Study of the vectorial capacity of Migonemyia migonei (França) and Pintomyia fischeri (Pinto) (Diptera: Psychodidae) in the transmission of Leishmania (Leishmania) infantum chagasi Cunha & Chagas and Leishmania (Viannia) braziliensis Vianna

Abstract

American visceral leishmaniasis (AVL) is a zoonosis widespread in Brazil and in São Paulo state (SP). It has been registered in the canine and human populations of several urban centers. Leishmania (L) infantum chagasi infection has been found in canine and feline populations in new areas of the Greater São Paulo region in the absence of the recognized vector, Lutzomyia longipatpis. Differently from other areas, where AVL transmission occurs in a consolidated urban environment in Greater São Paulo, it occurs in these new areas in a transitional urban/rural environment. In these latter there are residual forests in which the anthropophilic phlebotomines Pintomyia fischeri and Migonemyia migonei predominate and human cases of American cutaneous leishmaniasis (ACL) have been registered. We propose to investigate the vectorial capacity of these two species in the transmission of the two agents: L (L) i. chagasi and Leishmania (Viannia) braziliensis, comparing them with that of Lutzomyia longipalpis and Nyssomyia intermedia, vector, respectively, of the AVL and ACL agents. For the identification of the vectorial capacity the following parameters will be investigated: the density of the four sandfly species attracted, under natural conditions, to these parasites' hosts and frequency of the sandflies' blood-feeding on them, proportion of sandflies experimentally infected by the two parasites in dogs and/or hamsters, probability of daily sandfly survival, the extrinsic incubation period of the parasite in the vector, the duration of the gonotrophic cycle and the transmission of the parasite to hamsters (under laboratory conditions). We expect the results to demonstrate the vectorial capacity of Nig. migonei and Pi. fischeri in the transmission of L. chagasi and L. braziliensis. Further, due to the widespread distribution of these two sandfly species in forested areas of the São Paulo state, we would then alert the epidemiological surveillance authorities regarding the risk of AVL transmission in these environments. (AU)