Q fever

From Cow

Q fever, a worldwide zoonotic disease, is caused by the Gram-negative bacteria Coxiella burnetti and spread by pregnant cattle.

C. burnetii is a parasite of bovine phagocytes, closely related to Francisella tularensis. The bacteria localizes in mammary glands, supramammary lymph nodes, placenta and uterus[1].

Human contact occurs by drinking raw milk[2], contact with infected placenta or during processing of cattle in abattoirs, where aerosol is inhaled by workers.

Infections in cattle are usually subclinical but can cause anorexia, infertility, mastitis and abortion.

Diagnosis is primarily by immunoflourescence or PCR testing of postmortem samples.

Treatment of suspect cattle is best approached with prophylactic tetracyclines given parenterally.

Vaccination has prevented infection in calves and improved fertility and reduced shedding in previously infected cattle.


  1. Merck Vet Manual
  2. Valergakis GE et al (2012) Coxiella burnetii in bulk tank milk of dairy cattle in south-west England. Vet Rec 171(6):156