RESUMEN
An outbreak of cutaneous leishmaniasis reached epidemic proportions among military personnel in Guyana during the period from November, 1977 to March, 1980. As the patients presented from widely separated areas of the hinterland it is likely that cutaneous leishmaniasis is endemic throughout the virgin tropical rain forest of Guyana, although infection is normally sporadic. A striking clinical feature was the 'spirotrichoid' involvement of the draining lymphatics and nodes in half the cases, which histologically all came from the middle region of the spectrum (groups II, III or IV of Ridley's 1980 classification). All the cases tested were serologically positive to a Leishmania braziliensis antigen. One hundred and ten patients were successfully treated with pentamidine, with minimal side-effects, but some required a second course. Four relapsed patients all belonged to the same histological group.