An infection caused by the microorganism Coxiella burnetii
(rickettsia), a parasite of cattle. Cattle excrete the microorganisms in their milk or feces. Humans become
infected usually by inhaling
dust that is contaminated
by infected animal material; sometimes infection comes from drinking infected milk, since
the rickettsiae are somewhat
resistant to pasteurization.
After an incubation period
of two to four weeks, symptoms appear suddenly. These consist of fever, headaches, prostration, cough, and muscle and chest pain. X-ray studies usually show an inflammation of the lung, although the cough
may be slight. Occasionally
the heart may be affected, sometimes months after
the original infection. In severe cases, hepatitis is common. The disease may be acute, or chronic
and relapsing, but is rarely fatal.
is by avoiding contact
with infected cattle. If the disease develops, symptoms
may be suppressed by the administration of antibiotics, although this will not necessarily eradicate the infection.