Leishmania braziliensis in the squirrel monkey: development of primary and satellite lesions and lack of cross-immunity with Leishmania donovani.

Three female and 2 male adult laboratory-reared squirrel monkeys (Saimiri sciureus) that previously had been inoculated with Leishmania (Leishmania) donovani and had recovered from experimental visceral leishmaniasis were each inoculated intradermally at the dorsal base of the tail with 2.2 x 10(7) culture-derived promastigotes of Leishmania (Viannia) panamensis. The progression and regression of subsequent lesions were examined for 36 wk in all 5 monkeys after which 3 of the monkeys were killed (1 with a primary lesion and all with satellite lesions) and the 2 surviving monkeys (1 with primary lesion and both with satellite lesions) were treated with 104 mg/kg/day of meglumine antimoniate for 10 days. All of the monkeys developed a primary lesions at the site of injection of the parasite and later developed satellite lesions peripheral to the primary nodule. The primary lesions had disappeared from 3 of the 5 monkeys by 36 wk, whereas satellite lesions persisted on all at this time. Satellite lesions were present at 52 wk after treatment and persisted for 169 wk in the 2 surviving monkeys. The histopathologic appearance of the lesions was characterized as granulomatous inflammation. Our results indicated that squirrel monkeys that had recovered from visceral leishmaniasis remained susceptible to infection with L. (V). panamensis.