Visceral Leishmaniasis and Natural Infection Rates of Leishmania in Lutzomyia longipalpis in Latin America

Leishmaniasis, a neglected disease caused by protozoans of the Leishmania genus, is still present in 98 countries with about two million new cases yearly worldwide. It is transmitted by female phlebotomine sandflies and presents itself as cutaneous, mucocutaneous and visceral clinical forms, depending on the Leishmania species and the parasite‐host relationship. Visceral leishmaniasis (VL) is caused by Leishmania (Leishmania) infantum chagasi, endemic in 12 countries of Latin America, with 90% of the cases reported in Brazil. VL is characterized by irregular bouts of fever, weight loss, hepatosplenomegaly and pancytopenia, being highly fatal with no treatment. The main strategy in limiting the expansion of VL, besides the treatment of human cases, is the control of the vector Lutzomyia longipalpis and its reservoirs. There are only few studies on the natural infection of Leishmania species, especially in relation to its endemic distribution. Epidemiological studies of leishmaniasis may indicate the infection rate of parasites in sandflies in order to assess the populations at risk and to direct public health control strategies. In this context, we aimed to review the main features of VL with regard the distribution of disease cases and natural infection rates of Leishmania in Lu. longipalpis in Latin America.