is found around the world. It is an infection caused by the
bacteria Coxiella burnetii which can cause pneumonia and
hepatitis (liver inflammation) in its early stage, and infection
of the heart valves (endocarditis) in its chronic stage.
The incubation period (time to development of
symptoms) for early (acute) Q fever
is approximately 20 days. In acute Q fever,
the 3 main types of syndromes include flu-like syndrome,
pneumonia, and hepatitis. Flu-like syndrome is usually self-
limited, lasts up to 3 wks, and may involve high fevers,
headaches, and muscle aches. Pneumonia can occur in up to a third
of individuals -- most cases are relatively mild and include fever
and cough, yet some severe cases have been reported. Hepatitus is
another common consequence of Q Fever,
which can occur alone or with concurrent pneumonia. Other less
common features of acute Q fever
include rashes, meningitis, myocarditis (inflammation of the heart
muscle), and pericarditis (inflammation of heart lining).
Chronic Q fever
develops in individuals who have been infected for over 6 months.
Its main feature is infection of the heart valves. Individuals at
highest risk include those with underlying heart valve
abnormalities, as well as people with weakened immune systems.
Other less common features of chronic Q fever
are infection of aneurysms, liver dysfunction (cirrhosis), and
lung scarring (interstitial pulmonary fibrosis).