Q Fever

Q fever is an acute zoonosis caused by Coxiella burnetii. Clinical: abrupt fever, fatigue, headache, myalgia, interstitial pneumonia, no rash. Described by Derrick in Queensland, Australia (1937).

Common Symptoms

Dai Chao; fatigue; dyspnea; bilirubin...; night sweats; abdominal pain; fatigue; nausea; remittent fever; peribronchial...; hepatomegaly

Causes and Pathogenesis

C. burnetii: filterable; replicates in host-cell vacuoles; no OX cross-agglutinin; non-toxic to lab animals; highly resistant (7-9 months in dry sand at 4-6°C, years at -56°C; 60-70°C/30-60 min to kill). Worldwide; maintained by subclinical livestock infections; sheep/cattle/goats are main reservoirs. Present in feces/urine/milk/tissue (especially placenta) → infectious aerosols. Animal-tick cycle maintains it. Humans inhale aerosols or drink raw milk. Pathology: small-vessel endothelial swelling/thrombosis; interstitial pneumonitis (lower lobes) with fibrin/lymphocyte/monocyte exudate, severe lobar-like; granulomatous hepatitis; myocarditis/endocarditis/pericarditis with vegetations/aortic sinus rupture/valve perforation; also spleen/kidney/testis.

Treatment

Drug therapy, supportive therapy

Preventive Measures

(1) Isolate patients; disinfect excreta; isolate pregnant livestock; strict disinfection of birth products/placenta. (2) Slaughterhouse/abattoir workers use protective gear; rodent/tick control; boil milk 10 min. (3) Vaccinate exposed workers/livestock (killed vaccine has local reactions; live attenuated vaccine by scarification/oral sugar pill is effective).

Department to Visit

It is recommended to visit the Infectious Diseases department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.