Experimental transmission of Leishmania chagasi, causative agent of neotropical visceral leishmaniasis, by the sandfly Lutzomyia longipalpis

Abstract

THE phlebotomine sandfly Lutzomyia longipalpis Lutz & Neiva (Diptera: Psychodidae) has long been suspected to be the vector of Leishmania chagasi Marques da Cunha & Chagas, in the principal foci of human visceral leishmaniasis (‘kala azar’) in Latin America¹. In general, the distribution of this sandfly coincides with the human disease, and the insect is a common domestic or peri-domestic species which feeds avidly on man. Lu. longipalpis has been found naturally infected with promastigote flagellates which could have been those of L. chagasi^2–3, but on none of these occasions was the parasite inoculated into susceptible laboratory animals and its true identity remains unknown. Previous attempts to experimentally transmit L. chagasi by the bite of Lu. longipalpis have failed⁴. We report here the first experimental transmissions of the parasite by laboratory-bred Lu. longipalpis, thus providing further evidence that this sandfly is a major vector of American visceral leishmaniasis.