Occurrence of Triatoma costalimai (Hemiptera: Reduviidae) in different environments and climatic seasons: a field study in the Brazilian savanna

Abstract

Introduction: Trypanosoma cruzi-infected specimens of Triatoma costalimai have been detected in domiciliary units of Central Brazil, thereby maintaining the potential risk of vectorial transmission of Chagas disease. The aim of this study was to determine the occurrence and natural infection of T. costalimai in different environments (gallery forest, dry forest and peridomicile) and climatic seasons (wet and dry), in the municipality of Mambaí, State of Goiás, Brazil. Methods: Triatomines were captured in October 2010 and in June 2011, employing two different methods (manual capture and mouse-baited adhesive traps). The insects were later separated by sex and nymphal stage, counted and examined parasitologically by abdominal compression and microscopic analysis of feces. Results: Triatoma costalimai was found in three environments and in the two seasons studied. Overall, capture success of 900 traps and 60 blocks of rocks inspected was 5.8% and 11.7%, respectively. The occurrence of T. costalimai was higher among rocks in the peridomicile, where 97% of the 131 specimens were captured. The proportion of nymphs (98%) was much higher than that of adults, which were only detected in peridomicile. Most (95%) insects were captured during the wet season, with predominance of early-stage nymphs. None of the 43 specimens examined were infected by trypanosomatids. Conclusions: The results indicate a greater occurrence of T. costalimai in peridomiciliary environments and during the wet season in Mambaí, Goiás, highlighting the synanthropic behavior of this triatomine species in one area of the Brazilian savanna and the importance of entomological surveillance.

Factors associated with the occurrence of Triatoma sordida (Hemiptera: Reduviidae) in rural localities of Central-West Brazil

“…It is important to note that the DU where the nymphs were collected was located near rock outcroppings, common habitats for this species ( Mello 1981 ). T. costalimai has also been found in the peridomiciliary areas of other municipalities in GO ( Oliveira & Silva 2007 , Machiner et al 2012 ).…”

An overview on the ecology of Triatominae (Hemiptera:Reduviidae)

“…temperature values, rainfall, altitude, vegetation). Although underexplored for Triatominae, the method has given good prediction results, especially on the well sampled species, generating largely coincident predicted and known areas of distribution (Gurgel-Gonçalves et al, 2012;Ibarra-Cerdeña et al, 2009).…”

“…Collected among calcareous rocks close to nests of mocó (Cavidae) (Lent and Wygodzinsky, 1979;Machiner et al, 2012) Adults found inside human houses and peridomestic structures (Machiner et al, 2012) Yes (Mello and Borges, 1981) T. deaneorum # # Adults found inside human houses (Carcavallo et al, 2001) # #…”

Triatoma costalimai Naturally Infected by Trypanosoma cruzi: A Public Health Concern

“…The occurrence of this natural infection of T. costalimai by T. cruzi was initially evidenced by Mello and Borges 15 and Mello, 16 in Mambaí -Goiás State (GO), but with infection prevalences of 13.5% and 0.4%, respectively. More recently, also in Mambaí-GO, Machiner et al 17 reported a higher occurrence of T. costalimai in rock outcrops located in the peridomicile, near hens and pigs, comparable to a wild environment, indicating the synanthropic potential of the species, without the presence of T. cruzi infection. In the present study, a similar environment was observed with the high infection prevalence, suggesting the transmission cycle of the parasite among the wild animals that inhabit the rock outcrops where the triatomines were captured.…”