Lutzomyia verrucarum can transmit Leishmania peruviana, the aetiological agent of Andean cutaneous leishmaniasis

Abstract

In much of the endemic area for cutaneous leishmaniasis (uta) in the Peruvian Andes, the only 2 anthropophilic sandfly species present are Lutzomyia peruensis and Lu. verrucarum. On the basis of a single confirmed isolation of Leishmania peruviana (the aetiological agent of uta) from a wild Lu. peruensis, and apparent associations between sandfly abundance and the incidence of uta, it is generally believed that Lu. peruensis is the most important vector. In this paper, a potential role for Lu. verrucarum in the transmission of uta is indicated by laboratory experiments which show that this species is vectorially competent for L. peruviana. Individual or pooled colonized sandflies were permitted to take a second blood meal on 22 susceptible golden hamsters at varying 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 recognized by the characteristic clinical response (footpad swelling) associated with hamsters which have been inoculated with L. peruviana, and by the presence of parasites in aspirates made from the swollen footpad, 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 in the L. braziliensis complex). This is the first reported experimental transmission of L. peruviana by any sandfly species.