Granuloma Inguinale (Donovanosis): Comprehensive Disease Profile

Disease: Granuloma Inguinale (Donovanosis) · MONDO: MONDO:0005777 · Category: Infectious Disease Report date: 2026-09-25 · Evidence base: Human clinical studies, case reports/series, phylogenetic and ultrastructural studies, and management guidelines (primarily aggregated disease-level literature, not individual EHR).

Summary (Answer to the Research Question)

Granuloma inguinale (donovanosis) is a chronic, slowly progressive, mildly contagious sexually transmitted bacterial infection that produces characteristic beefy-red, friable, readily bleeding genital/inguinal ulcers. It is caused by the intracellular Gram-negative bacillus Klebsiella granulomatis (formerly Calymmatobacterium granulomatis). The organism parasitizes tissue macrophages/histiocytes, driving a granulomatous, plasma-cell–rich inflammatory response with overlying pseudoepitheliomatous hyperplasia; the intracytoplasmic bacteria are visible as pathognomonic Donovan bodies. Diagnosis rests on cytology/histology (Donovan bodies) and, increasingly, PCR, because the organism is difficult to culture. Azithromycin is first-line therapy, with cure the norm. It is a rare, geographically restricted disease (endemic foci in Papua New Guinea, southern Africa, India, Brazil, and formerly among Aboriginal Australians) that is declining toward eradication, and it is an established cofactor for HIV-1 acquisition/transmission. As a purely infectious disease it has no human causal gene, no Mendelian inheritance, and no established animal model; several template sections (host genetics, model organisms, germline variants) are therefore Not Applicable.

1. Disease Information

• Overview: A chronic ulcerative bacterial STI of the genital and inguinal region. Genital papules appear after a ~50-day incubation and evolve into progressively enlarging, painless, friable ulcers with a beefy-red granulation base that bleed on contact. Course is indolent and progressive without treatment; healing occurs with antibiotics.
• Key identifiers:
• MONDO: MONDO:0005777
• ICD-10: A58 (Granuloma inguinale); ICD-11: 1A76 (Granuloma inguinale)
• MeSH: D006099 "Granuloma Inguinale"
• SNOMED CT: 5006005 (Granuloma inguinale)
• OMIM / Orphanet: Not applicable as a Mendelian disorder (infectious disease; no OMIM phenotype entry). Orphanet does not list it as a rare genetic disease.
• Causative organism NCBI Taxonomy: Klebsiella granulomatis (txid280) / Calymmatobacterium granulomatis.
• Synonyms / alternative names: Donovanosis; granuloma venereum; granuloma inguinale tropicum; "serpiginous ulcer" (historical); ulcerating granuloma of the pudenda. (Note: distinct from granuloma inguinale tropicum/LGV historically confused terminology.)
• Information source: Aggregated disease-level literature (guidelines, reviews, clinical case series), not individual-patient EHR.

Evidence: 41016613 — "Donovanosis usually causes genital ulcers with a distinct clinical appearance… The causative organism is a gram-negative bacillus, Calymmatobacterium granulomatis." 42486240 (historical review).

2. Etiology

• Causal factor — infectious: Klebsiella granulomatis (formerly Calymmatobacterium granulomatis), an encapsulated, intracellular Gram-negative bacillus of family Enterobacteriaceae. Transmission is predominantly sexual (genital, and via ano-receptive/oro-genital contact); low infectivity, with autoinoculation contributing to spread. There is no genetic/heritable cause.
• Risk factors (environmental/behavioral): residence in or travel to endemic areas; multiple sexual partners; low socioeconomic status/poor access to care; male sex and young adult age (peak in sexually active adults, ~15–40 y); poor genital hygiene; possibly fecal contamination/anal exposure. No genetic susceptibility loci have been identified.
• Protective factors: condom use, partner notification/treatment, sexual abstinence during treatment, early antibiotic therapy, and general STI-control/health-education programs. No genetic protective variants (Not Applicable).
• Gene–environment interactions: Not applicable to host genetics. The clinically relevant interaction is comorbidity with HIV, where immunodeficiency prolongs/worsens disease and requires extended therapy.

Evidence: 10555350; 10482295; 22239475 — reclassification and phylogeny; 41016613 — Gram-negative bacillus, nomenclature debate.

3. Phenotypes

Primary phenotype — chronic genital ulcer (HP:0000163 region; HP:0200035 "Genital ulcers"): - Type: clinical sign / physical manifestation (mucocutaneous ulceration). - Characteristics: adult-onset; typically painless or minimally painful; beefy-red, granulomatous, friable base that bleeds readily on contact; slowly progressive/enlarging; chronic (weeks–months). In a Durban series, ulcers persisted >28 days in ~55% of men and ~46% of women. - Four recognized morphologic subtypes: ulcerogranulomatous (most common), hypertrophic/verrucous, necrotic (deep, foul-smelling, destructive), and sclerotic/cicatricial (fibrotic).

Associated signs/complications: - Pseudobuboes — subcutaneous inguinal granulomas mimicking lymphadenopathy (HP:0002716 lymphadenopathy — note: true lymphadenitis is usually absent). - Genital/vulval swelling → elephantiasis (HP:0100820) from lymphatic obstruction (chronic cases). - Tissue destruction/mutilation, scarring, stricture; genital lymphedema. - Secondary squamous cell carcinoma (HP:0002860) in long-standing lesions (rare).

Frequency: Ulcerogranulomatous form predominates (>90% of lesions in series). Quality-of-life impact: substantial physical disability, disfigurement, sexual/urinary dysfunction, and psychological distress/stigma, particularly with elephantiasis or mutilating disease; formal EQ-5D/SF-36 data are not available for this rare disease. Stigma is amplified by sensationalist media: reports of a "flesh-eating infection donovanosis" are false and "only leading to hyperbole and increased stigma among those infected" (41016613).

Pregnancy & special populations: In a Durban series of 123 women, 42% were pregnant; in ~85% donovanosis had no effect on pregnancy outcome and there was no evidence of congenital disease in neonates (8735293), though extensive vulval lesions can complicate delivery. Erythromycin is the preferred agent in pregnancy. Disease behaves similarly in HIV-positive and HIV-negative women, though healing may be slower with advanced immunodeficiency.

Evidence: 26882914 / 21097731 — incubation and lesion types; 8509089 — lesion-type frequencies and chronicity; 16510000 — elephantiasis.

4. Genetic / Molecular Information

Not applicable (host). Donovanosis is an infectious disease with no causal human gene, no pathogenic germline/somatic variant, no modifier genes, no disease-defining epigenetic changes, and no chromosomal abnormalities. There is no inheritance, penetrance, expressivity, or carrier frequency.

Pathogen molecular biology (limited): K. granulomatis shows ~95% 16S rRNA identity to Klebsiella and ~94% to Enterobacter; sequencing of 16S rRNA + phoE (2089 bp) supported reclassification as Klebsiella granulomatis comb. nov. Because the organism is fastidious and hard to culture, its genome and virulence factors remain poorly characterized; a defined virulence repertoire is not established.

Evidence: 10555350; 10482295; 22239475 — "Because of the difficulty in growing this bacterium… its characteristics have not been sufficiently defined."

5. Environmental Information

• Environmental/occupational toxins: none implicated.
• Lifestyle factors: high-risk sexual behavior; multiple partners; migration between urban/rural endemic areas (identified as a driver of transmission and HIV co-risk in South African studies). Minimal condom use in affected populations.
• Infectious agent: Klebsiella (Calymmatobacterium) granulomatis — Gram-negative bacillus; NCBI Taxonomy Klebsiella granulomatis; gamma-Proteobacteria; Enterobacteriaceae. Humans are the only known host/reservoir; no environmental or animal reservoir is established.

Evidence: 1398660 — sexual-behavior/migration patterns; 10482295 — taxonomy.

6. Mechanism / Pathophysiology

Ordered causal chain (initiating infection → clinical manifestation)

1. Sexual/auto-inoculation exposure deposits K. granulomatis onto genital/inguinal epithelium (often at microabrasions) → leads to local colonization. (demonstrated: sexual transmission; exact portal inferred)
2. Bacteria are phagocytosed by tissue macrophages/histiocytes and survive/replicate within cytoplasmic vacuoles (phagosomes) → results in an intracellular reservoir (Donovan bodies). (demonstrated by ultrastructure)
3. Persisting intracellular bacteria drive chronic granulomatous inflammation — recruitment of plasma cells, neutrophils, and activated macrophages with few lymphocytes → leads to granulation-tissue formation. (demonstrated histologically)
4. Ongoing inflammation and proteolysis erode the epithelium and induce pseudoepitheliomatous hyperplasia at ulcer margins → results in the characteristic beefy-red, friable, bleeding ulcer that enlarges peripherally. (demonstrated)
5. Branch A (chronic fibrosis): persistent inflammation traps and constricts lymphatics → leads to lymphatic obstruction → genital elephantiasis / lymphedema and cicatricial/sclerotic scarring, strictures. (demonstrated mechanism, 16510000)
6. Branch B (neoplasia): decades-long chronic ulceration and epithelial hyperplasia predispose to malignant transformation → squamous cell carcinoma. (inferred from case reports)
7. Branch C (HIV facilitation): the friable, readily bleeding ulcer disrupts the mucosal barrier → facilitates HIV-1 entry/transmission (portal of entry + blood contact). (epidemiologically demonstrated)
8. Branch D (spread): direct extension/autoinoculation and (rarely) hematogenous/lymphatic dissemination → extragenital, pelvic, or disseminated lesions. (demonstrated in case reports)

Detail by category

• Cellular processes: chronic inflammation (GO:0006954), phagocytosis (GO:0006909), granuloma formation; macrophage activation (increased lysosomes, rough ER, filopodia on ultrastructure).
• Immune involvement: predominantly innate/macrophage-centered with prominent plasma-cell (humoral) infiltrate; sparse lymphocytes; the organism resists intracellular killing, enabling persistence. Immunodeficiency (HIV) worsens/prolongs disease.
• Tissue damage mechanisms: inflammatory tissue destruction, ulceration, fibrosis/sclerosis, lymphatic obstruction; not toxin- or ischemia-driven.
• Molecular pathways / metabolic / epigenetic / omics: Not characterized — no transcriptomic, proteomic, metabolomic, or defined signaling-pathway data exist for donovanosis (knowledge gap due to culture difficulty).
• Cell types (CL): macrophage (CL:0000235), plasma cell (CL:0000786), neutrophil (CL:0000775). GO cellular component: phagocytic vesicle/phagosome (GO:0045335).

Evidence: 9856642 (intramacrophage localization); 2777345 (ultrastructure of inflammatory response); 18317211 (plasma-cell/histiocyte histology, Donovan bodies); 16510000 (lymphatic constriction → elephantiasis); 2063236 (HIV facilitation).

7. Anatomical Structures Affected

• Organ/system level: reproductive/genitourinary system and integumentary system (skin) are primary. Secondary: inguinal soft tissue, lymphatics (obstruction), and rarely pelvis/bone (dissemination).
• Primary sites (~90%): external genitalia and inguinal/perineal region — penis, prepuce, coronal sulcus, glans; vulva, labia, fourchette; also uterine cervix (UBERON:0000002) and vagina (UBERON:0000996). Perianal/anal lesions with ano-receptive intercourse.
• Extragenital (rare): lip/oral cavity, and skin sites such as the foot; disseminated pelvic/visceral disease historically reported.
• Tissue/cell level: epithelial tissue (pseudoepitheliomatous hyperplasia) and dermal connective/granulation tissue; key cells = macrophages/histiocytes (CL:0000235), plasma cells (CL:0000786), neutrophils (CL:0000775).
• Subcellular: bacteria within macrophage cytoplasmic vacuoles/phagosomes (GO:0045335).
• Localization/lateralization: lesions localize to sites of sexual contact; inguinal involvement may be unilateral or bilateral; "kissing lesions" from autoinoculation on apposed skin.
• UBERON suggestions: external genitalia; UBERON:0000996 (vagina); UBERON:0000002 (cervix); UBERON:0002097 (skin of body); inguinal region.

Evidence: 8735293 (rectal/pelvic + genital); 9924476 (extragenital foot); 18317211 (cervix).

8. Temporal Development

• Onset: adult-onset, in sexually active individuals; insidious/chronic onset after an incubation period of ~50 days (reported range ~1–12 weeks, up to months). Not congenital; neonatal/perinatal transmission is rare.
• Progression: untreated disease is slowly progressive with peripheral enlargement and local tissue destruction over months–years; stages run from papule → early ulcer → extensive ulcerogranulomatous/hypertrophic disease → sclerotic/cicatricial end-stage with scarring, lymphedema/elephantiasis, and rare malignant transformation.
• Course pattern: chronic progressive; not self-limiting. Relapse can occur 6–18 months after apparently adequate therapy, warranting follow-up.
• Remission: treatment-induced (antibiotics) — healing from ulcer margins; spontaneous remission is uncommon.
• Critical intervention window: early antibiotic treatment prevents tissue destruction, scarring, elephantiasis, and reduces HIV-cofactor risk.

Evidence: 26882914 (incubation ~50 days; treat until healed); 8509089 (chronicity).

9. Inheritance and Population

• Epidemiology: rare and geographically restricted; endemic "hot spots" — Papua New Guinea, South Africa (KwaZulu-Natal/Durban epidemic 1988–97), India, Brazil, and formerly Aboriginal communities in Australia. Marked global decline; described in 2026 as "well on the way to being eradicated." Precise global incidence/prevalence figures are not maintained in standard registries (SEER/GBD do not track it separately); it is now seen mostly as sporadic imported cases in non-endemic countries.
• Infectivity: low/mildly infectious — only 1/21 regular partners were infected in one Durban series, supporting feasibility of elimination programs.
• Inheritance/penetrance/carrier frequency/founder effects/consanguinity: Not Applicable (infectious, non-genetic).
• Demographics: affects sexually active adults, roughly 15–40 years (series mean age ~22 in women). Sex ratio varies by setting; classic literature reports a male predominance (e.g., 130 men vs 41 women in one Durban series), though other series (antenatal/gynecology clinics) are female-predominant, reflecting ascertainment. Higher burden in lower-income, rural, and marginalized populations in endemic regions.
• Geographic variant distribution: Not characterized (limited pathogen genomics).

Evidence: 41016613 ("significant global decline… well on the way to being eradicated"); 26882914 (endemic countries); 7750949 (unique geography); 8509089 (sex distribution, low partner infectivity).

10. Diagnostics

• Cornerstone — cytology/histopathology: microscopic identification of Donovan bodies (intracytoplasmic, bipolar "safety-pin" bacteria within macrophages/histiocytes) on crush/tissue smears stained with Giemsa/Wright/RapiDiff or on biopsy. Histology: granulation tissue with dense plasma-cell infiltrate, neutrophil microabscesses, enlarged vacuolated histiocytes containing Donovan bodies, and pseudoepitheliomatous hyperplasia.
• Molecular: PCR (including colorimetric-detection assays) developed for genital-ulcer specimens; increases sensitivity/specificity where available. LOINC/SNOMED codes exist for genital-ulcer pathogen testing.
• Culture: difficult/not routine (fastidious; grown historically in human peripheral-blood monocyte co-culture and Hep-2 cells).
• Biomarkers/imaging/electrophysiology/omics: no specific serum biomarker; imaging only for complications (deep/pelvic/bone extension); no omics-based diagnostics.
• Genetic testing: Not Applicable (no host genetic component; WGS/WES/panels/karyotype/CMA/FISH not indicated).
• Clinical criteria & differential diagnosis: diagnosis is clinical + cytologic/PCR confirmation. Differential: primary syphilis (chancre), chancroid (H. ducreyi), lymphogranuloma venereum (C. trachomatis L1–L3), genital herpes, secondary bacterial/fungal infection; and non-infectious mimics — squamous cell carcinoma, Behçet disease, aphthosis, psoriasis, fixed drug eruption, sexual trauma. Distinguishing features of donovanosis: chronic, painless, beefy-red, friable, bleeding ulcer usually without true regional lymphadenitis. No pathogen is identified in up to 25% of genital-ulcer patients.
• Screening: no asymptomatic/newborn/carrier screening; case-finding via STI services and partner notification.

Evidence: 26882914 (Donovan bodies + PCR); 22335265 (genital-ulcer differential; up to 25% undiagnosed); 39566736 (non-infectious mimics); 18317211 (histology).

11. Outcome / Prognosis

• Prognosis with treatment: excellent — highly curable with antibiotics; ulcers re-epithelialize over weeks. Early treatment prevents disfigurement and complications.
• Mortality: very low; donovanosis is rarely directly fatal. No standardized survival statistics (non-lethal, rare disease). Disease-specific mortality is negligible except via complications (secondary infection, or SCC).
• Morbidity/disability: without treatment — extensive genital ulceration, tissue destruction/mutilation, scarring, urethral/vaginal/anal strictures, genital elephantiasis/lymphedema, and psychosexual morbidity. Long-standing lesions carry a small risk of squamous cell carcinoma.
• Recovery: high recovery potential with therapy; established fibrosis/elephantiasis and tissue loss may be irreversible and require surgery.
• Prognostic factors: duration/extent of lesions at presentation, HIV coinfection (prolonged healing, treatment failure risk), and treatment adherence. No molecular prognostic biomarkers.

Evidence: 26882914 (treat until healed); 7750949 (treatment failure in advanced HIV); 19061590 / 24554002 / 26396449 (SCC complication); 16510000 (elephantiasis).

12. Treatment

• First-line pharmacotherapy: Azithromycin (macrolide; inhibits 50S ribosome) 1 g weekly (or 500 mg daily) continued until all lesions have fully healed (minimum ~3 weeks). NCIT:C734; CHEBI:2955; ATC J01FA10.
• Alternative regimens (≥3 weeks / until healed):
• Doxycycline 100 mg twice daily (tetracycline) — genital-ulcer guidance specifies 21 days. NCIT:C744; CHEBI:50845.
• Trimethoprim–sulfamethoxazole (co-trimoxazole) 160/800 mg twice daily. NCIT:C265.
• Erythromycin 500 mg four times daily (preferred in pregnancy). NCIT:C61780.
• Ceftriaxone and ciprofloxacin reported as further alternatives.
• Adjuncts: add a parenteral aminoglycoside (e.g., gentamicin) if lesions do not respond, especially in HIV-positive patients; prolonged therapy in advanced HIV.
• Surgery/interventional: reserved for complications — excision of fibrotic/mutilating tissue, correction of strictures/elephantiasis, or resection of secondary SCC.
• Supportive care: wound care, analgesia, treatment of secondary infection; partner evaluation/treatment.
• Advanced/experimental therapeutics (gene/cell/RNA/targeted/immuno-therapy) and pharmacogenomics: Not Applicable — no gene-guided therapy; standard antibiotics suffice. No active registered clinical trials specific to donovanosis.
• Treatment outcome: high response/cure rates; monitor for relapse at 6–18 months. Adverse events are drug-class–typical (GI upset with macrolides/tetracyclines; photosensitivity with doxycycline; sulfa hypersensitivity).

Evidence: 26882914 / 21097731 (azithromycin first-line); 22335265 (doxycycline 21 days).

13. Prevention

• Primary prevention: safer-sex practices (condoms), reduction in number of partners, health education, and prompt treatment of index cases and sexual partners to interrupt transmission. No vaccine exists (immunization Not Applicable).
• Secondary prevention: early detection/treatment in STI clinics; syndromic management of genital ulcer disease in endemic settings (adapted locally); partner notification/treatment; abstinence until lesions heal.
• Tertiary prevention: complete antibiotic courses to prevent tissue destruction, strictures, elephantiasis, and malignant transformation; surveillance for relapse and SCC; management of HIV coinfection.
• Public-health interventions: community-based elimination programs are feasible given low infectivity and restricted geography — the Australian Aboriginal donovanosis elimination program is a documented success and proposed model; donovanosis eradication is framed as an opportunity to also curb HIV-1 spread.
• Genetic counseling/carrier screening: Not Applicable.

Evidence: 12473810 (successful Australian elimination program; syndromic management); 7750949 (global eradication opportunity linked to HIV control).

14. Other Species / Natural Disease

• Host range: Humans are the only known natural host; no established zoonotic reservoir or naturally occurring animal disease is documented for K. granulomatis.
• Taxonomy of pathogen: Klebsiella granulomatis (NCBI Taxonomy). Closely related human pathogens in the genus: K. pneumoniae, K. rhinoscleromatis (causes rhinoscleroma), K. oxytoca.
• Comparative biology: mechanistic parallels with rhinoscleroma (K. rhinoscleromatis) — another chronic granulomatous Klebsiella infection with intramacrophage bacteria (Mikulicz cells analogous to Donovan-body–laden histiocytes).
• Breeds/orthologous genes/zoonosis/cross-species susceptibility: Not Applicable / Not documented.

Evidence: 10555350 (relatedness to K. pneumoniae, K. rhinoscleromatis).

15. Model Organisms

• No established animal or genetic disease model exists. The organism's fastidious growth requirements (only re-cultured after >30 years in human peripheral-blood monocyte co-culture and Hep-2 cell systems) have precluded standard mouse/rat/zebrafish/invertebrate models, and there are no knockout/transgenic/humanized models (host genetics is irrelevant).
• In vitro systems used: human monocyte co-cultures and Hep-2 cells for isolation and ultrastructural study.
• Limitations / research gap: absence of tractable models and a complete genome is the principal barrier to studying virulence factors, immune evasion, and pathway-level mechanisms.

Evidence: 9856642 (monocyte co-culture / tissue ultrastructure); 22239475 (culture difficulty; "more studies needed to understand bacterial genetics").

Supported vs Refuted Hypotheses

Supported (evidence-backed): 1. Donovanosis is caused by intracellular Gram-negative Klebsiella (Calymmatobacterium) granulomatis (16S/phoE phylogeny). 2. Pathology is macrophage-based granulomatous inflammation with Donovan bodies (ultrastructure/histology). 3. Azithromycin is first-line, curative therapy (guidelines). 4. Disease is rare, geographically restricted, and declining toward eradication (reviews). 5. Donovanosis is a cofactor for HIV-1 acquisition/transmission (P=0.02 in men; risk rises with lesion duration). 6. Chronic disease causes elephantiasis (lymphatic obstruction) and rarely SCC (mechanism + case reports).

Refuted / Not Applicable: - No host causal gene, inheritance, penetrance, or carrier frequency (infectious disease). - No established animal model or knockout/transgenic system. - No omics/pathway-level molecular profiling; no vaccine; no gene/cell/RNA therapy.

Mechanistic Model (Synthesis)

 Sexual / auto-inoculation of K. granulomatis (~50-day incubation)
                 │
                 ▼
 Phagocytosis by dermal MACROPHAGES (CL:0000235)
                 │
                 ▼
 Intracellular survival in cytoplasmic vacuoles (GO:0045335)
        → DONOVAN BODIES  (pathognomonic)
                 │
                 ▼
 Chronic GRANULOMATOUS inflammation
 (plasma cells CL:0000786 + neutrophils CL:0000775)
 + pseudoepitheliomatous hyperplasia
                 │
                 ▼
 Beefy-red, FRIABLE, bleeding ULCER  (HP:0200035)
        │              │                 │
        ▼              ▼                 ▼
  Lymphatic       Long-standing      Bleeding portal
  constriction    lesion →           → HIV-1 acquisition
  → ELEPHANTIASIS  SCC (rare)         & transmission (cofactor)
  (<a href="https://pubmed.ncbi.nlm.nih.gov/16510000/" rel="noopener noreferrer" title="Visit PubMed page for PMID 16510000" class="pubmed-badge" style="display:inline-flex;align-items:center;text-decoration:none;white-space:nowrap;"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="14" height="14" class="pubmed-icon" style="display:inline !important;width:14px;height:14px;min-width:14px;min-height:14px;flex-shrink:0;vertical-align:middle;margin-right:3px;"><rect x="1" y="1" width="14" height="14" rx="2" fill="#326599"/><text x="8" y="12" text-anchor="middle" style="font-size:11px;font-weight:bold;font-family:Arial,sans-serif;fill:white;">P</text></svg>16510000</a>)  (<a href="https://pubmed.ncbi.nlm.nih.gov/19061590/" rel="noopener noreferrer" title="Visit PubMed page for PMID 19061590" class="pubmed-badge" style="display:inline-flex;align-items:center;text-decoration:none;white-space:nowrap;"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="14" height="14" class="pubmed-icon" style="display:inline !important;width:14px;height:14px;min-width:14px;min-height:14px;flex-shrink:0;vertical-align:middle;margin-right:3px;"><rect x="1" y="1" width="14" height="14" rx="2" fill="#326599"/><text x="8" y="12" text-anchor="middle" style="font-size:11px;font-weight:bold;font-family:Arial,sans-serif;fill:white;">P</text></svg>19061590</a>)    (<a href="https://pubmed.ncbi.nlm.nih.gov/2063236/" rel="noopener noreferrer" title="Visit PubMed page for PMID 2063236" class="pubmed-badge" style="display:inline-flex;align-items:center;text-decoration:none;white-space:nowrap;"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="14" height="14" class="pubmed-icon" style="display:inline !important;width:14px;height:14px;min-width:14px;min-height:14px;flex-shrink:0;vertical-align:middle;margin-right:3px;"><rect x="1" y="1" width="14" height="14" rx="2" fill="#326599"/><text x="8" y="12" text-anchor="middle" style="font-size:11px;font-weight:bold;font-family:Arial,sans-serif;fill:white;">P</text></svg>2063236</a>)

The unifying theme is that donovanosis is a macrophage-parasitizing intracellular infection whose clinical severity flows from the chronicity of the granulomatous response rather than acute toxicity. This explains the slow tempo, the friable vascular ulcers, the late fibrotic/lymphatic and neoplastic complications, the HIV-cofactor role, and why a single mechanistic intervention — sustained intracellular-active antibiotic therapy (azithromycin) — is curative and why elimination programs succeed (breaking the sole human transmission chain).

Evidence Base — Key Papers and How They Support the Findings

Consistency of evidence: Findings are internally consistent across independent guidelines (European 2010/2016), large clinical series (Durban), and mechanistic ultrastructural studies. Taxonomic reclassification is supported by two independent sequencing studies; the HIV-cofactor role by a large cross-sectional study with statistically significant associations. The main evidentiary weakness is reliance on case reports/series for complication rates (SCC, elephantiasis) and the near-total absence of pathogen omics data.

Limitations & Future Directions

• The pathogen's culture difficulty leaves its genome, virulence factors, and molecular immunology poorly defined; whole-genome sequencing and in vitro/organoid infection models are key future needs.
• Epidemiologic surveillance is sparse (no dedicated global registry); true incidence/prevalence and sex/age distributions are uncertain and setting-dependent.
• Modern PCR-based diagnostics and controlled treatment trials are limited by the disease's rarity.
• Evidence is dominated by case reports/series and expert-guideline consensus rather than RCTs.
• Several template sections (host genetics, model organisms, omics, pharmacogenomics) are inherently Not Applicable to a non-genetic infectious disease.

Proposed Follow-up Actions

1. Whole-genome sequencing of K. granulomatis from clinical isolates (via monocyte/Hep-2 co-culture) to define virulence factors, capsule/LPS loci, and confirm genome-scale Klebsiella placement.
2. Develop a tractable infection model (humanized macrophage system, skin organoid, or small-animal model) to study intracellular persistence, Donovan-body formation, and antibiotic penetration.
3. Standardized PCR surveillance in remaining endemic foci (PNG, India, Brazil) to quantify true incidence and monitor progress toward eradication.
4. Prospective cohort follow-up to estimate the risk and triggers of squamous-cell-carcinoma transformation, currently known only anecdotally.
5. Integrate donovanosis elimination with HIV-prevention programs, leveraging the demonstrated HIV-cofactor relationship (2063236).
6. Cost-effectiveness analysis of azithromycin to support universal first-line adoption (historical cost barrier; 11394976).
7. Public-health communication to counter "flesh-eating infection" misinformation and reduce stigma (41016613).

Key Citations (PMID)

41016613 · 42486240 · 10555350 · 10482295 · 22239475 · 12635932 · 26882914 · 21097731 · 12473810 · 11394976 · 8509089 · 2063236 · 7750949 · 1398660 · 8735293 · 16510000 · 18317211 · 9856642 · 2777345 · 11100808 · 19061590 · 24554002 · 26396449 · 9924476 · 22335265 · 39566736