Trypanosoma cruzi infection in Triatoma sordida before and after community-wide residual insecticide spraying in the Argentinean Chaco.

MACCHIAVERNA NP; GASPE MS; ENRIQUEZ GF; TOMASSONE L; GÜRTLER RE; CARDINAL MV

ACTA TROPICA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 143 p. 97 - 102

0001-706X

Triatoma sordida is a secondary vector of Trypanosoma cruzi in the Gran Chaco and Cerrado eco-regionswhere it frequently infests peridomestic and domestic habitats. In a well-defined area of the humidArgentine Chaco, very few T. sordida were found infected when examined by optical microscopic exam-ination (OM). In order to further assess the role of T. sordida and the relative magnitude of subpatentbug infections, we examined the insects for T. cruzi infection, parasite Discrete Typing Units (DTUs) andbloodmeal sources using various molecular techniques. Among 205 bugs with a negative or no OM-based diagnosis, the prevalence of infection determined by kDNA-PCR was nearly the same in bugscaptured before (6.3%) and 4 months after insecticide spraying (6.4%). On average, these estimates weresixfold higher than the prevalence of infection based on OM (1.1%). Only TcI was identified, a DTU typ-ically associated with opossums and rodents. Chickens and turkeys were the only bloodmeal sourcesidentified in the infected specimens and the main local hosts at the bugs? capture sites. As birds arerefractory to T. cruzi infection, further studies are needed to identify the infectious bloodmeal hosts. Thepersistent finding of infected T. sordida after community-wide insecticide spraying highlights the need ofsustained vector surveillance to effectively prevent T. cruzi transmission in the domestic and peridomestic habitats.