[Evidence of transmission of visceral leishmaniasis by Lutzomyia cruzi in the municipality of Jaciara, State of Mato Grosso, Brazil]

Abstract

Introduction: The municipality of Jaciara was classified in 2003 as a transmission area for visceral leishmaniasis in outbreak situations. This study aimed to establish evidence of transmission of Leishmania (Leishmania) infantum chagasi by Lutzomyia cruzi in the municipality of Jaciara, State of Mato Grosso, Brazil.

Methods: This municipality is located 127 km from the state capital (Cuiabá) and is an important center for ecotourism practitioners. Females of Lutzomyia cruzi, captured using CDC traps, were dissected to confirm the species and stored at -20ºC in pools of 10 individuals for DNA extraction, generic PCR, specific RFLP and electrophoresis on polyacrylamide gel.

Results: The entomological survey showed abundant occurrence of Lutzomyia cruzi and absence of Lutzomyia longipalpis (the main vector for Leishmania (Leishmania) infantum chagasi). One of the three samples showed a characteristic DNA band from Leishmania (120 bp) in generic PCR. To confirm the Leishmania species via RFLP, positive controls for Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum chagasi digested with restriction enzyme HaeIII were used. A pattern of bands similar to Leishmania (Leishmania) infantum chagasi was found in one sample, thus confirming the detection of natural infection with Leishmania (Leishmania) infantum chagasi in Lutzomyia cruzi.

Conclusions: The occurrences of positive cases in humans and dogs, the presence of Lutzomyia cruzi and the absence of Lutzomyia longipalpis together with the detection of natural infection with Leishmania (Leishmania) infantum chagasi, indicate that Lutzomyia cruzi participates in visceral leishmaniasis transmission in Jaciara, State of Mato Grosso, Brazil.