Surveillance of seroepidemiology and morbidity of Chagas disease in the Negro River, Brazilian Amazon

Abstract

BACKGROUNDChagas disease in the Brazilian Amazon Region was previously regarded as an enzootic disease of wild animals. More recently, in situations where humans have penetrated the wild ecotope or where triatomines and/or wild animals (marsupials) have invaded human homes resulting in disease transmission, Chagas disease has come to be regarded as an anthropozoonosis. We found that the highest incidence of infection due to Trypanosoma cruzi and Chagas disease occurred among piassaba fibre gatherers and their families.OBJECTIVESConsidering the results of previous surveys, we conducted a new survey of piassaba gatherers and their families in the creeks of the Aracá, Curuduri, Demini, Ererê and Padauiri rivers, which are tributaries on the left bank of the Negro River, in the municipality of Barcelos; Barcelos-Caurés highway; Negro River in Santa Isabel of the Negro River; and Marié River, on the right bank of the Negro River.METHODSA questionnaire was applied to 482 piassaba gatherers and their families who accompanied them. We collected 5-mL blood samples (with permission from each subject), separated the serum, and performed serological tests using indirect immunofluorescence and conventional and recombinant enzyme-linked immunosorbent assays (ELISA). We performed brief clinical examination and electrocardiograms. Only 273 subjects attended our field base for detailed clinical examination and electrocardiogram.FINDINGS AND MAIN CONCLUSIONSThe questionnaire revealed that 100% of the 482 patients recognised the triatomine Rhodnius brethesi, which they had seen in the piassaba plantation and 81% in their field huts. A total of 79% of subjects had previously been bitten by this vector and 21% did not know. The 25 subjects seropositive for T. cruzi infection (5.2%) stated that they had been bitten more than 10 times by this insect. Of the 273 subjects who underwent electrocardiogram, 22% showed conditions that were possibly attributable to Chagas disease or other cardiovascular disease.

Eratyrus mucronatus Stål, 1859 and Panstrongylus rufotuberculatus (Champion, 1899) (Hemiptera, Reduviidae, Triatominae): first records in a riverside community of Rio Negro, Amazonas state, Brazil

“…Oral transmission in humans linked to the consumption of açaí juice contaminated with T. cruzi in the Rio Negro microregion (Amazonas state, Brazil) emphasizes the importance of strengthening the epidemiological surveillance service (Souza-Lima et al 2013). An outbreak with 17 cases in Santa Isabel do Rio Negro municipality confirmed and seroepidemiological and clinical studies of T. cruzi infection using samples from the population, confirm the endemicity of Chagas disease in the region (Brum-Soares et al 2010;Souza-Lima et al 2013;Coura et al 2018).…”

“…Currently, 153 living and three fossil species are known to belong to the subfamily Triatominae (Reduviidae) (Alevi et al 2020;Galvão 2020;Zhao et al 2021). In the Brazilian Amazon, some species of triatomines have been found to be naturally infected by Trypanosoma cruzi (Chagas, 1909), including Eratyrus mucronatus Stål, 1859, Microtriatoma trinidadensis (Lent, 1951), Tria toma sordida (Stål, 1859), Panstrongylus lignarius (Walker, 1837), Panstrongylus rufotuberculatus (Champion, 1899), Rhodnius brethesi Matta, 1919, Rhodnius neglectus Lent, 1954, Rhodnius paraensis Sherlock, Guitton & Miles, 1977, Rhodnius robustus Larrousse, 1927, and Rhodnius montenegrensis Rosa et al 2012(Bilheiros et al 2018Coura et al 2018;Ramos et al 2018;Madeira et al 2020).…”

Home invasion of triatomines increases the risk of Chagas disease transmission in the Brazilian Amazon

“…In our findings, the species most often found in the homes of the residents was the R. pictipes species. Moreover, in the Amazon, there are at least 10 species of T. cruzi-infected triatomines already described [25].…”

“…Recently, Coura et al [25] evaluated in the Rio Negro 482 patients (piaçaba fiber collectors and their relatives) who reported knowing the R. brethesi species in Piaçabais. Additionally, 79% reported that they were stung bitten one to ten times by these insects.…”

Implantable cardioverter-defibrillator prevents sudden death in patients with Chagas cardiomyopathy in the Brazilian Amazon

“…Since then, surveillance programs and serological surveys have been carried out, and new cases have been detected. Previous studies suggest lower morbidity levels related to CD in the Amazon region, probably due to the presence of different T. cruzi strains from those found in traditionally endemic areas 3,4 .…”