Fièvre récurrente chez un Marocain

: Tick-borne relapsing fever is a zoonosis caused by spirochetes of the genus Borrelia, transmitted by hematophagous ticks. This life-threatening condition is still misdiagnosed. We report a case of tick-borne relapsing fever in a 54 year-old man in Morocco with a history of hiking, who was hospitalized for an isolated fever. On admission, the clinical examination showed no specific signs. The laboratory assessment showed inflammatory syndrome with disturbance of the liver function. The blood culture was sterile. Serology was negative for HIV and Lyme disease, as were all the rest of the paraclinical tests. The patient's course was marked by spontaneous resolution of the fever and then, seven days later, the onset of a new episode of fever. Malaria was suspected and a blood sample was sent to the parasitology department. The thick smear and blood smear stained with May-Grunwald Giemsa showed the presence of spirochetes. Tick-borne relapsing fever was diagnosed and the patient responded favorably to treatment by cycline drugs. This disease is poorly known and should be considered in cases of presence of intermittent fever without a specific clinical-laboratory picture, according to epidemiological context. The diagnosis is confirmed by the presence of spirochetes on thick smear and blood or cerebrospinal fluid smear stained with MGG.