[Mycobacterium fortuitum pulmonary infection in a healthy 17-year-old man]

A 17-year-old man was admitted with a 5-month history of intermittent dyspnea on exertion, 10 kg weight loss, cough, sputa and fever. He did not smoke, had no apparent underlying pulmonary disease, and was not immunocompromised. Mycobacterium fortuitum was cultured from sputa at admission. Chest radiograph showed many thin-walled cavities and infiltration in the bilateral middle and upper fields. Chest CT detected multiple cystic lesions that were not revealed in conventional X-ray. It was suggested that the formation of the cystic lesions was one of the predisposing factor of Mycobacterium fortuitum pulmonary infection in this patient. The pneumonic change improved after six-month treatment using isoniazid, rifampicin and streptomycin, despite in vitro resistance of the bacilli to all of these drugs.