LUTZOMYIA-VERRUCARUM CAN TRANSMIT LEISHMANIA-PERUVIANA, THE ETIOLOGICAGENT OF ANDEAN CUTANEOUS LEISHMANIASIS

In much of the endemic area for cutaneous leishmaniasis (uta) in the P eruvian Andes, the only 2 anthropophilic sandfly species present are L utzomyia peruensis and Lu. verrucarum. On the basis of a single confir med isolation of Leishmania peruviana (the aetiological agent of uta) from a wild Lu. peruensis, and apparent associations between sandfly a bundance and the incidence of uta, it is generally believed that Lu. p eruensis is the most important vector. In this paper, a potential role for Lu. verrucarum in the transmission of uta is indicated by laborat ory experiments which show that this species is vectorially competent for L. peruviana. Individual or pooled colonized sandflies were permit ted to take a second blood meal on 22 susceptible golden hamsters at v arying intervals after feeding on hamsters previously infected with L. peruviana. Transmission was achieved by a single infected sandfly (of a total of 59) following a 15 d incubation period. Transmission was r ecognized by the characteristic clinical response (footpad swelling) a ssociated with hamsters which have been inoculated with L. peruviana, and by the presence of parasites in aspirates made from the swollen fo otpad, detected by the polymerase chain reaction (PCR) and by parasite isolations in biphasic blood-agar culture medium. The identity of the parasite isolates was also confirmed by PCR (specific for parasites i n the L. braziliensis complex). This is the first reported experimenta l transmission of L. peruviana by any sandfly species.