EXPERIMENTAL LEPROSY IN MONKEYS .1. SOOTY MANGABEY MONKEYS - TRANSMISSION, SUSCEPTIBILITY, CLINICAL AND PATHOLOGICAL FINDINGS

A total of 31 sooty mangabey monkeys (SMM) (Cercocebus torquatus atys) inoculated by various routes with differing numbers of SMM-origin Myc obacterium leprae (ML) and 4 SMM inoculated with human-origin ML were observed for 4-12 years. SMM-origin ML was more pathogenic in SMM than human-origin ML. The spectrum of disease ranged from indeterminate to borderline and lepromatous in different animals. Some animals develop ed pure neural leprosy. Erythema nodosum leprosum (SNL) was also obser ved. Combined intravenous/intracutaneous (IV/IC) routes of inoculation more effectively induced advancing, disseminated lepromatous forms of leprosy; IV or IC routes alone were less effective at comparable dose s. Total IV/IC doses of SMM-origin ML equal to or greater than 5x10(8) , with morphologic indices (MIs) ranging from 5 to 10%, produced advan cing, disseminated LL leprosy in 92% of SMM. Lower IV/IC doses and ino culations by a single IV or IC route produced fewer leprosy infections and more spontaneous regressions. As a species, captive SMM are highl y susceptible to experimental leprosy and provide an excellent model f or the longitudinal study of leprosy.