Mycobacterium lepraein Striated Muscle of Patients with the Leprosy

Biopsies of striated muscle from leprosy patients showed the presence of Myco. Zeprae in 16 out of 20 biopsies from lepromatous cases, 3 out of 4 borderline, and 5 out of 9 tuberculoid cases; in most cases the bacilli lay chiefly within muscle fibres. BacillEfry counts performed on homogenates of 22 skin and muscle b iopsies (13 lepromatous, 3 borderline and 6 tuberculoid) showed that the concentration of bacilli in lepromatous cases was from 100 to 1000 times greater in skin than in muscle, but that in this group of treated patients a higher proportion of muscle bacilli were solid staining. In tuberculoid leprosy the total number of bacilli may be greater in muscle than in skin. Muscle involvement in human leprosy may precede the appearance of skin lesions and could also play a significant part in the development of relapse and drug resistance.