II. Pathophysiology
- Coxiella Burnetii
- Gram Negative, small coccobacilli
- Obligate Intracellular Bacteria
- Similar to Rickettsiae, but has been reclassified to the family Coxiellaceae
- C. Burnetii uses host ATP within host cell to grow and divide
- Spore forming (Endospore)
- C. Burnetii can form an endospore (similar to Clostridium species)
- Endospore form is resistant to heat and dry air
- Endospore form allows organism to survive outside host cells for extended periods
- Organism lies dormant in endospore form (must be intracellular to grow and divide)
- Transmission
- Exposure to farm animals (esp. cattle, goats, sheep)
- Typically transmitted via aerosolized C. Burnetii spores
- Animal feces
- Dried cow placenta
- Dried tick feces on hides
- Contaminated soil
- May also be transmitted by the ingestion of unpasteurized milk
- To be destroyed, Coxiella Burnetii endospores must be heated to at least 60 C
- Tick Borne Illness transmission occurs, but is rare
- Incubation
- Three weeks (ranges from 9-40 days)
III. Symptoms
- Flu-like symptoms
- Fever
- Malaise
- Headache
- Myalgias
- Arthralgias
- Respiratory symptoms (mild, Atypical Pneumonia similar to Mycoplasma pneumonia)
- Dry cough
- Pleuritic Chest Pain
- Gastrointestinal symptoms
IV. Labs
- Blood Cultures are typically negative
- Coxiella Burnetii PCR
- Serology (IFA)
V. Management: Acute Infections
- Precautions
- See other references for chronic infections, endocarditis or comorbid endocarditis risk
- Non-Pregnant Adults and Children age >8 years
- Doxycycline 2.2 mg/kg up to 100 mg orally twice daily for 2 weeks
- Pregnancy
- Trimethoprim-Sulfamethoxazole DS 1 orally twice daily
- Continued until later third trimester to prevent Preterm Labor
- Discontinued prior to delivery to prevent Kernicterus
- Trimethoprim-Sulfamethoxazole DS 1 orally twice daily
- Children age <8 years
- Trimethoprim-Sulfamethoxazole for 14 days (see link for dosing)
VI. Complications
- Atypical Pneumonia
- Acute Respiratory Distress Syndrome (ARDS)
- Granulomatous Hepatitis
- Vascular Infections
-
Bacterial Endocarditis (2% of cases)
- Often culture negative
- Melenotte (2019) Clin Infect Dis 69(11):1987-1995 +PMID: 30785186 [PubMed]
- Chronic Infection (<5% of cases)
VII. Prognosis
- Most cases are mild and resolve spontaneously within 2 weeks
- However, Bacterial Endocarditis and chronic infections may complicate infection
VIII. Resources
- Q Fever (Wikipedia)
IX. References
- (2025) Sanford Guide, accessed on IOS 2/14/2025
- Black, Martin, DeVos (2018) Crit Dec Emerg Med 32(8): 3-12
- Nordurft-Froman and DeVos (2022) Crit Dec Emerg Med 36(4): 4-15
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| Definition (NCI_CDISC) | Any bacterial organism that can be assigned to the species Coxiella burnetii. |
| Definition (NCI) | A species of aerobic, Gram negative, coccobacilli shaped bacteria in the phylum Proteobacteria. This species is obligately intracellular, sporeforming, acidophilic, pleomorphic and catalase positive. C. burnetti is pathogenic, being the causative agent of Q fever. |
| Definition (MSH) | A species of gram-negative bacteria that grows preferentially in the vacuoles of the host cell. It is the etiological agent of Q FEVER. |
| Definition (CSP) | species of gram negative bacteria that grows preferentially in the vacuoles of the host cell; etiologic agent of Q fever; historically classified within the Rickettsiales order, is now taxonomically placed in the Legionellales order, Coxiellaceae family. |
| Concepts | Bacterium (T007) |
| MSH | D016997 |
| SnomedCT | 22533000 |
| LNC | LP16682-4, MTHU010909 |
| Swedish | Coxiella burnetii |
| Czech | Coxiella burnetii |
| Finnish | Coxiella burnetii |
| Russian | KU-LIKHORADKI VOZBUDITEL', KOKSIELLY BERNETA, COXIELLA BURNETII, КОКСИЕЛЛЫ БЕРНЕТА, КУ-ЛИХОРАДКИ ВОЗБУДИТЕЛЬ |
| English | burnetii coxiella, coxiella burnetii, Coxiella burnetii (Derrick 1939) Philip 1948, Rickettsia burneti, Rickettsia diaporica, COXIELLA BURNETII, Coxiella burnetii (organism), Coxiella burnetii |
| Polish | Coxiella burnetii |
| Norwegian | Coxiella burnetii |
| Spanish | Coxiella burnetii (organismo), Coxiella burnetii |
| French | Coxiella burnetii |
| German | Coxiella burnetii |
| Italian | Coxiella burnetii |
| Dutch | Coxiella burnetii, Rickettsia burnetii |
| Portuguese | Coxiella burnetii |
Ontology: Q Fever (C0034362)
| Definition (NCI) | A bacterial infection caused by Coxiella burnetii. It is transmitted to humans by the inhalation of infected air particles or contact with fluids and feces of infected animals. Signs and symptoms include the abrupt onset of fever, headache, myalgias, and weakness. |
| Definition (MSH) | An acute infectious disease caused by COXIELLA BURNETII. It is characterized by a sudden onset of FEVER; HEADACHE; malaise; and weakness. In humans, it is commonly contracted by inhalation of infected dusts derived from infected domestic animals (ANIMALS, DOMESTIC). |
| Definition (CSP) | acute infectious disease caused by Coxiella burnetii; characterized by a sudden onset of fever,headache, malaise, and weakness; in humans, it is commonly contracted by inhalation of infected dusts derived from infected domestic animals. |
| Concepts | Disease or Syndrome (T047) |
| MSH | D011778 |
| ICD9 | 083.0 |
| ICD10 | A78 |
| SnomedCT | 260588007, 86012006, 266205000, 154375001, 186788009 |
| LNC | LA10498-6 |
| English | Fevers, Q, Q Fevers, Fever, Q, Nine-mile fever, Q-fever (diagnosis), Coxiella burnetii infection, Q-fever, Fevers, Coxiella burnetii, Query Fever, Fevers, Query, Query Fevers, Fever, Query, Coxiella burnetii Fever, Coxiella burnetii Fevers, Fever, Coxiella burnetii, Nine Mile fever, Q Fever [Disease/Finding], fever q, fever query, query fever, q fever, q-fever, Infection due to Coxiella burnetii (disorder), Balkan grippe, Q fever, Infection due to Coxiella burnetii, Abattoir fever, Balkan influenza, Query fever, Q fever (disorder), Q; fever, Balkan; influenza, fever; Q, fever; nine Mile, infection; Coxiella burnetii, influenza; Balkan, nine Mile; fever, Coxiella burnetii; infection, Q fever (disorder) [Ambiguous], Q Fever |
| Dutch | Coxiella burnetii-infectie, Nine Mile-koorts, Balkan; griep, Coxiella burnetii; infectie, Nine Mile; fever, Q; koorts, fever; Nine Mile, griep; Balkan, infectie; Coxiella burnetii, koorts; Q, Koorts, Q-, Q-koorts |
| German | Coxiella burnetii-Infektion, Schlachthausfieber, Q-Fieber |
| Italian | Infezione da Coxiella burnetii, Febbre delle nove miglia, Febbre Q |
| Spanish | Infección por Coxiella burnetti, Fiebre de las nueve millas, Fiebre por Coxiella burnetti, Fiebre de Query, infección por Coxiella Burnetii (trastorno), infección por Coxiella Burnetii, Fiebre Query, fiebre Q (concepto no activo), fiebre Q (trastorno), fiebre Q, fiebre de los mataderos, gripe de los Balcanes, infección por Coxiella burnetii, influenza de lso Balcanes, Fiebre Q |
| Japanese | Ｑ熱リケッチア感染, Ｑ熱, Qﾈﾂﾘｹｯﾁｱｶﾝｾﾝ, Qﾈﾂ, 9ﾏｲﾙﾈﾂ, ９マイル熱, Q熱, ナインマイル熱, 濠州Q熱, 米国Q熱 |
| Swedish | Q-feber |
| Czech | Q-horečka, Infekce způsobená Coxiella burnetti, Devítimílová horečka, Q horečka, horečka Q |
| French | Fièvre de Nine Mile, Fièvre Q, Coxiellose, Fièvre des abattoirs, Fièvre du Queensland, Grippe des Balkans, Infection à Coxiella burnetii, Maladie de Derrick-Burnet |
| Portuguese | Febre das nove milhas, Febre por Coxiella burnetii, Febre de Query, Infecção por Coxiella burnetti, Rickettsiose por Coxiella burnetti, Endocardite por Coxiella burnetii, Febre Query, Febre Q |
| Finnish | Q-kuume |
| Russian | KU-LIKHORADKA, КУ-ЛИХОРАДКА |
| Korean | 큐열 |
| Croatian | Q GROZNICA |
| Polish | Choroba Derricka i Burneta, Gorączka queenslandzka, Gorączka Q |
| Hungarian | Q-láz, Q láz, Coxiella burnetii fertőzés, Nine-mile láz |
| Norwegian | Query-feber, Q-feber, Coxiella burnetii-feber |
