Q Fever

Overview

Q fever is a zoonosis, classically acquired from cattle (also sheep and goats) — an occupational risk for abattoir workers, livestock workers, vets and National Park rangers. Transmission is by inhaling infected aerosols/dust from infected animals or animal products.

Presentation

Can present as cholestatic hepatitis or, occasionally, as atypical pneumonia. Can also cause endocarditis and bone/joint infections — both notoriously difficult to diagnose. Acute infection usually resolves spontaneously within 2–6 weeks.

Signs and symptoms: hepatitis + jaundice, high fevers with rigors, night sweats, headache, fatigue, myalgia, RUQ pain, anorexia, nausea, photophobia, cough, occasionally diarrhoea.

Chronic infection may occur in patients with:

• Prosthetic heart valve or other valvular abnormality (e.g. bicuspid aortic valve)
• Endovascular lesion (e.g. aneurysm)
• Immunosuppression

Diagnosis

Testing depends on timing from symptom onset:

• Week 1: Q fever PCR
• Weeks 1–4: Q fever serology + PCR
• Week 4+: Q fever serology alone

Treatment

Doxycycline 100 mg BD for 2 weeks.

Vaccination

Consider in at-risk patients. A formal screening process (the Q-fever “Q-tool”) is required before vaccination, and eligible patients are covered under the NSW immunisation schedule. Refer to an occupational physician for screening and vaccination.