Fever and Chimpanzees: An Unexpected Life-Threatening Diagnosis

Tropic fever can have several causes. It is important to investigate thoroughly and consider less obvious explanations. This paper presents the case of a biologist in close contact with chimpanzees, who developed fever in the tropics. Despite treatment for some tropical diagnosis, the fever persisted. On arrival in Belgium, further diagnostics revealed an unexpected diagnosis: Citrobacter koseri endocarditis of the native aortic valve. He was treated with ceftriaxone and amikacin and underwent aortic valve replacement. C koseri is a commensal in humans and animals. It is likely that the patient was infected with this bacterium through his close contact with chimpanzees. Only a few cases of C koseri endocarditis have been published worldwide, with most patients being immunocompromised. Patients with tropical fever may have unsuspected underlying causes, like endocarditis.