Mycobacterium malmoense infections in immunocompetent patients.

While Mycobacterium malmoense infections were originally restricted to northern Europe, there has been an increasing number of reports of cases of infection in other countries. Two cases of infections due to Mycobacterium malmoense in immunocompetent patients in Germany are presented. In both cases a presumptive diagnosis of tuberculosis was established initially. Mycobacterium malmoense was cultured after a long incubation period (6-8 weeks). The patients were successfully treated with a triple regimen consisting of rifampicin, ethambutol and clarithromycin. The epidemiology and difficulties in diagnosis of Mycobacterium malmoense infection are discussed.