A 19-year-old man, with no remarkable past medical history, consulted his physician in September 2007, 2 days after his return from a 1½ year trip to Australasia. First, he travelled in Australia for 10 months, and then in Thailand, Cambodia and finally in Laos where he spent the last 10 days of his trip. In Laos, he fell in a river and knocked his ankles against stones, resulting in several cutaneous wounds which he neglected. Two days after his return to France, he complained of fever, arthralgias, chills and conjunctivitis. His physician noticed oedema and scabby wounds on the ankles. He prescribed oxacillin, 6 g per day orally. Two days later, the patient was still febrile but reported no other symptoms, notably no oliguria. The physician changed the treatment to ceftriaxone, 1g per day intravenously. Simultaneously, abnormal blood analyses prompted hospitalisation of the patient: creatinine 360 µmol/l, leucocyte count, 13340/mm3, C reactive protein level, 148 mg/l. In contrast, proteinaemia was normal, no proteinuria was detected, and blood and urine culture remained sterile. No Plasmodium was detected on blood smears. Cerebrospinal fluid was normal. Cardiac and urinary tract ultrasound, as well as chest x-ray, were normal. Twelve days after his return, a PCR assay targeting the 16S rRNA gene detected Leptospira interrogans from a skin wound biopsy. Attempts to detect Leptospira species by PCR and culture from urine remained negative. Serology became positive 1 week after the patient’s admission. He recovered fully after a 1 week course of ceftriaxone.