Behavior of Leishmania braziliensis s.l. in golden hamsters: evolution of the infection under different experimental conditions.

Reproducibility of Leishmania braziliensis s.l. metastatic behavior in hamsters was studied for 9 isolates of L.b. panamensis and 2 of L.b. guyanensis with a previous record of metastasis. Also, the influence of corticosteroids and trauma was evaluated. In the corticosteroid-treated group, metastases appeared earlier than in the nontreated group, and localization at the site of trauma was more frequent (4/9) than in the nontreated hamsters (1/5). Nine of the 11 strains (82%) were capable of reproducing metastatic behavior. Studies on dissemination of L. b. panamensis showed that the regional lymph node is invaded as soon as 5 days postinfection, with further nonhematic dissemination to other tissues and organs in less than 4 wk.