Host-Feeding Sources and Infection With Trypanosoma cruzi of Triatoma infestans and Triatoma eratyrusiformis (Hemiptera: Reduviidae) From the Calchaqui Valleys in Northwestern Argentina

CECERE MARIA CARLA; LEPORACE MARINA; FERNANDEZ M.PILAR; ZARATE JOAQUÍN; MORENO CLAUDIO; GURTLER RICARDO E; CARDINAL MARTA V

JOURNAL OF MEDICAL ENTOMOLOGY

ENTOMOLOGICAL SOC AMER

Año: 2016

0022-2585

We assessed the prevalence of infection with Trypanosoma cruzi, parasite genotypes (discrete typing units,DTUs), and the host-feeding sources of domestic and peridomestic Triatoma infestans Klug and Triatoma eratyrusiformisDel Ponte in eight rural communities of the subandean Calchaqui valleys in northwesternArgentina. We sought to analyze their epidemiological role in the context of routine vector surveillance and controlactions. Infection with T. cruzi was determined by optic microscopy or polymerase chain reaction (PCR)amplification of the hypervariable region of kinetoplast DNA minicircles. Parasite genotypes were identifiedthrough a multi PCR-based strategy. Bloodmeal contents were tested with a direct ELISA assay against nineantisera. Human sleeping quarters (domiciles) and peridomestic dry-shrub fences concentrated most of theT. infestans and T. eratyrusiformis infected with T. cruzi, respectively. The most frequent host-feeding sourcesof T. infestans were chickens (73.1%) in peridomiciles and humans (73.3%) in domiciles, whereas T. eratyrusiformisfed more often on cavid rodents (92.6%), which thrived in the dry-shrub fences. The main T. cruzi DTUidentified in both vectors was T. cruzi I (TcI). Triatoma eratyrusiformis was implicated in the local circulation ofTcI among cavies and perhaps mice, but infection with other typically domestic DTUs (TcVI and TcII/TcV/TcVI)indicated overlap between (peri)domestic transmission cycles in both vector species. Because dry-shrub fenceswere not targeted for routine insecticide spraying, they may act as sources of (peri)domestic reinfestation.Triatoma eratyrusiformis is an emergent secondary vector of T. cruzi and plays a significant role in the localtransmission of T. cruzi.