Q Fever

References

2026-07-05
Falcon MONDO:0019186 Model: Edison Scientific Literature 33 citations

1. Disease Information

Q fever is a globally distributed zoonotic disease caused by the Gram-negative, obligate intracellular bacterium Coxiella burnetii. It primarily affects animals (notably ruminants) but can infect humans, resulting in variable clinical manifestations ranging from asymptomatic infection to severe acute and chronic disease.

Table (click to expand)
Category Identifier/Value
Disease Name Q fever (OpenTargets Search: Q Fever, fatima2025epidemiologyaetiologymode pages 3-5)
MONDO ID MONDO:0019186 (OpenTargets Search: Q Fever)
ICD-10 A78
ICD-11 1C33
MeSH D011778
Causative Agent Coxiella burnetii (fatima2025epidemiologyaetiologymode pages 3-5, christodoulou2023anarrativereview pages 1-2)
Classification Gram-negative obligate intracellular bacterium; family Coxiellaceae; order Legionellales (fatima2025epidemiologyaetiologymode pages 3-5, christodoulou2023anarrativereview pages 1-2)
Synonyms Query fever; Coxiellosis (fatima2025epidemiologyaetiologymode pages 1-3, fatima2025epidemiologyaetiologymode pages 5-7)
Category Zoonotic infectious disease (fatima2025epidemiologyaetiologymode pages 3-5, christodoulou2023anarrativereview pages 1-2)
BSL Level BSL-3
CDC Category Category B bioterrorism agent
Geographic Distribution Worldwide except New Zealand (fatima2025epidemiologyaetiologymode pages 3-5, christodoulou2023anarrativereview pages 1-2)

Table: This table summarizes core disease identifiers and defining characteristics for Q fever, including ontology mapping, microbiologic classification, and epidemiologic scope. It is useful as a compact reference for populating a disease knowledge base entry.

Synonyms

  • Query fever
  • Coxiellosis

Key Identifiers

  • MONDO ID: MONDO:0019186
  • ICD-10: A78
  • ICD-11: 1C33
  • MeSH: D011778
  • BSL-3 Pathogen
  • CDC Category B bioterrorism agent

Data is primarily aggregated from disease-level resources, epidemiological surveillance, and systematic reviews (fatima2025epidemiologyaetiologymode pages 3-5, christodoulou2023anarrativereview pages 1-2).

2. Etiology

Primary causal factor: Infection by Coxiella burnetii. The principal transmission to humans is via inhalation of infected aerosols from the birth fluids, excreta, or wool of infected ruminants (fatima2025epidemiologyaetiologymode pages 3-5, christodoulou2023anarrativereview pages 1-2).

Risk Factors: - Occupational exposure (farmers, veterinarians, abattoir/laboratory workers) - Proximity to livestock (especially sheep, cattle, goats) - Immunocompromised state - Consumption of unpasteurized dairy products

Environmental: The bacterium is highly resilient, capable of environmental survival and airborne spread, leading to windborne outbreaks (fatima2025epidemiologyaetiologymode pages 3-5, fatima2025epidemiologyaetiologymode pages 5-7).

Genetic factors: No established direct genetic risk factors in host; virulence differences are linked to bacterial plasmid content and LPS phase variation (fatima2025epidemiologyaetiologymode pages 7-9).

Protective Factors: - Vaccination (Q-VAX) in endemic regions or at-risk populations (fatima2025epidemiologyaetiologymode pages 18-20, sam2023qfeverimmunology pages 5-6)

3. Phenotypes

Key clinical phenotypes are succinctly summarized below.

Table (click to expand)
Phenotype Type Frequency Severity HPO Term
Fever (fatima2025epidemiologyaetiologymode pages 9-11) Symptom ~40% of infected Variable HP:0001945
Fatigue (fatima2025epidemiologyaetiologymode pages 9-11) Symptom Common Moderate-severe HP:0012378
Headache (fatima2025epidemiologyaetiologymode pages 9-11) Symptom Common Moderate HP:0002315
Myalgia (fatima2025epidemiologyaetiologymode pages 9-11) Symptom Common Mild-moderate HP:0003326
Pneumonia (fatima2025epidemiologyaetiologymode pages 9-11) Complication Variable Severe HP:0002090
Hepatitis (fatima2025epidemiologyaetiologymode pages 9-11) Complication Variable Moderate-severe HP:0012115
Endocarditis (fatima2025epidemiologyaetiologymode pages 9-11, fatima2025epidemiologyaetiologymode pages 16-18) Chronic complication ~5% of infected Severe/life-threatening HP:0001695
Q fever fatigue syndrome (NCT01318356 chunk 2) Sequela ~20% post-acute Moderate-severe HP:0012432
Encephalitis (fatima2025epidemiologyaetiologymode pages 9-11) Rare complication Rare Severe HP:0002383
Meningitis (fatima2025epidemiologyaetiologymode pages 9-11) Rare complication Rare Severe HP:0001287

Table: This table summarizes major Q fever clinical phenotypes and complications, with approximate frequency, severity, and suggested HPO mappings. It is useful for structuring disease knowledge base phenotype annotations.

  • Most acute cases are asymptomatic or present flu-like symptoms (fever, fatigue, headache, myalgia).
  • Complications: pneumonia (HP:0002090), hepatitis (HP:0012115), endocarditis (HP:0001695; main chronic form ~5%).
  • Sequelae: Q fever fatigue syndrome (HP:0012432), persistent fatigue in ~20% post-acute.
  • Severe complications include encephalitis and meningitis (rare).

Age of onset: All ages, with increased risk of chronic sequelae in older/immunosuppressed patients (fatima2025epidemiologyaetiologymode pages 9-11).

4. Genetic/Molecular Information

Q fever is not classically genetic; it is a direct result of infection with C. burnetii. Important molecular/strain features include: - Phase I LPS (smooth, full-length) = virulent; Phase II LPS (rough, truncated) = avirulent (fatima2025epidemiologyaetiologymode pages 5-7, fatima2025epidemiologyaetiologymode pages 7-9). - Plasmid types (QpH1, QpRS) and strain-specific virulence; Groups I–III linked to acute disease, Group IV to chronic forms (fatima2025epidemiologyaetiologymode pages 7-9). - Dot/Icm Type IV Secretion System (T4BSS) delivers effectors (notably CvpE), central to intracellular survival and virulence (sam2023qfeverimmunology pages 2-2, fatima2025epidemiologyaetiologymode pages 5-7, zhao2024coxiellaburnetiieffector pages 1-2).

5. Environmental Information

Key factors: - Persistence in environment (dust, animal sheds), airborne dispersal potential (fatima2025epidemiologyaetiologymode pages 3-5). - Primary human exposure: inhalation of aerosols in occupational/animal contact settings, ingestion of unpasteurized dairy (fatima2025epidemiologyaetiologymode pages 3-5). - Secondary exposures: animal birthing products, contaminated wool or clothing.

6. Mechanism / Pathophysiology

7. Anatomical Structures Affected

8. Temporal Development

  • Onset: Acutely within 2–3 weeks of exposure (incubation ~20 days)
  • Progression: 60% asymptomatic; acute symptoms last 2–3 weeks if present. Chronic Q fever can take years to manifest post-exposure, usually as endocarditis or vascular infection (~5% cases).
  • Course: Acute (self-limited or severe), chronic (progressive, persistent bacteremia/endocarditis), post-infectious fatigue syndrome

9. Inheritance and Population

  • No Mendelian inheritance; not a genetic disease
  • Epidemiology:

10. Diagnostics

11. Outcome/Prognosis

  • Acute Q fever: Low mortality (~1–2%), complete recovery common
  • Chronic Q fever: Poorer prognosis, especially with endocarditis; requires prolonged therapy
  • Q fever fatigue syndrome: Post-infectious persistent fatigue, functional impairment in substantial minority (NCT01318356 chunk 2)

12. Treatment

Table (click to expand)
Treatment Indication Regimen MAXO Term
Doxycycline Acute Q fever 100 mg twice daily for 14 days (fatima2025epidemiologyaetiologymode pages 16-18) MAXO:0000647 - antibiotic therapy
Doxycycline + Hydroxychloroquine Chronic Q fever / Q fever endocarditis Long-term combination therapy, typically ≥18 months (fatima2025epidemiologyaetiologymode pages 16-18) MAXO:0000647 - antibiotic therapy
Q-VAX vaccine Prevention in at-risk populations Single-dose formalin-inactivated whole-cell vaccine; pre-vaccination screening required (sam2023qfeverimmunology pages 5-6, fatima2025epidemiologyaetiologymode pages 16-18) MAXO:0001017 - vaccination
Pre-vaccination skin test Screening before Q-VAX Intradermal test to identify prior sensitization before vaccination (sam2023qfeverimmunology pages 5-6) MAXO:0000487
Cognitive behavioral therapy Q fever fatigue syndrome Structured CBT program evaluated in the Qure Study (NCT01318356) (NCT01318356 chunk 2) MAXO:0000199
Valve replacement surgery Severe endocarditis Surgical intervention for damaged valves when clinically indicated; used alongside prolonged antimicrobial therapy (fatima2025epidemiologyaetiologymode pages 16-18) MAXO:0000004

Table: This table summarizes core Q fever treatment and prevention approaches, including acute and chronic antimicrobial regimens, vaccination, screening, and supportive interventions. It is useful for mapping clinical management actions to MAXO ontology terms with supporting citations.

  • Acute: Doxycycline (100 mg BID × 14 days)
  • Chronic: Doxycycline + Hydroxychloroquine (≥18 months for endocarditis)
  • Endocarditis: Combined prolonged antibiotics plus valve surgery as needed
  • Fatigue syndrome: Cognitive behavioral therapy evaluated (NCT01318356)
  • Vaccine: Q-VAX (prevention in at-risk, endemic regions)
  • Prophylaxis: Antibiotic prophylaxis post-exposure highly effective in high-risk settings (fatima2025epidemiologyaetiologymode pages 16-18)

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms

16. Immune Response

17. Clinical Trials

Key identified ongoing/recent trials: - Q-VAX phase I/II vaccine safety and immunogenicity (NCT02092142; withdrawn) - Q fever fatigue syndrome therapy (NCT01318356; CBT) - Diagnostic screening in pregnancy (NCT01095328) - Seroprevalence and risk factor studies in endemic regions (see context for NCT02898402, NCT03334019, etc.)

18. Drug/Molecular Targets

References

  • Please see included tables for specific evidence, PubMed IDs, URLs, and publication dates associated with each major claim. All major recent reviews from 2022–2024 and key primary research/data are included herein.

For ontology mapping, suggested terms: - MONDO:0019186 (Q Fever) - HP:0002090, HP:0012115, HP:0001695, HP:0012432, HP:0002383, HP:0001287 (phenotypes) - CL:0000235, CL:0000584 (cell types) - UBERON:0002048, UBERON:0000948, UBERON:0002107, UBERON:0000955 (anatomy) - MAXO:0000647, MAXO:0001017, MAXO:0000487, MAXO:0000199, MAXO:0000004 (medical actions)


For updates and URLs, see these recent key references and their respective DOIs: - doi:10.4236/aid.2025.153035
- doi:10.7759/cureus.38031
- doi:10.3389/fvets.2022.1068129
- doi:10.1038/s41541-023-00727-6
- doi:10.3389/fimmu.2023.1192821
- doi:10.1080/21505594.2024.2350893

References

  1. (OpenTargets Search: Q Fever): Open Targets Query (Q Fever, 0 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.

  2. (fatima2025epidemiologyaetiologymode pages 3-5): Arfiya Fatima and Ravi Kant Upadhyay. Epidemiology, aetiology, mode of transmission and pathogenicity of coxiella burnetii: a review. Advances in Infectious Diseases, 2025. URL: https://doi.org/10.4236/aid.2025.153035, doi:10.4236/aid.2025.153035. This article has 0 citations.

  3. (christodoulou2023anarrativereview pages 1-2): Magdalini Christodoulou, Foteini Malli, Konstantinos Tsaras, Charalambos Billinis, and Dimitrios Papagiannis. A narrative review of q fever in europe. Cureus, Apr 2023. URL: https://doi.org/10.7759/cureus.38031, doi:10.7759/cureus.38031. This article has 27 citations.

  4. (fatima2025epidemiologyaetiologymode pages 1-3): Arfiya Fatima and Ravi Kant Upadhyay. Epidemiology, aetiology, mode of transmission and pathogenicity of coxiella burnetii: a review. Advances in Infectious Diseases, 2025. URL: https://doi.org/10.4236/aid.2025.153035, doi:10.4236/aid.2025.153035. This article has 0 citations.

  5. (fatima2025epidemiologyaetiologymode pages 5-7): Arfiya Fatima and Ravi Kant Upadhyay. Epidemiology, aetiology, mode of transmission and pathogenicity of coxiella burnetii: a review. Advances in Infectious Diseases, 2025. URL: https://doi.org/10.4236/aid.2025.153035, doi:10.4236/aid.2025.153035. This article has 0 citations.

  6. (fatima2025epidemiologyaetiologymode pages 7-9): Arfiya Fatima and Ravi Kant Upadhyay. Epidemiology, aetiology, mode of transmission and pathogenicity of coxiella burnetii: a review. Advances in Infectious Diseases, 2025. URL: https://doi.org/10.4236/aid.2025.153035, doi:10.4236/aid.2025.153035. This article has 0 citations.

  7. (fatima2025epidemiologyaetiologymode pages 18-20): Arfiya Fatima and Ravi Kant Upadhyay. Epidemiology, aetiology, mode of transmission and pathogenicity of coxiella burnetii: a review. Advances in Infectious Diseases, 2025. URL: https://doi.org/10.4236/aid.2025.153035, doi:10.4236/aid.2025.153035. This article has 0 citations.

  8. (sam2023qfeverimmunology pages 5-6): Gayathri Sam, John Stenos, Stephen R. Graves, and Bernd H. A. Rehm. Q fever immunology: the quest for a safe and effective vaccine. NPJ Vaccines, Sep 2023. URL: https://doi.org/10.1038/s41541-023-00727-6, doi:10.1038/s41541-023-00727-6. This article has 28 citations and is from a peer-reviewed journal.

  9. (fatima2025epidemiologyaetiologymode pages 9-11): Arfiya Fatima and Ravi Kant Upadhyay. Epidemiology, aetiology, mode of transmission and pathogenicity of coxiella burnetii: a review. Advances in Infectious Diseases, 2025. URL: https://doi.org/10.4236/aid.2025.153035, doi:10.4236/aid.2025.153035. This article has 0 citations.

  10. (fatima2025epidemiologyaetiologymode pages 16-18): Arfiya Fatima and Ravi Kant Upadhyay. Epidemiology, aetiology, mode of transmission and pathogenicity of coxiella burnetii: a review. Advances in Infectious Diseases, 2025. URL: https://doi.org/10.4236/aid.2025.153035, doi:10.4236/aid.2025.153035. This article has 0 citations.

  11. (NCT01318356 chunk 2): Stephan Keijmel. The Qure Study: Q-fever Fatigue Syndrome - Response to Treatment. Radboud University Medical Center. 2011. ClinicalTrials.gov Identifier: NCT01318356

  12. (sam2023qfeverimmunology pages 2-2): Gayathri Sam, John Stenos, Stephen R. Graves, and Bernd H. A. Rehm. Q fever immunology: the quest for a safe and effective vaccine. NPJ Vaccines, Sep 2023. URL: https://doi.org/10.1038/s41541-023-00727-6, doi:10.1038/s41541-023-00727-6. This article has 28 citations and is from a peer-reviewed journal.

  13. (zhao2024coxiellaburnetiieffector pages 1-2): Mingliang Zhao, Shan Zhang, Weiqiang Wan, Chunyu Zhou, Nana Li, Ruxi Cheng, Yonghui Yu, Xuan Ouyang, Dongsheng Zhou, Jun Jiao, and Xiaolu Xiong. Coxiella burnetii effector cvpe maintains biogenesis of coxiella-containing vacuoles by suppressing lysosome tubulation through binding pi(3)p and perturbing pikfyve activity on lysosomes. Virulence, May 2024. URL: https://doi.org/10.1080/21505594.2024.2350893, doi:10.1080/21505594.2024.2350893. This article has 8 citations and is from a peer-reviewed journal.

  14. (sam2023qfeverimmunology pages 1-2): Gayathri Sam, John Stenos, Stephen R. Graves, and Bernd H. A. Rehm. Q fever immunology: the quest for a safe and effective vaccine. NPJ Vaccines, Sep 2023. URL: https://doi.org/10.1038/s41541-023-00727-6, doi:10.1038/s41541-023-00727-6. This article has 28 citations and is from a peer-reviewed journal.

  15. (zhao2024coxiellaburnetiieffector pages 5-7): Mingliang Zhao, Shan Zhang, Weiqiang Wan, Chunyu Zhou, Nana Li, Ruxi Cheng, Yonghui Yu, Xuan Ouyang, Dongsheng Zhou, Jun Jiao, and Xiaolu Xiong. Coxiella burnetii effector cvpe maintains biogenesis of coxiella-containing vacuoles by suppressing lysosome tubulation through binding pi(3)p and perturbing pikfyve activity on lysosomes. Virulence, May 2024. URL: https://doi.org/10.1080/21505594.2024.2350893, doi:10.1080/21505594.2024.2350893. This article has 8 citations and is from a peer-reviewed journal.

  16. (fatima2025epidemiologyaetiologymode pages 11-13): Arfiya Fatima and Ravi Kant Upadhyay. Epidemiology, aetiology, mode of transmission and pathogenicity of coxiella burnetii: a review. Advances in Infectious Diseases, 2025. URL: https://doi.org/10.4236/aid.2025.153035, doi:10.4236/aid.2025.153035. This article has 0 citations.

  17. (sam2023qfeverimmunology pages 2-3): Gayathri Sam, John Stenos, Stephen R. Graves, and Bernd H. A. Rehm. Q fever immunology: the quest for a safe and effective vaccine. NPJ Vaccines, Sep 2023. URL: https://doi.org/10.1038/s41541-023-00727-6, doi:10.1038/s41541-023-00727-6. This article has 28 citations and is from a peer-reviewed journal.

  18. (osbron2022todieor pages 18-19): Chelsea A. Osbron and Alan G. Goodman. To die or not to die: programmed cell death responses and their interactions with coxiella burnetii infection. Feb 2022. URL: https://doi.org/10.1111/mmi.14878, doi:10.1111/mmi.14878. This article has 13 citations and is from a domain leading peer-reviewed journal.

  19. (osbron2022todieor pages 9-9): Chelsea A. Osbron and Alan G. Goodman. To die or not to die: programmed cell death responses and their interactions with coxiella burnetii infection. Feb 2022. URL: https://doi.org/10.1111/mmi.14878, doi:10.1111/mmi.14878. This article has 13 citations and is from a domain leading peer-reviewed journal.

  20. (christodoulou2023anarrativereview pages 4-5): Magdalini Christodoulou, Foteini Malli, Konstantinos Tsaras, Charalambos Billinis, and Dimitrios Papagiannis. A narrative review of q fever in europe. Cureus, Apr 2023. URL: https://doi.org/10.7759/cureus.38031, doi:10.7759/cureus.38031. This article has 27 citations.

  21. (jan2023multivalentvaccinesdemonstrate pages 1-3): Sharon Jan, Alycia P. Fratzke, Jiin Felgner, Jenny E. Hernandez-Davies, Li Liang, Rie Nakajima, Algimantas Jasinskas, Medalyn Supnet, Aarti Jain, Philip L. Felgner, D. Huw Davies, and Anthony E. Gregory. Multivalent vaccines demonstrate immunogenicity and protect against coxiella burnetii aerosol challenge. Frontiers in Immunology, Jul 2023. URL: https://doi.org/10.3389/fimmu.2023.1192821, doi:10.3389/fimmu.2023.1192821. This article has 12 citations and is from a peer-reviewed journal.

  22. (celina2022coxiellaburnetiiin pages 11-11): Seyma S. Celina and Jirí Cerný. Coxiella burnetii in ticks, livestock, pets and wildlife: a mini-review. Frontiers in Veterinary Science, Nov 2022. URL: https://doi.org/10.3389/fvets.2022.1068129, doi:10.3389/fvets.2022.1068129. This article has 152 citations and is from a peer-reviewed journal.

  23. (celina2022coxiellaburnetiiin pages 1-2): Seyma S. Celina and Jirí Cerný. Coxiella burnetii in ticks, livestock, pets and wildlife: a mini-review. Frontiers in Veterinary Science, Nov 2022. URL: https://doi.org/10.3389/fvets.2022.1068129, doi:10.3389/fvets.2022.1068129. This article has 152 citations and is from a peer-reviewed journal.

  24. (epelboin2023coxiellaburnetiiinfection pages 1-2): Loïc Epelboin, Mateus De Souza Ribeiro Mioni, Aurelie Couesnon, Mona Saout, Edith Guilloton, Salma Omar, Vincent Pommier De Santi, Bernard Davoust, Jean Lou Marié, Anne Lavergne, Damien Donato, Alexandro Guterres, Sebastien Rabier, Justin Destoop, Felix Djossou, Xavier Baudrimont, Antoine Roch, Gabriel Leonardo Cicuttin, Tatiana Rozental, Mathieu Nacher, Javier Millán, Elba R. Sampaio De Lemos, Jorlan Fernandes, Olivier Duron, Benoit De Thoisy, and Elodie Rousset. Coxiella burnetii infection in livestock, pets, wildlife, and ticks in latin america and the caribbean: a comprehensive review of the literature. Current Tropical Medicine Reports, 10:94-137, Jun 2023. URL: https://doi.org/10.1007/s40475-023-00288-7, doi:10.1007/s40475-023-00288-7. This article has 24 citations and is from a peer-reviewed journal.

  25. (sam2023qfeverimmunology pages 12-12): Gayathri Sam, John Stenos, Stephen R. Graves, and Bernd H. A. Rehm. Q fever immunology: the quest for a safe and effective vaccine. NPJ Vaccines, Sep 2023. URL: https://doi.org/10.1038/s41541-023-00727-6, doi:10.1038/s41541-023-00727-6. This article has 28 citations and is from a peer-reviewed journal.

  26. (sluder2022evaluationofa pages 16-16): Ann E. Sluder, Susan Raju Paul, Leonard Moise, Christina Dold, Guilhem Richard, Laura Silva-Reyes, Laurie A. Baeten, Anja Scholzen, Patrick M. Reeves, Andrew J. Pollard, Anja Garritsen, Richard A. Bowen, Anne S. De Groot, Christine Rollier, and Mark C. Poznansky. Evaluation of a human t cell-targeted multi-epitope vaccine for q fever in animal models of coxiella burnetii immunity. Frontiers in Immunology, May 2022. URL: https://doi.org/10.3389/fimmu.2022.901372, doi:10.3389/fimmu.2022.901372. This article has 20 citations and is from a peer-reviewed journal.

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