Síntese dos resultados dos inquéritos nacionais

Abstract

RESUMOAqui se busca correlacionar os resultados dos grandes inquéritos nacionais realizados no final da década de 1970 e início da década de 1980 (entomológico, sorológico e eletrocardiográfico) que serviram de base para orientar as ações de controle da doença de Chagas no país. Verificouse uma maior proporção de infectados nas áreas correspondentes àquela de distribuição de Triatoma infestans, a espécie reconhecidamente com maior capacidade vetorial entre as cinco identificadas como as mais importantes no Brasil à época. Achado similar foi observado para a área de dispersão de Triatoma sordida, pela coincidência existente com grande parte daquela de distribuição de T. infestans, especialmente na região central do país de onde é nativa, e não pela sua relevância na transmissão. No semiárido do nordeste do país, centro de endemismo de Triatoma brasiliensis e de Triatoma pseudomaculata, as taxas de soro-prevalência de infecção humana foram bastante menores, ainda que se possa atribuir a ambos vetores importância na manutenção da endemia chagásica na região. Para Panstrongylus megistus ocorreram variações de acordo com as suas características de maior ou menor domiciliação. Sempre que domiciliado pode-se comprovar ter papel relevante na transmissão domiciliar de Trypanosoma cruzi, como no litoral úmido do nordeste, onde em alguns casos era vetor exclusivo, como no Recôncavo Baiano. A partir dos dados do inquérito de soroprevalência foi realizado estudo eletrocardiográfico em onze estados, o qual mostrou variações regionais evidentes nas manifestações clínicas observadas. Palavras-chaves: Doença de Chagas. Inquéritos epidemiológicos. ABSTRACTThis article aims to correlate the main results of three large national surveys on Chagas disease (entomologic, seroprevalence and electrocardiographic) carried out in Brazil from late 1970's to early 1980's, which served as baseline for definition of the control measures adopted in the country. The proportion of infected people was much higher in areas where Triatoma infestans, the most efficient vector of Chagas disease among the five principal species involved in transmission at that time, was predominant. Similar result was observed in places where Triatoma sordida was dispersed, mainly in the country's central region, which corresponds to its native area. This finding is due to the coincidence observed in the geographic distribution of both vectors, since T. sordida is not considered to play an important role in transmission. In the Northeastern semi-arid, endemic area for Triatoma brasiliensis and Triatoma pseudomaculata, rates of human infection were much lower, although both vectors may have some relevance in the maintenance of the disease. As for areas with Panstrongylus megistus, human infection varied according to the levels of domiciliation. Whenever domiciled, like in the humid northeastern coastal area, its involvement in transmission can be clearly demonstrated. In some parts of Bahia State it represented the exclusive vector of the disease. Based upon the results...

2 nd Brazilian Consensus on Chagas Disease, 2015

“…Thus, mechanisms directly related to the enzootic cycle of infection, such as extradomiciliary vector transmission or visitation of wild vectors to households, in addition to oral transmission (also mediated by vectors, in most cases), have to have relevance as main modes of T. cruzi transmission to human populations (22) (27) (65) . (66) .…”

“…This was achieved by the development of systemized actions of chemical control of domiciled vector populations, introduced in 1975, with a range of coverage of the endemic area in 1983 (20) (22) (66) . These actions have taken place on a regular basis since then.…”

“…In several Brazilian regions, environmental changes favoring the adaptation of vectors to artificial environments, thus establishing new spaces for the appearance of disease, have been observed (22) (23) (39) (65) (66) . Similarly, it has also been observed the domiciliation of secondary species, even in a much smaller scale to that seen previously to the control of T. infestans (22) (23) (39) (66) .…”

Description of a newly discovered Triatoma infestans (Hemiptera: Reduviidae) Foci in Ibipeba, State of Bahia, Brazil

“…The wide distribution of T. infestans has been attributed to transport associated with human migration and enhanced species adaptation to the intradomicilliary environment, including sheltering within wall cracks, roofs, human apparel, under beds, and additional micro-habitats 6 . Additionally, studies have shown frequent human infection in areas of concentrated T. infestans 7 . Recently, a resident of Ibipeba observed the presence of a triatomine in his dwelling, raising important epidemiological questions regarding the immergence of triatomine foci and transmission of Chagas disease.…”

Biologic and Genetics Aspects of Chagas Disease at Endemic Areas

“…The main results of three large national surveys on Chagas disease (entomologic, seroprevalence and electrocardiographic) carried out in Brazil from late 1970s to the early 1980s served as baseline for the definition of the control measures adopted in the country [14]. The proportion of infected people was much higher in areas where Triatoma infestans , the most efficient vector of Chagas disease among the five principal species involved in transmission at that time, was predominant.…”