First described in Australia in 1935, Q fever is a rickettsial disease with acute and chronic stages. Q fever differs from other rickettsial diseases in that it is caused by inhalation of infected particles, not by a tick bite. The respiratory system is the main organ system affected, although GI and cardiac systems also are affected. Dairy and slaughterhouse workers are most at risk.
Patients initially present with influenzalike symptoms.
Often in acute Q fever, specific findings may not exist. In chronic Q fever, findings consistent with endocarditis and hepatitis more frequently are found. Humans are infected by inhalation of C burnetii . Why chronic Q fever develops in certain patients is unknown. C burnetii localizes in the mammary glands, uterus, and feces of these animals.