Q fever endocarditis in a 6-year-old child.

A 6-year-old boy with a congenital bicuspid aortic valve presented with finger clubbing and hypertrophic osteoarthopathy, and subsequently he developed severe hypertension. The hypertension was successfully treated by nephrectomy, at which a thrombosed mycotic aneurysm of the renal artey was found. Echocardiography showed the presence of aortic valve vegetations. Blood cultures were sterile, but high antibody titres to the phase 1 and 2 antigens of Coxiella burneti strongly suggested Q fever infection. We believe this is the first reported case of Q fever endocarditis in early childhood.