Controle do Triatoma sordida no peridomicílio rural do município de Porteirinha, Minas Gerais, Brasil

Epidemiology of Chagas disease in Jaguaruana, Ceará, Brazil. I. Presence of triatomines and index of Trypanosoma cruzi infection in four localities of a rural area

“…The peridomicile can work as a barrier space to intradomiciliary infestation if it offers favorable conditions to the triatomine survival, but it can also serve as an entrance door for colonizing dwellings that present unfavorable conditions (Forattini et al 1984, Diotaiuti et al 1998, Dias 2000. This supposition could explain the in- Exam: examined; Pos: positive; Inf.…”

Toxicological profile of deltamethrin in Triatoma brasiliensis (Hemiptera: Reduviidae) in State of Ceará, Northeastern Brazil

“…Spraying these environments requires extensive work; unstacking all of the material accumulated inside is often impossible for field agents. Consequently, triatomines (eggs, nymphs and adults) might remain in the area after insecticide application, having no or limited contact with the chemical, thereby encouraging the selection of those that are least susceptible and enabling their survival (28) (29) . Moreover, the high temperatures and ultraviolet (UV) radiation of northeastern Brazil can degrade pyrethroids faster, thereby reducing their duration, availability on treated surfaces, and their consequent triatomicide action.…”

Variability of susceptibility to deltamethrin in peridomestic Triatoma sordida from Triângulo Mineiro, State of Minas Gerais, Brazil

“…Despite insecticide spraying diffi culties and low permanence in the peridomicile, the lack of resistance and only one annual cycle of T. sordida, which means slow reconstruction of the original population, suggest that one annual spraying is suffi cient for the control of this triatomine (18) . Thus, the persistent T. sordida infestation in Triângulo Mineiro may be because of the following: 1) environmental degradation that facilitate the dispersion of T. sordida, allowing colonization in artifi cial ecotopes (5) (19) (20) ; 2) operational failures (9) ; and 3) complexity of the peridomicile in the Triângulo Mineiro region (18) .…”

“…Thus, the persistent T. sordida infestation in Triângulo Mineiro may be because of the following: 1) environmental degradation that facilitate the dispersion of T. sordida, allowing colonization in artifi cial ecotopes (5) (19) (20) ; 2) operational failures (9) ; and 3) complexity of the peridomicile in the Triângulo Mineiro region (18) . Regarding environmental degradation, studies have shown that profound modifi cations to the natural environment of the Triângulo Mineiro region to promote agriculture and increase livestock caused displacement or disappearance of the refuges and natural food sources of T. sordida, which then sought these in the alternative artifi cial environment in order to survive.…”

“…The large variety of ecotopes in these peridomiciles makes insecticide spraying an exhaustive job, which requires shifting of materials accumulated in these ecotypes, presenting an operationally impossible situation for the responsible fi eld agent. Consequently, T. sordida (eggs, nymphs, and adults) persist even after application of the insecticide, deep in piles of fi rewood, on the roofs of barns, and in a variety of other nearly inaccessible hiding places, free from contact with the active ingredient and/or in contact with sub-lethal doses, favoring their multiplication in these ecotopes (18) .…”