial infection
  notes: >-
    Terminal complement component deficiency, mechanistically equivalent to C6 deficiency in abolishing membrane attack complex assembly.
  relationship_type: SUSCEPTIBILITY
  gene_term:
    preferred_term: C7
    term:
      id: hgnc:1346
      label: C7
  evidence:
  - reference: PMID:6415361
    reference_title: "Disseminated gonococcal infection: a prospective analysis of 49 patients and a review of pathophysiology and immune mechanisms."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This patient and one other were found to have complement abnormalities."
    explanation: >-
      PARTIAL: supports complement abnormality as a host factor without naming
      the gene.
  - reference: PMID:1554498
    reference_title: "Inherited deficiencies of the terminal components of human complement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The particularly frequent occurrence of terminal complement deficiencies in patients with Neisserial infections suggests that the cytolytic activity of the complement system is important in resistance to Neisseria meningitidis."
    explanation: >-
      Establishes the class-level association between terminal complement
      deficiency and neisserial infection. The sentence names no individual
      gene and its worked example is Neisseria meningitidis, so it supports
      the complement-class mechanism rather than a gene-specific claim.
      Evidence source is OTHER because the citation is a review.
  - reference: PMID:1554498
    reference_title: "Inherited deficiencies of the terminal components of human complement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Thus it has been established that two types of deficiencies exist (at least for C6, C7 and C8): one with low but detectable amounts of the component and the other with a complete absence of the protein in question."
    explanation: >-
      Names this gene explicitly among the inherited terminal-component
      deficiencies, anchoring the entry at gene level rather than by class
      alone.
- name: C9
  association: Terminal complement component deficiency predisposing to disseminated neisserial infection
  notes: >-
    Terminal complement component deficiency; C9 completes the membrane attack
    complex, and its deficiency is a recognized predisposition to neisserial
    infection. C9 rests on the class-level terminal-complement association
    only: the gene-naming sentence in PMID:1554498 lists C6, C7 and C8, and C9
    appears nowhere in that abstract, so no gene-level anchor is claimed for
    it. A source naming C9 deficiency directly would upgrade this entry the way
    PMID:1554498 upgraded C6 and C7.
  relationship_type: SUSCEPTIBILITY
  gene_term:
    preferred_term: C9
    term:
      id: hgnc:1358
      label: C9
  evidence:
  - reference: PMID:6415361
    reference_title: "Disseminated gonococcal infection: a prospective analysis of 49 patients and a review of pathophysiology and immune mechanisms."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This patient and one other were found to have complement abnormalities."
    explanation: >-
      PARTIAL: supports complement abnormality as a host factor without naming
      the gene.
  - reference: PMID:1554498
    reference_title: "Inherited deficiencies of the terminal components of human complement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The particularly frequent occurrence of terminal complement deficiencies in patients with Neisserial infections suggests that the cytolytic activity of the complement system is important in resistance to Neisseria meningitidis."
    explanation: >-
      Establishes the class-level association between terminal complement
      deficiency and neisserial infection. The sentence names no individual
      gene and its worked example is Neisseria meningitidis, so it supports
      the complement-class mechanism rather than a gene-specific claim.
      Evidence source is OTHER because the citation is a review.
- name: C8A
  association: Terminal complement component deficiency (C8 alpha-gamma subunit) predisposing to disseminated neisserial infection
  notes: >-
    Inherited C8 deficiency is genetically heterogeneous: the C8 protein is a
    heterotrimer, and deficiency arises from loss of either the alpha-gamma
    subunit (C8A) or the beta subunit (C8B). PMID:1554498 names C8 as a class
    without disambiguating, so both subunit genes are curated and neither is
    claimed to be the one the source meant.
  relationship_type: SUSCEPTIBILITY
  gene_term:
    preferred_term: C8A
    term:
      id: hgnc:1352
      label: C8A
  evidence:
  - reference: PMID:1554498
    reference_title: "Inherited deficiencies of the terminal components of human complement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The particularly frequent occurrence of terminal complement deficiencies in patients with Neisserial infections suggests that the cytolytic activity of the complement system is important in resistance to Neisseria meningitidis."
    explanation: >-
      Establishes the class-level association between terminal complement
      deficiency and neisserial infection. The sentence names no individual
      gene and its worked example is Neisseria meningitidis, so it supports
      the complement-class mechanism rather than a gene-specific claim.
      Evidence source is OTHER because the citation is a review.
  - reference: PMID:1554498
    reference_title: "Inherited deficiencies of the terminal components of human complement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Thus it has been established that two types of deficiencies exist (at least for C6, C7 and C8): one with low but detectable amounts of the component and the other with a complete absence of the protein in question."
    explanation: >-
      PARTIAL: the source names C8 as an inherited terminal-component
      deficiency but does not say which subunit gene is affected. Inherited C8
      deficiency arises from either the alpha-gamma or the beta subunit, so
      this entry curates both without claiming the source distinguishes them.
- name: C8B
  association: Terminal complement component deficiency (C8 beta subunit) predisposing to disseminated neisserial infection
  notes: >-
    Curated alongside C8A for the reason given there - the source names C8 as a
    class and does not identify the subunit gene.
  relationship_type: SUSCEPTIBILITY
  gene_term:
    preferred_term: C8B
    term:
      id: hgnc:1353
      label: C8B
  evidence:
  - reference: PMID:1554498
    reference_title: "Inherited deficiencies of the terminal components of human complement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The particularly frequent occurrence of terminal complement deficiencies in patients with Neisserial infections suggests that the cytolytic activity of the complement system is important in resistance to Neisseria meningitidis."
    explanation: >-
      Establishes the class-level association between terminal complement
      deficiency and neisserial infection. The sentence names no individual
      gene and its worked example is Neisseria meningitidis, so it supports
      the complement-class mechanism rather than a gene-specific claim.
      Evidence source is OTHER because the citation is a review.
  - reference: PMID:1554498
    reference_title: "Inherited deficiencies of the terminal components of human complement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Thus it has been established that two types of deficiencies exist (at least for C6, C7 and C8): one with low but detectable amounts of the component and the other with a complete absence of the protein in question."
    explanation: >-
      PARTIAL: the source names C8 as an inherited terminal-component
      deficiency but does not say which subunit gene is affected. Inherited C8
      deficiency arises from either the alpha-gamma or the beta subunit, so
      this entry curates both without claiming the source distinguishes them.
- name: CFH
  association: Complement regulator deficiency predisposing to disseminated gonococcal infection
  notes: >-
    Complement factor H is a regulator rather than a component; its deficiency causes uncontrolled alternative-pathway activation and consumption, with the same net loss of bactericidal capacity as terminal-component deficiency. Factor H was among the inhibitors found depleted in the factor-I-deficient patient with disseminated infection.
  relationship_type: SUSCEPTIBILITY
  gene_term:
    preferred_term: CFH
    term:
      id: hgnc:4883
      label: CFH
  evidence:
  - reference: PMID:41607490
    reference_title: "Disseminated gonococcal infection secondary to a rare homozygous mutation resulting in complement factor I deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "low levels of all alternative and terminal complement proteins and the complement inhibitors factor H and factor I (FI), suggesting uninhibited complement activation and complement consumption"
    explanation: >-
      Documents depletion of factor H alongside factor I in a patient with
      disseminated gonococcal infection.
phenotypes:
- category: Genitourinary
  name: Urethritis
  diagnostic: true
  description: >-
    Purulent urethral discharge with dysuria is the characteristic symptomatic
    presentation in men, appearing within days of exposure.
  phenotype_term:
    preferred_term: Urethritis
    term:
      id: HP:0500006
      label: Urethritis
  evidence:
  - reference: PMID:35489793
    reference_title: "Neisseria gonorrhoeae physiology and pathogenesis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Neisseria gonorrhoeae is an obligate human pathogen that is the cause of the sexually transmitted disease gonorrhoea."
    explanation: >-
      PARTIAL: anchors the disease entity; the urethral presentation itself is
      not described by a quotable sentence in the sources cached here.
- category: Genitourinary
  name: Dysuria
  description: Painful micturition accompanies urethral inflammation.
  phenotype_term:
    preferred_term: Dysuria
    term:
      id: HP:0100518
      label: Dysuria
  notes: >-
    No evidence item is attached; no cited source in this entry describes
    dysuria, so it is curated as unevidenced description rather than supported
    by a disease-level quote.
- category: Genitourinary
  name: Cervicitis
  description: >-
    Mucopurulent endocervical inflammation is the counterpart presentation in
    women, and is frequently asymptomatic - the reason infection in women is so
    often detected only at the stage of complications.
  phenotype_term:
    preferred_term: Cervicitis
    term:
      id: HP:0030160
      label: Cervicitis
  notes: No evidence item is attached, for the same reason as Dysuria.
- category: Genitourinary
  name: Abnormal vaginal discharge
  description: Cervical inflammatory exudate presents as abnormal vaginal discharge.
  phenotype_term:
    preferred_term: Abnormal vaginal discharge
    term:
      id: HP:0034269
      label: Abnormal vaginal discharge
  notes: No evidence item is attached; curated as unevidenced description.
- category: Genitourinary
  name: Epididymitis
  description: >-
    Retrograde spread from the urethra produces epididymitis, the commonest
    local complication in men.
  phenotype_term:
    preferred_term: Epididymitis
    term:
      id: HP:0000031
      label: Epididymitis
  notes: No evidence item is attached; curated as unevidenced description.
- category: Otolaryngological
  name: Pharyngitis
  description: >-
    Pharyngeal infection is usually asymptomatic. Its importance is that it
    resists treatment - there are no recommended alternative regimens for
    pharyngeal infection - and serves as a reservoir for horizontal transfer of
    resistance determinants from commensal Neisseria.
  phenotype_term:
    preferred_term: Pharyngitis
    term:
      id: HP:0025439
      label: Pharyngitis
  evidence:
  - reference: PMID:35416971
    reference_title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "there are no recommended alternative therapies for N gonorrhoeae infection of the throat"
    explanation: >-
      Supports the therapeutic significance of pharyngeal infection recorded in
      this description.
- category: Genitourinary
  name: Salpingitis
  description: >-
    Ascending infection inflames the fallopian tube, the defining lesion of
    gonococcal pelvic inflammatory disease.
  phenotype_term:
    preferred_term: Salpingitis
    term:
      id: HP:0034492
      label: Salpingitis
  evidence:
  - reference: PMID:23007248
    reference_title: "Pelvic inflammatory disease (PID) from Chlamydia trachomatis versus PID from Neisseria gonorrhea: from clinical suspicion to therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Pelvic inflammatory disease (PID) is the most significant complication of sexually transmitted infections in childbearing-age women and it represents an important public health problem because of its long-term sequelae (chronic pelvic pain, tubal infertility, ectopic pregnancy)."
    explanation: >-
      Establishes pelvic inflammatory disease as the major sequela of STIs and
      names the three long-term consequences this node's downstream edges
      assert.
- category: Genitourinary
  name: Female infertility
  description: >-
    Tubal scarring and occlusion following salpingitis cause tubal-factor
    infertility, the most consequential long-term sequela of untreated
    infection.
  phenotype_term:
    preferred_term: Female infertility
    term:
      id: HP:0008222
      label: Female infertility
  evidence:
  - reference: PMID:12346974
    reference_title: "Immunopathogenesis of pelvic inflammatory disease and infertility -- what do we know and what shall we do?"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Chlamydia trachomatis, Neisseria gonorrhoeae, or both cause PID in at least 50% of cases."
    explanation: >-
      Establishes gonococcal causation of PID, the antecedent of the
      tubal-factor infertility this phenotype records.
  - reference: PMID:23007248
    reference_title: "Pelvic inflammatory disease (PID) from Chlamydia trachomatis versus PID from Neisseria gonorrhea: from clinical suspicion to therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Pelvic inflammatory disease (PID) is the most significant complication of sexually transmitted infections in childbearing-age women and it represents an important public health problem because of its long-term sequelae (chronic pelvic pain, tubal infertility, ectopic pregnancy)."
    explanation: >-
      Names tubal infertility among the long-term sequelae of pelvic
      inflammatory disease.
- category: Genitourinary
  name: Ectopic pregnancy
  description: >-
    Tubal scarring impairs ovum transport and predisposes to tubal
    implantation.
  phenotype_term:
    preferred_term: Ectopic pregnancy
  evidence:
  - reference: PMID:23007248
    reference_title: "Pelvic inflammatory disease (PID) from Chlamydia trachomatis versus PID from Neisseria gonorrhea: from clinical suspicion to therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Pelvic inflammatory disease (PID) is the most significant complication of sexually transmitted infections in childbearing-age women and it represents an important public health problem because of its long-term sequelae (chronic pelvic pain, tubal infertility, ectopic pregnancy)."
    explanation: >-
      Names ectopic pregnancy among the long-term sequelae of pelvic
      inflammatory disease.
  notes: >-
    No term binding: HP:0031456 Ectopic pregnancy exists in HPO but is not
    reachable from the PhenotypeTerm dynamic-enum root, so it fails enum
    validation. A free-text preferred_term is used rather than forcing a
    wrong-but-valid term. Candidate for an HPO placement fix or new-term
    request, alongside the condylomata lata and chancre gaps noted in the
    Syphilis entry.
- category: Genitourinary
  name: Pelvic pain
  description: Chronic pelvic pain follows post-inflammatory adhesion and scarring.
  phenotype_term:
    preferred_term: Pelvic pain
    term:
      id: HP:0034267
      label: Pelvic pain
    temporality: CHRONIC
  evidence:
  - reference: PMID:23007248
    reference_title: "Pelvic inflammatory disease (PID) from Chlamydia trachomatis versus PID from Neisseria gonorrhea: from clinical suspicion to therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Pelvic inflammatory disease (PID) is the most significant complication of sexually transmitted infections in childbearing-age women and it represents an important public health problem because of its long-term sequelae (chronic pelvic pain, tubal infertility, ectopic pregnancy)."
    explanation: >-
      Names chronic pelvic pain among the long-term sequelae of pelvic
      inflammatory disease.
- category: Gastrointestinal
  name: Perihepatitis
  description: >-
    The Fitz-Hugh-Curtis syndrome is perihepatitis complicating gonococcal
    pelvic infection, in which fibrinous inflammation over the liver capsule
    organizes into characteristic violin-string adhesions between the liver
    surface and the parietal peritoneum. It presents as right upper quadrant
    pain and is a classic mimic of biliary disease.
  phenotype_term:
    preferred_term: Fitz-Hugh-Curtis perihepatitis
  evidence:
  - reference: PMID:6769152
    reference_title: "[Gonorrhoic perihepatitis. Fitz-Hugh-Curtis syndrome]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The Fitz-Hugh--Curtis syndrome is an extragenital manifestation of gonorrhea, characterized by fibrinous inflammation of the subphrenic area with violinstring-like adhesions between the liver surface and the parietal peritoneum."
    explanation: >-
      Defines the syndrome, its gonococcal aetiology, and the adhesion
      morphology this phenotype records.
  notes: >-
    No term binding: HPO has no perihepatitis or Fitz-Hugh-Curtis term, so a
    free-text preferred_term is used rather than forcing a broader hepatic or
    peritoneal term that would misdescribe the lesion. Candidate for an HPO
    new-term request.
- category: Constitutional
  name: Asymptomatic infection
  description: >-
    Most gonococcal infection is asymptomatic, especially at rectal and
    pharyngeal sites and in women. This is not an incidental observation but
    the central epidemiological fact about the disease: it is why screening
    programmes exist, why extragenital NAAT testing matters, and why infection
    is so often first detected at the stage of complications.
  phenotype_term:
    preferred_term: Asymptomatic infection
  evidence:
  - reference: PMID:15653780
    reference_title: "Sexually transmitted infections and increased risk of co-infection with human immunodeficiency virus."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "However, most sexually transmitted infections (STIs) are asymptomatic-contributing to underdiagnosis estimated at 50% or more."
    explanation: >-
      PARTIAL: establishes that most STIs are asymptomatic and that this drives
      underdiagnosis. The statement is across STIs rather than specific to
      gonorrhea, so it supports the pattern rather than a gonorrhea-specific
      proportion.
  notes: >-
    No term binding: HPO has no term for asymptomatic infection, which is an
    absence of phenotype rather than a phenotypic abnormality. Curated with a
    free-text preferred_term because omitting it entirely would misrepresent
    the disease.
- category: Musculoskeletal
  name: Arthritis
  description: >-
    Gonococcal arthritis is the commonest manifestation of disseminated
    infection, presenting either as migratory polyarthralgia or as frank septic
    monoarthritis.
  phenotype_term:
    preferred_term: Arthritis
    term:
      id: HP:0001369
      label: Arthritis
  evidence:
  - reference: PMID:6112797
    reference_title: "Disseminated gonococcal infection (DGI) and gonococcal arthritis (GCA): I. Bacteriology, epidemiology, host factors, pathogen factors, and pathology."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Disseminated gonococcal infection (DGI) and gonococcal arthritis (GCA)"
    explanation: >-
      Establishes gonococcal arthritis as a recognized manifestation of
      disseminated infection. The snippet is the article title because this
      1981 record has no abstract in PubMed.
  - reference: PMID:6415361
    reference_title: "Disseminated gonococcal infection: a prospective analysis of 49 patients and a review of pathophysiology and immune mechanisms."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "There were 19 cases of suppurative arthritis (Group II) and 30 cases with only tenosynovitis, skin lesions, or both (Group I)."
    explanation: >-
      Gives suppurative arthritis in 19 of 49 prospectively studied patients
      with disseminated gonococcal infection.
- category: Musculoskeletal
  name: Tenosynovitis
  description: >-
    Tenosynovitis, typically of the wrists, hands, and ankles, is part of the
    classic disseminated gonococcal infection triad.
  phenotype_term:
    preferred_term: Tenosynovitis
    term:
      id: HP:6001438
      label: Tenosynovitis
  evidence:
  - reference: PMID:6415361
    reference_title: "Disseminated gonococcal infection: a prospective analysis of 49 patients and a review of pathophysiology and immune mechanisms."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Twenty-six Group I patients had tenosynovitis (87%)"
    explanation: >-
      Records tenosynovitis in 26 of the 30 non-suppurative disseminated
      gonococcal infection patients. No frequency band is asserted: the
      denominator is a DGI subgroup, not patients with gonorrhea.
- category: Dermatological
  name: Skin rash
  description: >-
    Scattered pustular or haemorrhagic skin lesions, usually few in number and
    acral, complete the disseminated gonococcal infection triad.
  phenotype_term:
    preferred_term: Pustular dermatitis
    term:
      id: HP:0000988
      label: Skin rash
  evidence:
  - reference: PMID:6415361
    reference_title: "Disseminated gonococcal infection: a prospective analysis of 49 patients and a review of pathophysiology and immune mechanisms."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Twenty-seven Group I patients (90%) had skin lesions compared to 8 Group II patients (42%)"
    explanation: >-
      Records skin lesions in both disseminated gonococcal infection subgroups.
      No frequency band is asserted: these denominators are DGI subgroups, not
      patients with gonorrhea.
- category: Ophthalmological
  name: Conjunctivitis
  description: >-
    Gonococcal ophthalmia neonatorum is a hyperacute purulent conjunctivitis of
    the newborn that can perforate the cornea within days and remains a
    significant cause of preventable childhood blindness worldwide.
  phenotype_term:
    preferred_term: Ophthalmia neonatorum
    term:
      id: HP:0000509
      label: Conjunctivitis
    temporality: ACUTE
  evidence:
  - reference: PMID:8771523
    reference_title: "The influence of perinatal infective factors on ophthalmia neonatorum."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Ophthalmia neonatorum still blinds approximately 10,000 babies annually worldwide."
    explanation: >-
      Quantifies the global blindness burden attributable to ophthalmia
      neonatorum.
diagnosis:
- name: Nucleic acid amplification testing
  description: >-
    NAAT is the diagnostic method of choice at all anatomic sites, including
    rectal and pharyngeal specimens where culture performs poorly. Because
    extragenital infection is usually asymptomatic, site-specific NAAT testing
    is what makes case-finding possible in the populations that sustain
    transmission.
  diagnosis_term:
    preferred_term: nucleic acid amplification testing
    term:
      id: NCIT:C17003
      label: Polymerase Chain Reaction
  results: >-
    Detection of N. gonorrhoeae nucleic acid from urine or from urethral,
    cervical, rectal, or pharyngeal swabs.
  evidence:
  - reference: PMID:20335410
    reference_title: "Nucleic acid amplification tests for diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis rectal infections."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This study evaluated the performance of culture and nucleic acid amplification tests (NAATs) for rectal chlamydial and gonococcal diagnosis."
    explanation: >-
      Establishes NAAT evaluation against culture for extragenital gonococcal
      diagnosis.
  - reference: PMID:18520976
    reference_title: "Nucleic acid amplification tests in the diagnosis of chlamydial and gonococcal infections of the oropharynx and rectum in men who have sex with men."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Nucleic acid amplification tests in the diagnosis of chlamydial and gonococcal infections of the oropharynx and rectum in men who have sex with men"
    explanation: >-
      Establishes NAAT use for oropharyngeal and rectal gonococcal diagnosis in
      the population where extragenital infection is most prevalent.
- name: Culture with antimicrobial susceptibility testing
  description: >-
    Culture retains a specific role that NAAT cannot fill: it is the only
    method that yields an isolate for susceptibility testing. In an organism
    that has sequentially defeated every drug class, surveillance culture is
    what detects the next resistance wave, and it is indicated in suspected
    treatment failure.
  diagnosis_term:
    preferred_term: bacterial culture and susceptibility testing
    term:
      id: NCIT:C25294
      label: Laboratory Procedure
  results: >-
    Growth of N. gonorrhoeae with minimum inhibitory concentrations for
    ceftriaxone, azithromycin, and other agents.
  evidence:
  - reference: PMID:35416971
    reference_title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "GISP data suggest that ceftriaxone minimal inhibitory concentrations (MICs) have remained stable in the United States"
    explanation: >-
      The GISP surveillance MIC data this node exists to generate are reported
      directly, establishing the role of culture-based susceptibility testing.
differential_diagnoses:
- name: Chlamydial urethritis and cervicitis
  description: >-
    Chlamydia trachomatis causes a clinically indistinguishable urethritis and
    cervicitis and frequently coinfects, which is why current guidance adds
    doxycycline when chlamydial coinfection has not been excluded.
- name: Non-gonococcal urethritis
  description: >-
    Mycoplasma genitalium, Trichomonas vaginalis, and Ureaplasma species cause
    urethritis with a typically less purulent discharge; distinguished by NAAT.
- name: Reactive arthritis
  description: >-
    Post-infectious reactive arthritis can follow gonococcal or chlamydial
    infection and mimics disseminated gonococcal arthritis, but joint cultures
    are sterile and the mechanism is immune-mediated rather than septic.
treatments:
- name: Ceftriaxone 500 mg intramuscular single dose
  description: >-
    Ceftriaxone 500 mg IM as a single dose is the recommended first-line
    treatment for uncomplicated gonorrhea at all anatomic sites, with 1 g for
    persons weighing 150 kg or more. The 2021 guidance raised the dose and
    returned to monotherapy, dropping the azithromycin component of the
    previous dual regimen because of rising macrolide resistance and
    antimicrobial stewardship considerations. Few alternatives exist for
    cephalosporin-allergic patients, and there are no recommended alternative
    regimens for pharyngeal infection.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: ceftriaxone
      term:
        id: CHEBI:29007
        label: ceftriaxone
  target_mechanisms:
  - target: Gonococcal Penicillin-Binding Protein Cross-Linking (Ceftriaxone Target)
    treatment_effect: INHIBITS
    description: >-
      Beta-lactam acylation of penicillin-binding proteins halts peptidoglycan
      cross-linking and is bactericidal.
  evidence:
  - reference: PMID:35416971
    reference_title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The 2021 CDC STI Treatment Guidelines now recommend 500mg ceftriaxone intramuscularly once for the treatment of uncomplicated gonorrhea at all anatomic sites."
    explanation: Gives the recommended regimen directly.
  - reference: PMID:35416971
    reference_title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Few alternative therapies exist for persons with cephalosporin allergies; there are no recommended alternative therapies for N gonorrhoeae infection of the throat."
    explanation: >-
      Supports the constrained-alternatives caveat recorded in this
      description.
- name: Doxycycline cotreatment for possible chlamydial coinfection
  description: >-
    Doxycycline 100 mg orally twice daily for seven days is added when
    chlamydial coinfection has not been excluded. This is coverage of a
    coinfecting organism rather than gonococcal therapy - doxycycline is not
    adequate treatment for gonorrhea itself.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: doxycycline
      term:
        id: CHEBI:50845
        label: doxycycline
  target_mechanisms:
  - target: Gonococcal Ribosomal Translation (Macrolide and Tetracycline Target)
    treatment_effect: INHIBITS
    description: >-
      Doxycycline binds the 30S ribosomal subunit and arrests bacterial protein
      synthesis.
  evidence:
  - reference: PMID:35416971
    reference_title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "If coinfection with chlamydia has not been excluded, cotreatment with doxycycline 100mg twice daily for 7 days should be added."
    explanation: Gives the cotreatment indication and regimen directly.
- name: Meningococcal serogroup B outer-membrane-vesicle vaccination
  description: >-
    No gonorrhea-specific vaccine exists. Outer-membrane-vesicle meningococcal
    serogroup B vaccines, principally 4CMenB, confer partial cross-protection
    through antigenic homology between the two Neisseria species. A matched
    cohort study found gonorrhea rates 46% lower in 4CMenB recipients than in
    MenACWY recipients, and pooled meta-analysis supports a partial protective
    effect. This is partial, not sterilizing, protection - it reduces incidence
    rather than preventing infection.
  therapeutic_modality: VACCINE
  action_category: THERAPEUTIC
  treatment_term:
    preferred_term: Vaccination
    term:
      id: NCIT:C15346
      label: Vaccination
  evidence:
  - reference: PMID:35642527
    reference_title: "Prevention of Neisseria gonorrhoeae With Meningococcal B Vaccine: A Matched Cohort Study in Southern California."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In adjusted analyses, gonorrhea rates were 46% lower among recipients of 4CMenB vs MenACWY"
    explanation: >-
      Gives the matched-cohort effect estimate for 4CMenB against gonorrhea.
  - reference: PMID:40334533
    reference_title: "Evaluating cross-protection: Meningococcal vaccines show effectiveness in gonorrhoea prevention - A systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "OMV vaccines offer moderate protection against gonorrhoea."
    explanation: >-
      States the meta-analysis conclusion directly: OMV vaccines confer
      moderate, not sterilizing, protection.
  - reference: PMID:38986746
    reference_title: "Vaccine effectiveness and impact of meningococcal vaccines against gonococcal infections: A systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Vaccine effectiveness and impact of meningococcal vaccines against gonococcal infections"
    explanation: >-
      A second independent systematic review of meningococcal vaccine
      effectiveness against gonococcal infection.
  - reference: PMID:42259835
    reference_title: "Pre-clinical efficacy of a candidate outer membrane vesicle gonococcal vaccine in comparison with 4CMenB."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Meningococcal vaccines MeNZB and 4CMenB (Bexsero), containing Neisseria meningitidis group B detergent-extracted outer membrane vesicles (dOMV), cross-protect against gonorrhoea with 31-59% effectiveness."
    explanation: >-
      States the cross-protection mechanism - detergent-extracted outer
      membrane vesicles - and the effectiveness range, and situates this
      partial protection against purpose-built gonococcal OMV candidates.
animal_models:
- species: Mouse
  description: >-
    Mice are naturally resistant to genital gonococcal infection, and the
    standard model therefore requires 17-beta-estradiol treatment to permit
    colonization of the female genital tract. This is the central caveat of
    gonococcal animal work: the model is a hormonally manipulated surrogate
    rather than a natural infection, and the organism is an obligate human
    pathogen with several key virulence factors that are human-specific.
  evidence:
  - reference: PMID:21747807
    reference_title: "Estradiol-Treated Female Mice as Surrogate Hosts for Neisseria gonorrhoeae Genital Tract Infections."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Genital tract infection can be established in female mice that are treated with 17β-estradiol, however, and many features of experimental murine infection mimic human infection."
    explanation: >-
      States both halves of the model's position - infection requires estradiol
      treatment, and many but not all features mimic human infection. The
      HUMAN_MODEL_MISMATCH discussion records where the resemblance breaks
      down.
  - reference: PMID:28886683
    reference_title: "Neisseria gonorrhoeae: Drug Resistance, Mouse Models, and Vaccine Development."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Refinements of the animal model have also improved its use as a surrogate host of human infection and accelerated the testing of novel therapeutic and prophylactic compounds against gonococcal infection."
    explanation: >-
      Independently characterizes the murine system as a surrogate host whose
      usefulness rests on refinements, corroborating the caveat this model
      entry records. Evidence source is OTHER because the citation is a
      review.
  - reference: PMID:2506350
    reference_title: "Resistance of mice to genital infection with Neisseria gonorrhoeae."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Mice of these strains, therefore, appear resistant to gonococcal infection of the genital tract."
    explanation: >-
      States the murine resistance directly, which is what makes hormonal
      manipulation necessary for the model to work.
discussions:
- discussion_id: gonorrhea_mouse_model_human_specificity
  kind: HUMAN_MODEL_MISMATCH
  status: OPEN
  prompt: >-
    How much of gonococcal pathogenesis established in the estradiol-treated
    mouse transfers to human infection, given that mice are naturally resistant
    and that several key gonococcal virulence factors engage human-specific
    receptors?
  rationale: >-
    N. gonorrhoeae is an obligate human pathogen. Mice are naturally resistant
    to genital infection and must be treated with 17-beta-estradiol to be
    colonized at all. Several central virulence interactions curated in this
    entry are human-restricted - Opa binding to human CEACAM receptors, and
    iron acquisition from human transferrin and lactoferrin - so the surrogate
    host lacks the very receptors the mechanism depends on. Conclusions about
    colonization, immune evasion, and vaccine protection drawn from this model
    therefore carry an unusually large translational gap.
  attaches_to:
  - pathophysiology#Opa-CEACAM Engagement and Epithelial Invasion
  - pathophysiology#Anti-Phagocytic Survival Within Neutrophils
  proposed_experiments:
  - experiment_id: exp_gonorrhea_humanized_ceacam_mouse
    name: Human CEACAM-transgenic mouse challenge
    description: >-
      Compare colonization, neutrophil interaction, and vaccine protection
      between wild-type estradiol-treated mice and mice transgenic for human
      CEACAM receptors, to quantify how much of the observed phenotype depends
      on the human-specific receptor interaction absent from the standard
      model.
  evidence:
  - reference: PMID:2506350
    reference_title: "Resistance of mice to genital infection with Neisseria gonorrhoeae."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Mice of these strains, therefore, appear resistant to gonococcal infection of the genital tract."
    explanation: >-
      The natural murine resistance is the root of the mismatch this
      discussion poses: the model must be hormonally manipulated before it will
      support infection at all.
  - reference: PMID:21204865
    reference_title: "Opa proteins and CEACAMs: pathways of immune engagement for pathogenic Neisseria."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Most immune interactions are mediated via binding to members of the carcinoembryonic antigen cell adhesion molecule (CEACAM) family."
    explanation: >-
      Establishes CEACAM engagement as the dominant immune interaction, the
      human-specific receptor family the murine model lacks.
- discussion_id: gonorrhea_omv_vaccine_mechanism
  kind: KNOWLEDGE_GAP
  status: OPEN
  prompt: >-
    Which antigens mediate the cross-protection that meningococcal OMV vaccines
    confer against gonorrhea, and can that protection be improved on
    deliberately?
  rationale: >-
    OMV meningococcal vaccines reduce gonorrhea incidence substantially, but
    the protection is partial and the responsible antigens are not definitively
    identified. Because the effect was discovered epidemiologically rather than
    designed, the mechanism is inferred from antigenic homology rather than
    demonstrated. Identifying the protective antigens would convert an
    incidental benefit into a rational vaccine target for an organism that has
    otherwise defeated every antimicrobial deployed against it.
  attaches_to:
  - pathophysiology#Absence of Protective Immunity and Reinfection
  proposed_experiments:
  - experiment_id: exp_gonorrhea_omv_antigen_deconvolution
    name: Antigen deconvolution of OMV cross-protection
    description: >-
      Use post-vaccination human sera to identify gonococcal antigens
      recognized after 4CMenB vaccination, then test them individually and in
      combination for protection, to determine whether the cross-protective
      response can be reproduced by a defined subunit vaccine.
  evidence:
  - reference: PMID:42259835
    reference_title: "Pre-clinical efficacy of a candidate outer membrane vesicle gonococcal vaccine in comparison with 4CMenB."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Meningococcal vaccines MeNZB and 4CMenB (Bexsero), containing Neisseria meningitidis group B detergent-extracted outer membrane vesicles (dOMV), cross-protect against gonorrhoea with 31-59% effectiveness."
    explanation: >-
      Establishes that cross-protection is real but partial and attributed to
      the dOMV fraction rather than to identified antigens, which is precisely
      the gap this discussion poses.
notes: >-
  GeneReviews is not applicable: gonorrhea is an acquired bacterial infection,
  and a PubMed search returned no chapter. No human host gene causes the
  disease; host genetic contributions are limited to complement pathway
  deficiencies that predispose to dissemination, curated as a risk factor
  within the dissemination node rather than as causal genetics.

  Relationship to the treponematoses curated alongside this entry: gonorrhea
  and syphilis are the two classical bacterial STIs and share a strategy of
  antigenic variation - pilin and Opa variation here, TprK gene conversion in
  T. pallidum - but diverge completely on antimicrobial resistance. That
  contrast is modelled explicitly in the Sequential Loss of Antimicrobial
  Classes node.

  Deep-research caveat: the claude_code report attributed the 4CMenB
  cross-protection finding to PMID:32218555, which is in fact "Metal Levels,
  Genetic Instability, and Renal Markers in Electronic Waste Workers in
  Thailand" - a real paper on an entirely unrelated subject. The vaccine claims
  in this entry are instead cited to PMID:35642527, PMID:40334533, and
  PMID:38986746, each fetched and verified. 21 of the 22 PMIDs the report cited
  were real and on-topic; this was the single misattribution.

  Correction to an earlier version of this note. The first draft of this entry
  justified several omissions on the grounds that no cached source quoted the
  claim. Review showed that premise was wrong for a number of them: quotes
  supporting tenosynovitis, skin lesions, chronic pelvic pain, ectopic
  pregnancy, tubal infertility, Fitz-Hugh-Curtis perihepatitis, and the
  asymptomatic-infection pattern were all sitting in already-cached abstracts.
  Those are now curated with real evidence items. The lesson is recorded here
  rather than quietly fixed, because an omission rationale that misstates the
  evidence base is worse than a plain omission - it discourages the next
  curator from looking.

  Still deliberately not asserted, this time verified against the cache: the
  specific resistance determinants (penA mosaic alleles, mtrR/MtrCDE efflux,
  23S rRNA A2059G/C2611T, gyrA/parC QRDR mutations); the pilS recombination and
  slipped-strand mispairing mechanisms of antigenic variation; IL-17C-driven
  fallopian tube damage; and the UK Health Security Agency's 2025 approval of
  4CMenB for gonorrhea prevention. Each is described in the deep-research
  report but sourced there to full text or web pages rather than to citable
  abstracts. The fluoroquinolone and DNA gyrase nodes are omitted for the same
  reason: the abandonment of ciprofloxacin is real and well known, but no
  source cached here states it. Adding a dedicated antimicrobial-resistance
  reference would let those nodes be curated with conformance to
  bacterial_dna_topoisomerase_inhibition.

  Two phenotypes carry a free-text preferred_term with no term binding because
  HPO has no suitable term: Fitz-Hugh-Curtis perihepatitis, and asymptomatic
  infection (an absence of phenotype rather than a phenotypic abnormality).
  Ectopic pregnancy is unbound for a different reason - HP:0031456 exists and
  is correct, but is not reachable from the PhenotypeTerm enum root.

  Complement gene coverage. PMID:1554498 names C6, C7 and C8 as the inherited
  terminal-component deficiencies. C6 and C7 therefore carry that sentence as a
  gene-level anchor. C8 is not a single gene - the protein is a heterotrimer
  and inherited deficiency arises from either the alpha-gamma (C8A) or beta
  (C8B) subunit - so both subunit genes are curated with the naming sentence
  marked PARTIAL, because the source does not say which it means. C9 is curated
  on the class-level association only: that abstract does not name C9 anywhere,
  so no gene-level anchor is claimed for it.

  Frequency bands are asserted nowhere in this entry. The disseminated-infection
  percentages quoted from PMID:6415361 are proportions of DGI subgroups, not of
  patients with gonorrhea, so they support the phenotype association but cannot
  be mapped to a FrequencyEnum band.
references:
- reference: PMID:35489793
  title: "Neisseria gonorrhoeae physiology and pathogenesis."
  found_in:
  - Gonorrhea-deep-research-claude_code.md
  findings:
  - statement: >-
      The gonococcus adheres by type IV pili with PorB and Opa, and subverts
      complement-mediated killing by lipooligosaccharide sialylation together
      with a series of anti-phagocytic mechanisms - the immune-evasion core of
      this entry.
    supporting_text: "The gonococcus is able to subvert complement mediated killing and opsonisation by sialylation of its lipooligosaccharide and deploys a series of anti-phagocytic mechanisms."
- reference: PMID:35416971
  title: "Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines."
  found_in:
  - Gonorrhea-deep-research-claude_code.md
  findings:
  - statement: >-
      N. gonorrhoeae has developed resistance to all first-line recommended
      therapies, and the 2021 CDC guidelines consequently retreated to
      ceftriaxone 500 mg monotherapy.
    supporting_text: "Neisseria gonorrhoeae has developed resistance to all first-line recommended therapies, making gonococcal antimicrobial resistance a major public health concern given limited antibiotic options currently and an even smaller antimicrobial development pipeline."
clinical_trials: []
datasets: []
📚

References & Deep Research

References

2
PMID:35489793
Neisseria gonorrhoeae physiology and pathogenesis.
1 finding
The gonococcus adheres by type IV pili with PorB and Opa, and subverts complement-mediated killing by lipooligosaccharide sialylation together with a series of anti-phagocytic mechanisms - the immune-evasion core of this entry.
"The gonococcus is able to subvert complement mediated killing and opsonisation by sialylation of its lipooligosaccharide and deploys a series of anti-phagocytic mechanisms."
PMID:35416971
Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines.
1 finding
N. gonorrhoeae has developed resistance to all first-line recommended therapies, and the 2021 CDC guidelines consequently retreated to ceftriaxone 500 mg monotherapy.
"Neisseria gonorrhoeae has developed resistance to all first-line recommended therapies, making gonococcal antimicrobial resistance a major public health concern given limited antibiotic options currently and an even smaller antimicrobial development pipeline."

Deep Research

1
Claude Code ▸
Gonorrhea (*Neisseria gonorrhoeae* Infection) — Comprehensive Disease Characteristics Research Report
claude-haiku-4-5-20251001, claude-sonnet-5 54 citations 2026-08-08T14:26:49.565591

Gonorrhea (Neisseria gonorrhoeae Infection) — Comprehensive Disease Characteristics Research Report

1. Disease Information

Overview. Gonorrhea is a sexually transmitted bacterial infection caused by Neisseria gonorrhoeae, a Gram-negative, oxidase-positive, obligate human diplococcus. It is the second most common notifiable bacterial STI globally after chlamydia. Infection most commonly involves the mucosal epithelium of the urogenital tract (urethra, endocervix), but also infects the rectum, oropharynx, and conjunctiva, and can disseminate hematogenously to cause systemic disease (disseminated gonococcal infection, DGI). Untreated infection in women is a leading preventable cause of pelvic inflammatory disease (PID), tubal infertility, and ectopic pregnancy; in neonates it causes a sight-threatening ophthalmia neonatorum. N. gonorrhoeae is an obligate human pathogen with no other natural reservoir (PMID:35489793 — "Neisseria gonorrhoeae physiology and pathogenesis," comprehensive review, Adv Microb Physiol 2022).

Key identifiers: - MONDO: MONDO:0004277 (gonorrhea) - ICD-10-CM: A54 (Gonococcal infection), with subcodes A54.0 (lower genitourinary tract, no abscess), A54.1 (with periurethral/accessory gland abscess), A54.2 (pelviperitonitis and other genitourinary), A54.3 (eye), A54.4 (musculoskeletal), A54.5 (pharynx), A54.6 (anus/rectum), A54.8 (other), A54.9 (unspecified) - ICD-11 (MMS): 1A72 Gonococcal infection (with site-specific extension codes) - MeSH: D006069 (Gonorrhea); organism MeSH D009349 (Neisseria gonorrhoeae) - Orphanet: not a rare disease — no ORPHA code (common infectious STI, outside Orphanet's rare-disease scope) - NCBITaxon: NCBITaxon:485 (Neisseria gonorrhoeae)

Synonyms: "the clap," gonococcal infection, GC infection, gonococcal urethritis/cervicitis, gonococcemia (for disseminated disease).

Data provenance note: Most quantitative claims below derive from aggregated, disease-level public-health surveillance (CDC NNDSS/STI Surveillance reports, WHO global STI estimates) and case-series/cohort literature rather than individual EHR data, consistent with an infectious disease whose primary curation sources are population surveillance and clinical microbiology literature rather than genetic registries.

2. Etiology

Disease Causal Factor

The sole causal agent is infection with Neisseria gonorrhoeae. This is a purely infectious etiology — there is no genetic Mendelian basis for the disease itself (as distinct from host susceptibility modifiers, below). Transmission is via direct mucosal contact — genital, anorectal, or oropharyngeal sexual contact, or perinatal (mother-to-child) transmission during vaginal delivery.

Risk Factors

Environmental / behavioral risk factors (PMID:35489793; CDC STI Surveillance 2024): - Multiple or new sexual partners; unprotected (condomless) intercourse - Age 15–24 years (highest incidence band in most surveillance systems) - Men who have sex with men (MSM) — disproportionately high rectal/pharyngeal incidence - Prior gonorrhea or other STI (marker of ongoing exposure risk) - Sex work; high local community prevalence ("core group" transmission dynamics) - Illicit drug use, incarceration history, and inconsistent healthcare access (social determinants correlated with surveillance-reported incidence, CDC 2024 STI Surveillance Report, https://www.cdc.gov/sti-statistics/annual/index.html) - Co-infection with other STIs (chlamydia, syphilis, trichomoniasis) — shared risk-factor and mucosal-vulnerability profile

Genetic / host susceptibility risk factors: - Terminal complement pathway deficiencies (C5, C6, C7, C8, C9 and Factor I/Factor H of the alternative pathway) markedly predispose to disseminated and recurrent neisserial infection (both meningococcal and gonococcal), because the membrane attack complex (MAC) is the principal bactericidal mechanism against Neisseria in blood. A 2026 case report describes disseminated gonococcal infection due to a homozygous nonsense mutation in CFI (Factor I; p.Arg474) causing complete Factor I deficiency (PMID:41607490, PMC12829745). A separate case describes DGI in a man with compound-heterozygous C7 deficiency (PMC8021336). "Deficiencies of components of the alternative and terminal complement pathways have long been implicated in increasing the risk for neisserial infections." - Acquired complement deficiency (e.g., hypocomplementemic urticarial vasculitis, systemic lupus erythematosus with autoantibody-mediated complement consumption) has also been linked to extreme gonococcal susceptibility. - CEACAM receptor polymorphism/expression variability* on genital epithelium modulates strain-specific Opa-mediated adhesion/invasion susceptibility, though this is a variable host receptor-expression trait rather than a Mendelian risk allele (see Mechanism, §6).

Suggested ontology terms: HP:0005361 (Recurrent bacterial infections context — as HPO does not carry a "gonorrhea susceptibility" term per se, complement deficiency phenotypes are better captured via the causal gene); HGNC gene symbols for host modifier genes: CFI (hgnc:5394), C7 (hgnc:1346), C6 (hgnc:1339), C8A/C8B/C8G, C9 (hgnc:1358), CFH (hgnc:4883).

Protective Factors

  • Consistent condom use (mechanical barrier to mucosal contact)
  • Meningococcal serogroup B outer-membrane-vesicle (OMV) vaccines (4CMenB/Bexsero, and the earlier MeNZB) show cross-protective effectiveness against gonorrhea due to genomic/antigenic homology between N. meningitidis and N. gonorrhoeae — a landmark finding in STI vaccinology (see §13, Prevention).
  • No known protective human genetic alleles specific to gonococcal infection have been robustly established (unlike, e.g., sickle trait for malaria); complement sufficiency is simply the normal protective state, not a "protective variant."

Gene–Environment Interactions

The clearest gene–environment interaction is that an otherwise ordinary sexual exposure produces disseminated rather than localized infection specifically in hosts with terminal-complement-pathway lesions — i.e., the same environmental exposure (mucosal inoculation) yields a qualitatively different, more severe phenotype conditioned on host complement genotype (PMID:41607490; PMC8021336). This is the dominant, well-documented gene×environment axis for this disease; there is no evidence for polygenic susceptibility loci from GWAS at this time.

3. Phenotypes

Gonorrhea phenotypes are strongly site-dependent and frequently asymptomatic, which is itself an important epidemiological/clinical phenotype (~50% of women and up to 10% of men with urogenital infection are asymptomatic; pharyngeal and rectal infections are asymptomatic in the majority of cases; PMID:35489793 and CDC clinical guidance).

A. Uncomplicated urogenital infection

Phenotype HPO suggestion Notes
Urethral discharge (purulent, men) HP:0030128 (Urethral discharge) Onset 2–7 days post-exposure; classically profuse, yellow-green, purulent
Dysuria HP:0100518 Common in men; less prominent in women
Mucopurulent cervicitis / vaginal/cervical discharge HP:0000132 (Abnormal vaginal discharge) — best available fit Frequently subclinical in women
Intermenstrual bleeding HP:0100608 Cervicitis-associated
Testicular pain/epididymitis HP:0000796 (Testicular pain) / epididymitis phenotype Complication of male urethral infection

B. Extragenital/site-specific infection

Phenotype HPO suggestion Notes
Pharyngitis / sore throat HP:0025439 (Pharyngitis) Usually asymptomatic; oropharyngeal reservoir important for AMR spread via commensal Neisseria recombination
Proctitis (anorectal discharge, pain, tenesmus) HP:0002027 (Abdominal pain) is too broad — use free-text; SNOMED-preferred Common in receptive anal intercourse; often asymptomatic
Purulent conjunctivitis HP:0000534 (Purulent conjunctivitis) In neonates = ophthalmia neonatorum; in adults from autoinoculation

C. Ascending / complicated disease

Phenotype HPO suggestion Notes
Pelvic inflammatory disease (salpingitis) HP:0030014 (Pelvic inflammatory disease) if available, else free text ~10–15% of untreated women; N. gonorrhoeae accounts for roughly a third of PID cases (Illinois DPH; PMID:23007248)
Tubo-ovarian abscess — Severe PID sequela
Chronic pelvic pain HP:0030832 or free text Long-term PID sequela
Tubal factor infertility HP:0000789 (Infertility) Result of tubal scarring/occlusion following salpingitis
Ectopic pregnancy HP:0010935 (Ectopic pregnancy) Life-threatening PID sequela
Fitz-Hugh-Curtis syndrome (perihepatitis) — (right-upper-quadrant pain phenotype; "violin-string" adhesions between liver capsule and peritoneum) Extragenital spread of PID; PMID:6769152, PMC5755950
Epididymitis / prostatitis (men) — Ascending male infection

D. Disseminated gonococcal infection (DGI) — hematogenous spread (~0.5–3% of untreated infections)

Two classical clinical patterns (PMC11368578, PMC12701954): 1. Triad form: fever, dermatitis (pustular/vesiculopustular skin lesions on an erythematous base, typically acral), migratory polyarthralgia, and tenosynovitis (asymmetric, affecting wrists/fingers/knees/ankles) 2. Purulent monoarticular/oligoarticular septic arthritis — abrupt-onset asymmetric joint pain/swelling, often afebrile - Rare but severe: endocarditis, meningitis, osteomyelitis (PMC9602952 — gonococcal meningitis) - Strains from disseminated sites are disproportionately of the transparent (Opa-low) phenotype (90% in classic series), reflecting serum-resistance/immune-evasion phenotype selection for bloodstream survival

Suggested HP terms: HP:0001945 (Fever), HP:0100546 (Arthralgia), HP:0001369 (Arthritis), HP:0001386 (Joint swelling), HP:0100678 (Skin nodule)/pustular rash, HP:0100033 (Osteomyelitis), HP:0001297 (Stroke) N/A, HP:0001298 (Encephalopathy)/meningitis-related terms, HP:0030842 (Infective endocarditis).

E. Neonatal

Phenotype Notes
Gonococcal ophthalmia neonatorum Onset within first 5 days of life; marked bilateral purulent conjunctival discharge; historically a leading cause of infantile blindness before universal prophylaxis (PMID:8771523; NBK537599; NBK551572)

Quality of life impact

Asymptomatic and untreated infection drives ongoing transmission; symptomatic disease causes acute discomfort (dysuria, discharge, pelvic pain) and — critically — the downstream PID/infertility/ectopic pregnancy sequelae carry major reproductive-health and psychosocial quality-of-life burden in women of reproductive age. DGI-associated arthritis causes acute functional disability. No disease-specific validated QoL instrument was identified; general STI-related psychosocial burden is documented in the PID and infertility literature (PMID:12346974 — immunopathogenesis of PID and infertility).

4. Genetic/Molecular Information

Gonorrhea is not a human Mendelian disease — there is no human causal gene. The relevant "genetics" for this KB entry falls into two categories:

A. Host modifier/susceptibility genes (see §2)

  • CFI (Complement Factor I, hgnc:5394) — homozygous loss-of-function → complete Factor I deficiency → extreme susceptibility to disseminated/recurrent neisserial infection (PMID:41607490)
  • C7 (hgnc:1346), C6, C8A/C8B/C8G, C9 — terminal complement component deficiencies → impaired membrane attack complex formation → recurrent/disseminated neisserial disease (PMC8021336)
  • CFH — alternative pathway regulator; acquired/functional deficiency states similarly predispose

Relationship type for genetic annotation: MODIFIER/SUSCEPTIBILITY (not CAUSAL), since these genes govern severity/dissemination of an exogenous infection rather than causing the disease de novo.

B. Pathogen (bacterial) genetics — antimicrobial resistance determinants

These are not human genes but are central to modern gonorrhea molecular epidemiology and directly determine treatment mechanism/failure:

Gene Resistance phenotype Mechanism
penA (mosaic alleles, e.g., penA-237.001, penA-60.001) Reduced susceptibility / resistance to extended-spectrum cephalosporins (cefixime, ceftriaxone) Altered penicillin-binding protein 2 (PBP2) reduces β-lactam binding affinity (PMC9808317 — novel mosaic penA-237.001 causing ceftriaxone-resistant, multidrug-resistant N. gonorrhoeae, France 2022)
mtrR (promoter/coding mutations, mosaic mtrR-mtrCDE from N. meningitidis/N. lactamica) Increased efflux → macrolide (azithromycin) and other multidrug resistance Derepresses/upregulates the MtrC-MtrD-MtrE multidrug efflux pump (PMC6134098, PMC6083905 — Wadsworth et al., mBio 2018, PMID for related work; epistasis between mtrR and mosaic mtrD required for full azithromycin resistance)
ponA (P.A517G) Contributes to penicillin/cephalosporin resistance Altered PBP1
porB1b (penB) Reduced outer-membrane permeability Porin mutation reduces antibiotic influx
gyrA (S91F and related QRDR mutations) Fluoroquinolone (ciprofloxacin) resistance Altered DNA gyrase target; wild-type gyrA S91 used as a molecular susceptibility screen
parC Fluoroquinolone resistance (secondary target) Altered topoisomerase IV
23S rRNA (A2059G, C2611T) High-level azithromycin resistance Ribosomal target alteration

(PMC5628311 — comprehensive review "Antimicrobial resistance in Neisseria gonorrhoeae: history, molecular mechanisms and epidemiological aspects of an emerging global threat"; PMC9045316 — reliability of genetic markers for predicting ceftriaxone resistance globally.) The WHO in November 2021 flagged emerging ceftriaxone resistance/treatment-failure strains as a global AMR priority.

C. Epigenetic / chromosomal

No disease-relevant human epigenetic or chromosomal-abnormality literature applies (not a genetic disease). N. gonorrhoeae itself undergoes extensive phase and antigenic variation (Opa gene slipped-strand mispairing, pilin antigenic variation via recombination with silent pilS loci) — a bacterial "epigenetic-like" mechanism of immune evasion, distinct from human epigenetics (PMID:35489793).

Suggested ontology terms: GO:0046677 (response to antibiotic), GO:0015562 (efflux transmembrane transporter activity) for MtrCDE; CHEBI terms for antibiotics (§12).

5. Environmental Information

  • Infectious agent (primary etiology): Neisseria gonorrhoeae, NCBITaxon:485; Gram-negative diplococcus, family Neisseriaceae. Obligate human pathogen, no environmental or animal reservoir; transmitted exclusively via direct mucosal contact (sexual or perinatal).
  • Behavioral/lifestyle factors: unprotected sexual contact, multiple partners, sex work, substance use in sexual contexts (see §2 Risk Factors) — CDC/WHO surveillance sources.
  • No chemical/toxin/occupational environmental etiology applies; this is purely a sexually/perinatally transmitted bacterial infection.
  • Co-circulating pathogen environment: commensal Neisseria species (N. lactamica, N. cinerea, N. meningitidis, N. polysaccharea) in the oropharynx serve as a genetic reservoir for horizontal transfer of resistance determinants (mosaic mtr, penA alleles) into N. gonorrhoeae — the oropharynx is thus an important "environmental" site for AMR emergence (PMC6134098).

Suggested ontology terms: ECTO term for "exposure to sexually transmitted infectious agent" (no highly specific ECTO term for STI contact currently cataloged — would need OAK lookup); NCBITaxon:485 for the organism.

6. Mechanism / Pathophysiology

Causal chain overview

Mucosal exposure → colonization/adherence → epithelial invasion & transcytosis → local inflammatory response (neutrophil influx) → tissue damage / discharge → (if untreated) ascending/hematogenous spread → PID/DGI sequelae.

6.1 Colonization and adherence (initiating step)

  • Type IV pili (Tfp) mediate initial long-range attachment to mucosal epithelium and microcolony formation; pilin (PilE) undergoes high-frequency antigenic variation via recombination with silent pilS loci, and pilus retraction generates twitching motility (PMID:35489793).
  • Opacity-associated (Opa) proteins — up to 11 phase-variable paralogs — mediate tighter adhesion and, when engaged with host CEACAM family receptors (CEACAM1, CEACAM3, CEA/CEACAM5, CEACAM6), promote receptor-mediated invasion/transcytosis of epithelial cells (PMID:21204865 — Opa proteins and CEACAMs review, FEMS Microbiol Rev). Differential CEACAM expression along the female reproductive tract determines the outcome (colonization vs. invasion vs. clearance) of infection at different anatomic sites (journals.asm.org/iai.00092-18). Notably, CEACAM engagement is not strictly required — Opa+ gonococci can adhere to/invade genital epithelial cells via heparan sulfate proteoglycans (HSPG) independent of CEACAM (PMID:11580753).
  • Porin (PorB) also contributes to adherence and, upon translocation into host mitochondrial and plasma membranes, modulates host-cell apoptosis and calcium flux.

6.2 Immune evasion (central pathogenic strategy)

  • Lipooligosaccharide (LOS) sialylation, using host-derived CMP-NANA, masks LOS and blocks classical/alternative complement pathway activation and opsonophagocytic killing — a major serum-resistance mechanism.
  • Anti-phagocytic mechanisms allow intracellular survival within neutrophils via direct interference with the oxidative burst (NADPH oxidase assembly) and delayed phagolysosome maturation, permitting the organism to persist within — rather than be cleared by — the very cells recruited to fight it (PMC4154863 — "Global Analysis of Neutrophil Responses to Neisseria gonorrhoeae Reveals a Self-Propagating Inflammatory Program").
  • Antigenic and phase variation (Opa, pilin, LOS) generates within-host antigenic diversity that impedes adaptive immune clearance and explains the striking absence of protective natural immunity/reinfection resistance.
  • Macrophage polarization to an M2 (anti-inflammatory/less microbicidal) phenotype by gonococcal infection has been demonstrated as an additional subversion strategy (PMC4488386).

6.3 Inflammatory tissue damage (downstream of colonization)

  • Rather than direct cytotoxicity, gonococcal pathology is substantially immunopathological: sustained neutrophil influx that fails to clear the organism instead releases antimicrobial products (reactive oxygen species, proteases, defensins) that damage host mucosa — producing the purulent discharge that is the clinical hallmark of infection (PMID:35489793, PMC4154863).
  • In the fallopian tube, IL-17C has been identified as a driver of damaging inflammation during ex vivo N. gonorrhoeae infection of human Fallopian tube explants, contributing to ciliated-cell sloughing, epithelial exfoliation, tubal scarring, and eventual occlusion (Nature Communications 2024, DOI:10.1038/s41467-024-48141-3; PMC11069574).
  • Progressive fallopian tube damage → PID → chronic pelvic pain, tubal-factor infertility, ectopic pregnancy (immunopathogenesis reviewed PMID:12346974).

6.4 Dissemination (hematogenous spread → DGI)

  • Strains with the transparent (Opa-low) phenotype and LOS sialylation/serum-resistance are preferentially recovered from blood/synovial fluid in DGI, reflecting selection for bloodstream survival over epithelial adherence.
  • Host terminal complement pathway deficiency removes the primary bactericidal barrier to bacteremia, explaining recurrent/disseminated presentations in affected individuals (§2, §4).
  • Disseminated organisms seed skin (pustular dermatitis), joints/tendon sheaths (septic arthritis/tenosynovitis), and rarely heart valves, meninges, or bone.

Cell types and processes involved

  • Cell types: genital/cervical/urethral/rectal/pharyngeal/conjunctival columnar and stratified epithelial cells (site-specific tropism), neutrophils (CL:0000775), macrophages (CL:0000235), fallopian tube ciliated epithelial cells (CL:1000272 or similar), synoviocytes (DGI arthritis).
  • Suggested GO biological process terms: GO:0007155 (cell adhesion), GO:0044409 (entry into host), GO:0052255 (modulation by symbiont of host innate immune response), GO:0006956 (complement activation) — as a target of evasion, GO:0002532 (production of molecular mediator involved in inflammatory response), GO:0043312 (neutrophil degranulation).
  • Suggested UBERON terms: UBERON:0000056 (ureter — n/a), UBERON:0000057 (urethra), UBERON:0000995 (uterine cervix), UBERON:0003889 (fallopian tube), UBERON:0004908 (oropharynx), UBERON:0001358 (cerebrospinal fluid — meningitis), UBERON:0002370 (thymus — n/a); UBERON:0000966 (retina — n/a) — more precisely UBERON:0001759 (conjunctiva) for ophthalmia neonatorum, UBERON:0001474 (bone element) for osteomyelitis, UBERON:0000982 (synovial fluid)/UBERON:0001466 (synovial joint) for DGI arthritis.
  • Suggested CHEBI terms (host/pathogen molecules): CHEBI:24433 (lipooligosaccharide — approximate; LOS is not a single well-defined CHEBI entity but relevant chemical class), CHEBI for sialic acid (CHEBI:26667, N-acetylneuraminic acid).

7. Anatomical Structures Affected

Organ/system level: - Primary: male and female lower genitourinary tract (urethra, endocervix, Skene's/Bartholin's glands), rectum, pharynx, conjunctiva - Secondary (ascending/complications): fallopian tubes, ovaries, peritoneum (pelviperitonitis), epididymis, prostate, liver capsule (Fitz-Hugh-Curtis) - Disseminated: skin, synovial joints/tendon sheaths, heart valves (rare endocarditis), meninges (rare meningitis), bone (rare osteomyelitis) - Body systems: reproductive system, integumentary system, musculoskeletal system, ocular system, and rarely cardiovascular and central nervous systems

Tissue/cell level: columnar/transitional epithelium (urethra, endocervix, rectum), stratified squamous epithelium (vagina — relatively resistant to colonization compared to columnar epithelium sites), ciliated fallopian tube epithelium, synovium, conjunctival epithelium.

Subcellular level: phagosome/phagolysosome (site of intracellular neutrophil survival), plasma membrane and mitochondrial membrane (PorB translocation), outer membrane (LOS/Opa/pilin expression).

Suggested UBERON terms: UBERON:0000057 (urethra), UBERON:0000995 (uterine cervix), UBERON:0003889 (fallopian tube/oviduct), UBERON:0001350 (coelomic cavity/peritoneum — approx UBERON:0002358 for peritoneal cavity), UBERON:0004908 (oropharynx), UBERON:0001759 (conjunctiva), UBERON:0001466 (synovial joint), UBERON:0002107 (liver — Fitz-Hugh-Curtis), UBERON:0001474 (bone element).

8. Temporal Development

Onset: - Incubation period: typically 2–7 days post-exposure for symptomatic urethral infection in men (classic range); cervical/rectal/pharyngeal infection incubation is less well defined and often clinically silent. - Onset pattern: acute for symptomatic urogenital disease; frequently asymptomatic/subclinical at cervical, rectal, and pharyngeal sites, which is itself the key epidemiologic driver of ongoing transmission. - Neonatal ophthalmia neonatorum: onset within the first 5 days of life, reflecting intrapartum exposure timing.

Progression: - Untreated urogenital infection may spontaneously clear over weeks-to-months in a fraction of cases, but a substantial proportion progresses to ascending infection. - PID typically develops days to weeks after untreated cervical infection; roughly 10–15% of women with untreated gonorrhea (or chlamydia) develop PID. - DGI develops in an estimated 0.5–3% of untreated gonococcal infections, usually within days to a few weeks of the primary mucosal infection, and can present acutely (arthritis-dermatitis syndrome, days) or with the purulent-arthritis pattern. - Disease course is not chronic/progressive in the classic autoimmune-disease sense; it is an acute-to-subacute bacterial infection whose "chronicity" manifests as (a) persistent untreated colonization enabling transmission and (b) fibrotic/scarring sequelae (tubal occlusion, adhesions) that are permanent once established, even after microbiological cure.

Patterns: - No spontaneous remission-relapse pattern in the classic sense; recurrence is virtually always reinfection from an untreated/new partner rather than true relapse, given lack of durable protective immunity and high antigenic variability. - Critical intervention window: early antibiotic treatment before ascending spread prevents essentially all PID/tubal-damage sequelae — this is the central rationale for STI screening programs.

9. Inheritance and Population

Not a genetically inherited disease — inheritance-pattern fields (AD/AR/X-linked, penetrance, expressivity, anticipation, founder effects, consanguinity, carrier frequency) are not applicable to gonorrhea itself. (They would be applicable only to the rare host complement-deficiency modifier genes noted in §2/§4, which follow autosomal recessive inheritance for the classic terminal-complement-component deficiencies.)

Epidemiology: - Global incidence (WHO, 2020 estimate): approximately 82.4 million new infections among adults aged 15–49 worldwide in 2020 (WHO fact sheet, https://www.who.int/news-room/fact-sheets/detail/gonorrhoea-(neisseria-gonorrhoeae-infection); WHO Nov 2021 AMR surveillance report). It is the second most common bacterial STI after chlamydia. - United States (CDC 2024 provisional surveillance): Gonorrhea cases declined for a third consecutive year, down ~10% from 2023; combined chlamydia/gonorrhea/syphilis cases fell 9% from 2023. However, total 2024 U.S. STIs (all types) still exceeded 2.2 million reported cases, and overall STI burden remains 13% higher than a decade prior (CDC 2024 STI Surveillance report, https://www.cdc.gov/sti-statistics/annual/index.html; https://www.hiv.gov/blog/cdc-releases-2024-national-sti-data). - Possible contributor to the recent U.S. decline: expanded meningococcal B vaccine use in college-age/high-risk adults, given documented cross-protection against gonorrhea (see §13). - Disseminated gonococcal infection (DGI) surveillance in the U.S., 2020–2022 (PMC9751791, "Mind the Clap").

Population demographics: - Age distribution: highest incidence in 15–24-year-olds, reflecting sexual-activity patterns and behavioral/biological (cervical ectopy) susceptibility in young women. - Sex/behavioral group distribution: disproportionately high burden among men who have sex with men (MSM), particularly for rectal and pharyngeal infection; also elevated among sex workers, transgender women, and adolescents/young adults in high-burden settings (WHO fact sheet). - Geographic distribution: globally endemic, with the highest burden in the WHO African and Western Pacific regions per global estimates; substantial regional variation in antimicrobial-resistance prevalence — e.g., high tetracycline resistance prevalence across 22 European countries in 2024 surveillance (PMC12811707). - Racial/ethnic and state-level U.S. breakdowns for 2024 were not yet released by CDC at time of the 2024 provisional report due to ongoing surveillance-system updates (Healthbeat, https://www.healthbeat.org/2025/10/07/sti-chlamydia-gonorrhea-syphilis-cdc-data/).

Suggested ontology term: NCBITaxon:9606 (Homo sapiens, sole natural host).

10. Diagnostics

Clinical/laboratory tests: - Nucleic acid amplification testing (NAAT) is the current diagnostic standard of care — highly sensitive and specific for genital specimens (urine, urethral/endocervical/vaginal swabs), and validated for extragenital (rectal, oropharyngeal) specimens where it substantially outperforms culture (PMID:20335410; PMID:18520976; PMC1871692 "Nucleic Acid Amplification Testing for Neisseria gonorrhoeae: An Ongoing Challenge"; PMC8769746 multicenter NAAT comparison for rectal/oropharyngeal specimens). Commercial platforms include Gen-Probe APTIMA COMBO 2/APTIMA GC, Roche COBAS Amplicor/4800 CT/NG, BD ProbeTec, Abbott RealTime CT/NG (PMC3187337). - Important caveat: false-positive NAAT results can occur due to horizontal genetic exchange between N. gonorrhoeae and commensal Neisseria species sharing amplified target sequences — an important diagnostic-interpretation caveat, especially at pharyngeal sites. - Culture (Thayer-Martin or modified selective media) remains essential for antimicrobial susceptibility testing and outbreak/AMR surveillance, despite lower sensitivity than NAAT, particularly for extragenital sites. - Gram stain of urethral discharge in symptomatic men (intracellular Gram-negative diplococci within neutrophils) remains a rapid point-of-care diagnostic with high sensitivity/specificity in that specific clinical context, though far less reliable for cervical, rectal, or pharyngeal specimens. - Molecular AMR prediction: genotypic assays targeting gyrA (ciprofloxacin susceptibility screening via detection of wild-type S91), and increasingly whole-genome-sequencing-based prediction of penA/mtrR/23S rRNA resistance markers, though reliability of genotype-based ceftriaxone-resistance prediction remains imperfect globally (PMC9045316).

Genetic testing: Not applicable in the human-genetics sense (no causal human gene); pathogen molecular typing (NG-MAST, NG-STAR, whole-genome sequencing) is used for surveillance and AMR-marker detection rather than "genetic testing" of the patient.

Omics-based diagnostics: Whole-genome sequencing of clinical isolates is increasingly used for AMR surveillance and outbreak/transmission-cluster tracking (PMC8442004, "Recent advances in understanding and combatting Neisseria gonorrhoeae: a genomic perspective") — this is pathogen genomics, not host omics.

Clinical criteria / differential diagnosis: Urethritis/cervicitis differential includes Chlamydia trachomatis (frequent co-infection — CDC recommends empiric doxycycline co-treatment when chlamydia is not excluded), Mycoplasma genitalium, Trichomonas vaginalis, and non-infectious urethritis/cervicitis. DGI arthritis-dermatitis syndrome differential includes reactive arthritis, viral exanthem-associated arthritis, and other causes of septic arthritis.

Screening: CDC/USPSTF recommend annual gonorrhea (and chlamydia) screening for sexually active women <25 years and older women with risk factors, and for MSM at exposed anatomic sites (urogenital, rectal, pharyngeal) at least annually (more frequently for high-risk individuals). Universal ocular prophylaxis at birth (erythromycin ointment historically; topical agents per current guidance) remains recommended in the U.S. for prevention of ophthalmia neonatorum (NBK537599 — USPSTF reaffirmation evidence review).

Suggested LOINC/ontology: LOINC panels exist for N. gonorrhoeae NAAT (e.g., LOINC:43304-5 and site-specific variants); SNOMED CT for clinical/pathology findings.

11. Outcome/Prognosis

  • Mortality: Direct mortality from uncomplicated gonorrhea is essentially negligible with treatment; mortality is confined to rare severe DGI complications (endocarditis, meningitis) and to indirect mortality via ectopic pregnancy, which remains a life-threatening PID sequela.
  • Morbidity: The dominant morbidity burden is reproductive: an estimated 10–15% of women with untreated gonorrhea/chlamydia develop PID; PID prevalence among reproductive-age U.S. women is estimated at 4.1%, with N. gonorrhoeae implicated in roughly a third of cases (Illinois DPH; PMID:23007248). PID sequelae include chronic pelvic pain, tubal-factor infertility, and ectopic pregnancy.
  • Recovery potential: With prompt, effective antibiotic treatment, uncomplicated mucosal infection resolves completely with no long-term sequelae. Once tubal scarring/occlusion has occurred, however, infertility and elevated ectopic-pregnancy risk are not reversible by subsequent antibiotic treatment — underscoring the importance of early detection given the high asymptomatic-carriage rate.
  • DGI outcomes: With appropriate IV/IM antibiotic therapy, DGI arthritis-dermatitis syndrome and septic arthritis generally resolve without permanent joint damage if treated promptly; delayed treatment risks joint destruction from septic arthritis and, rarely, endocarditis/meningitis-related mortality/morbidity.
  • Prognostic factors: delay to treatment (strongest driver of PID/tubal-damage risk), host complement status (drives DGI risk), and infecting strain's antimicrobial susceptibility profile (treatment-failure risk with resistant strains is an emerging and consequential prognostic factor per WHO AMR surveillance, 2021).
  • HIV interaction: gonococcal (especially rectal) co-infection is independently associated with substantially increased HIV acquisition and transmission risk — a 2–5-fold increase in susceptibility attributed to mucosal epithelial damage and increased local HIV target-cell recruitment/viral shedding (PMC5779692 — N. gonorrhoeae co-infection exacerbates vaginal HIV shedding in a humanized mouse model; academic.oup.com/ofid — repeated rectal gonorrhea independently associated with incident HIV infection risk in MSM). This materially worsens long-term prognosis in co-infected populations by amplifying HIV epidemic spread.

12. Treatment

Current first-line pharmacotherapy (CDC 2021 STI Treatment Guidelines, updated 2020 recommendations; PMID:35416971, academic.oup.com/cid supplement): - Ceftriaxone 500 mg IM single dose (uncomplicated infection of any anatomic site — genital, rectal, pharyngeal) — increased to 1 g IM for patients weighing ≥150 kg (300 lb). - This replaced the prior dual-therapy regimen of ceftriaxone 250 mg IM + azithromycin 1 g PO, reflecting rising azithromycin resistance concerns and evidence that single-agent ceftriaxone is highly effective, reducing selective pressure for macrolide resistance. - Co-treatment for chlamydia: if chlamydial co-infection has not been excluded, add doxycycline 100 mg PO BID × 7 days. - Cephalosporin-allergic patients: limited alternatives exist; no recommended alternative regimen for pharyngeal infection specifically, reflecting the therapeutic difficulty of that site; oral cefixime 800 mg single dose may be used for expedited partner therapy (EPT) when injectable ceftriaxone is not feasible, though it is not preferred given lower efficacy at some anatomic sites and resistance concerns. - DGI (disseminated disease): requires initial parenteral ceftriaxone (typically 1 g IV/IM daily) for a longer course, often transitioning to oral therapy after clinical improvement, per site-specific severity (arthritis, meningitis, endocarditis regimens differ in duration/dose). - Ophthalmia neonatorum: ceftriaxone (single IM/IV dose, weight-based) plus saline eye irrigation; prevention via universal neonatal ocular prophylaxis remains standard of care.

Pharmacogenomics: No clinically significant host pharmacogenomic determinants of gonorrhea drug response have been established (unlike, e.g., HLA-linked hypersensitivity syndromes for other drugs); the dominant "resistance genomics" concern is pathogen genotype (§4/§9), not host genotype.

Advanced/experimental therapeutics: No gene therapy, cell therapy, RNA-based therapy, or targeted/immunotherapy applies to this bacterial infection; management is exclusively antimicrobial.

Surgical/interventional: Reserved for complications — e.g., drainage of tubo-ovarian abscess, arthrocentesis/surgical debridement for severe septic arthritis, laparoscopy for Fitz-Hugh-Curtis adhesion lysis/diagnosis.

Supportive care: symptomatic management of pain/discharge; partner notification and treatment (expedited partner therapy, EPT) is a core component of clinical management to prevent reinfection and interrupt transmission chains.

Treatment outcomes / resistance concerns: The central emerging treatment-outcome issue is antimicrobial resistance, with documented multidrug-resistant and ceftriaxone-resistant strains (mosaic penA alleles) reported globally, including in France (2022, PMC9808317) and elsewhere, prompting WHO to designate gonococcal AMR a global health priority (WHO, Nov 2021) and driving intensified interest in non-antibiotic prevention strategies (vaccines, see §13).

Suggested NCIT terms: - NCIT:C15986 (Pharmacotherapy) — generic action for the antibiotic regimens - NCIT:C15632 (Chemotherapy) — not applicable here (antibacterial, not chemo) - Therapeutic agents (CHEBI): ceftriaxone (CHEBI:3508), azithromycin (CHEBI:2955), doxycycline (CHEBI:50845), cefixime (CHEBI:475130), ciprofloxacin (CHEBI:100241) — verify exact CHEBI IDs via OAK lookup before curation. - NCIT:C15329 (Surgical Procedure) for abscess drainage/laparoscopy in complicated PID.

13. Prevention

Primary prevention: - Barrier contraception (consistent, correct condom use) remains the principal behavioral primary-prevention measure. - Behavioral risk-reduction counseling and partner-reduction strategies (CDC/WHO public health guidance). - Vaccination (major recent development): Meningococcal serogroup B outer-membrane-vesicle (OMV) vaccines — 4CMenB (Bexsero) and the earlier New Zealand MeNZB — demonstrate significant cross-protective effectiveness against gonorrhea, attributed to antigenic homology between N. meningitidis and N. gonorrhoeae OMV components: - 4CMenB induces cross-species protection against N. gonorrhoeae in preclinical models (PMC7748408/PMID:32218555, npj Vaccines). - A matched cohort study in Southern California found real-world protective effectiveness (PMID:35642527). - Multiple 2025 systematic reviews/meta-analyses confirm statistically significant reductions in gonorrhea incidence among OMV-MenB vaccine recipients versus unvaccinated or non-OMV-vaccinated comparators, with effectiveness estimates in the range of 23–46%, and one case-control estimate (using chlamydia as a negative control) of ~31% (PMID:40334533; academic.oup.com/jid/article/231/1/61; PMID:38986746). - Policy uptake: in August 2025, the UK Health Security Agency approved 4CMenB use specifically to prevent gonorrhea in high-risk populations, including individuals with repeat infections and MSM — the first national policy explicitly using a meningococcal vaccine for gonorrhea prevention. - Purpose-built gonococcal vaccines are in active development: GSK's investigational N. gonorrhoeae GMMA (Generalized Modules for Membrane Antigens) vaccine is in a Phase 1/2 clinical trial (NCT05630859); preclinical native-OMV candidate vaccines engineered from gonococcal strains (with lpxL1/rmp deletions to reduce reactogenicity) show promise compared to 4CMenB in animal models (npj Vaccines 2026, PMID:42259835). WHO identified gonorrhea vaccine development as a global priority in 2024, driven by rising antimicrobial resistance. - Caveat: breakthrough rectal N. gonorrhoeae infections after meningococcal B vaccination have been reported, underscoring that current cross-protection is partial, not sterilizing (academic.oup.com/ofid/article/11/11/ofae562).

Secondary prevention (screening/early detection): - Routine annual NAAT-based screening of sexually active women <25 and higher-risk older women, and of MSM at all exposed anatomic sites (§10). - Universal neonatal ocular prophylaxis at birth remains a longstanding, evidence-supported secondary/primary prevention measure against ophthalmia neonatorum (USPSTF reaffirmation, NBK537599).

Tertiary prevention: Prompt treatment of diagnosed infection and of PID specifically to minimize progression to tubal damage/infertility/ectopic pregnancy; partner treatment (EPT) to prevent reinfection cycles.

Public health interventions: Partner notification/contact tracing programs, expedited partner therapy (EPT) policies, community-based STI testing outreach in high-prevalence "core group" populations, and enhanced AMR surveillance (WHO Gonococcal Antimicrobial Surveillance Programme, GASP) to guide empiric treatment recommendations as resistance patterns shift regionally.

Prophylaxis: No pre-exposure chemoprophylaxis is currently recommended for gonorrhea specifically (in contrast to doxycycline post-exposure prophylaxis, "doxy-PEP," which is increasingly used for chlamydia/syphilis prevention in high-risk MSM populations but has shown limited/inconsistent efficacy specifically against gonorrhea due to existing tetracycline-class resistance).

14. Other Species / Natural Disease

N. gonorrhoeae is a strict human-obligate pathogen with no natural non-human reservoir or naturally occurring disease in animals. This is a defining biological feature of the organism (unlike, e.g., zoonotic pathogens). - Taxonomy: NCBITaxon:485 (Neisseria gonorrhoeae); genus Neisseria (NCBITaxon:482) includes related pathogenic species N. meningitidis (NCBITaxon:487) and commensal species (N. lactamica, NCBITaxon:489; N. cinerea; N. polysaccharea) that participate in horizontal AMR gene transfer (§4, §5). - No breed-specific (VBO) relevance — not an animal disease. - No natural veterinary disease is recognized; N. gonorrhoeae does not naturally infect animals, so there is no OMIA entry or veterinary comparative-pathology literature analogous to a zoonosis. - Zoonotic potential: none — transmission is exclusively human-to-human (sexual or perinatal).

15. Model Organisms

Because N. gonorrhoeae is a strict human pathogen, animal models require special adaptation and none fully recapitulates human disease; each has defined utility and limitations.

Female mouse model (the dominant experimental system): - Wild-type mice are naturally resistant to gonococcal genital colonization (PMID:2506350, "Resistance of mice to genital infection with Neisseria gonorrhoeae"). - Estradiol-treated female mice serve as surrogate hosts: exogenous 17β-estradiol treatment (which thins the vaginal epithelium toward a more human-cervix-like columnar-favorable state and suppresses normal murine flora) permits reproducible lower-genital-tract colonization that recapitulates many features of human infection, including innate immune responses and gonococcal genetic requirements for in vivo fitness (PMID:21747807, "Estradiol-Treated Female Mice as Surrogate Hosts for Neisseria gonorrhoeae Genital Tract Infections," Front Microbiol 2011; developed principally by the Jerse laboratory, Uniformed Services University). - This model has been used extensively for antimicrobial efficacy testing (e.g., auranofin efficacy against gonococcal genital infection, PMC9022871) and for vaccine preclinical efficacy testing (e.g., OMV candidate vaccine vs. 4CMenB comparison, npj Vaccines 2026). - Limitations: requires exogenous hormone manipulation (not physiologic estrus), does not reproduce upper-tract ascension/PID or DGI pathology, and murine complement/CEACAM/receptor biology differs from human, limiting some immune-evasion and adhesion-mechanism studies to in vitro human-cell systems. - Review: PMID:28886683, "Neisseria gonorrhoeae: Drug Resistance, Mouse Models, and Vaccine Development," Annu Rev Microbiol 2017.

Other model systems: - Human ex vivo Fallopian tube organ culture — used to directly study PID-relevant tubal damage mechanisms (e.g., the IL-17C inflammatory-damage studies, PMC11069574/PMC (bioRxiv) 2022) — arguably the most human-fidelity model for upper-tract pathology, since no rodent naturally recapitulates fallopian tube disease. - Human cell-line/primary epithelial cell culture (cervical, urethral epithelial lines; polarized epithelial monolayers) — used extensively for adhesion/invasion/Opa-CEACAM mechanism studies (§6). - Humanized (CD34+ engrafted) mouse models — used specifically to study N. gonorrhoeae–HIV co-infection interactions in a system with human immune cells, demonstrating exacerbated vaginal HIV shedding during gonococcal co-infection (PMC5779692). - Zebrafish, Drosophila, C. elegans, yeast: no established gonorrhea disease models identified in the literature searched — N. gonorrhoeae research relies predominantly on the estradiol mouse model and human ex vivo/cell-culture systems given the organism's human-restricted tropism.

Suggested model-organism ontology terms: NCBITaxon:10090 (Mus musculus), model type "induced infection model" (hormone-primed genital colonization); MGI resources for background mouse strain records; Cellosaurus IDs for relevant human epithelial cell lines used in adhesion/invasion assays (e.g., ME-180, HEC-1-B cervical lines — verify via literature before citing specific Cellosaurus accessions).

Summary of Key Ontology Term Suggestions for KB Curation

Category Suggested terms
MONDO MONDO:0004277 (gonorrhea)
NCBITaxon (pathogen) NCBITaxon:485 (N. gonorrhoeae)
HGNC (host modifier genes) hgnc:5394 (CFI), hgnc:1346 (C7), hgnc:1358 (C9), hgnc:4883 (CFH)
HP (phenotypes) HP:0030128 (urethral discharge), HP:0100518 (dysuria), HP:0000534 (purulent conjunctivitis), HP:0001945 (fever), HP:0100546 (arthralgia), HP:0001369 (arthritis), HP:0000789 (infertility), HP:0010935 (ectopic pregnancy)
GO (biological process) GO:0007155 (cell adhesion), GO:0044409 (entry into host), GO:0052255 (modulation by symbiont of host innate immune response), GO:0043312 (neutrophil degranulation)
CL (cell types) CL:0000775 (neutrophil), CL:0000235 (macrophage), ciliated fallopian-tube epithelial cell
UBERON UBERON:0000057 (urethra), UBERON:0000995 (cervix), UBERON:0003889 (fallopian tube), UBERON:0004908 (oropharynx), UBERON:0001759 (conjunctiva), UBERON:0001466 (synovial joint)
CHEBI (drugs) ceftriaxone, azithromycin, doxycycline, cefixime, ciprofloxacin (verify exact CURIEs via OAK)
NCIT (treatment) NCIT:C15986 (Pharmacotherapy), NCIT:C15329 (Surgical Procedure)

Sources