Mapping the Silent Threat: A Comprehensive Analysis of Chagas Disease Occurrence in Riverside Communities in the Western Amazon.

Chagas disease (CD) is a typical tropical illness caused by Trypanosoma cruzi. The objective of this study was to assess the prevalence of Chagas disease in communities in two states of the Brazilian Amazon. Data collection occurred in July in the Alto Juruá region of Acre and in December in the communities of Humaitá, Amazonas, in 2019. A total of 477 participants were included in the study. In the communities of Alto Juruá, triatomine collections and analyses of T. cruzi infection were also carried out. All confirmed cases were found in the state of Acre, resulting in a total prevalence of 1.67. Of these eight cases, seven underwent ECG, all of which were concluded as normal by the physician team's cardiologists. Seventeen triatomine bugs, all belonging to the Rhodnius genus, were captured. The natural infection rate by T. cruzi was 25% in the Nova Cintra community and 66.67% in the Boca do Moa community (Alto Juruá). This research found that more than 1% of the studied population exhibited positive serological results for Chagas disease in the riverine communities during the study period, representing a small portion of cases among those who have not yet been diagnosed.

First report of Panstrongylus megistus (Hemiptera, Reduviidae, Triatominae) in the State of Acre and Rondônia, Amazon, Brazil.

INTRODUCTION: This article reports, for the first time, the occurrence of Panstrongylus megistus in the Brazilian Western Amazon. METHODS: Specimens of P. megistus were collected in the cities of Rio Branco, Acre and Extrema, Rondônia. RESULTS: The number of triatomine species in the State of Acre increased from eight to nine and in Rondônia from seven to eight. This was also the first report of P. megistus in the Brazilian Western Amazon. CONCLUSION: The occurrence of P. megistus in the Western Amazon evidences an epidemiological alert, since it is an important vector of T. cruzi.

Histidine-rich protein 2 (pfhrp2) and pfhrp3 gene deletions in Plasmodium falciparum isolates from select sites in Brazil and Bolivia.

More than 80% of available malaria rapid diagnostic tests (RDTs) are based on the detection of histidine-rich protein-2 (PfHRP2) for diagnosis of Plasmodium falciparum malaria. Recent studies have shown the genes that code for this protein and its paralog, histidine-rich protein-3 (PfHRP3), are absent in parasites from the Peruvian Amazon Basin. Lack of PfHRP2 protein through deletion of the pfhrp2 gene leads to false-negative RDT results for P. falciparum. We have evaluated the extent of pfhrp2 and pfhrp3 gene deletions in a convenience sample of 198 isolates from six sites in three states across the Brazilian Amazon Basin (Acre, Rondonia and Para) and 25 isolates from two sites in Bolivia collected at different times between 2010 and 2012. Pfhrp2 and pfhrp3 gene and their flanking genes on chromosomes 7 and 13, respectively, were amplified from 198 blood specimens collected in Brazil. In Brazil, the isolates collected in Acre state, located in the western part of the Brazilian Amazon, had the highest percentage of deletions for pfhrp2 25 (31.2%) of 79, while among those collected in Rondonia, the prevalence of pfhrp2 gene deletion was only 3.3% (2 out of 60 patients). In isolates from Para state, all parasites were pfhrp2-positive. In contrast, we detected high proportions of isolates from all 3 states that were pfhrp3-negative ranging from 18.3% (11 out of 60 samples) to 50.9% (30 out of 59 samples). In Bolivia, only one of 25 samples (4%) tested had deleted pfhrp2 gene, while 68% (17 out of 25 samples) were pfhrp3-negative. Among the isolates tested, P. falciparum pfhrp2 gene deletions were present mainly in those from Acre State in the Brazilian Amazon. These results indicate it is important to reconsider the use of PfHRP2-based RDTs in the western region of the Brazilian Amazon and to implement appropriate surveillance systems to monitor pfhrp2 gene deletions in this and other parts of the Amazon region.

Sustained clearance of Mansonella ozzardi infection after treatment with ivermectin in the Brazilian Amazon.

Therapy for mansonelliasis is challenging because there is no standard drug recommended for its treatment. This non-randomized study was conducted to evaluate the effectiveness of a single dose of 0.15 mg/kg of ivermectin to reduce Mansonella ozzardi microfilaraemia in infected persons. A total of 74 patients were studied within the municipality of Lábrea, which is located in Amazonas State, Brazil. The patients were treated with ivermectin after detection of the parasite by blood examination. Significant microfilaraemia reduction was observed and its residual effect was maintained for at least 12 months. There was no significant change in the laboratory blood count, hepatic metabolites, and nitrogen-bounding compound excreta dosage values that could compromise the use of this drug, demonstrating that ivermectin has a low toxicity level.

Doença de Chagas: registro de um caso agudo transfusional / Chaga's disease: an acute transfusional case report

Registro de um caso agudo de doença de Chagas tranfusional em criança de 4 anos, com diagnóstico de leucemia linfocítica aguda, em Säo Paulo, Capital. A investigaçäo epidemiológica levou à confirmaçäo da positividade sorológica do doador, procedente de área endêmica de doença de Chagas. Säo feitas consideraçöes a respeito da necessidade de se realizar triagem sorológica adequada em doadores de sangue. Ressalta-se que este se constitui no primeiro caso notificado à Superintendência de Controle de Endemia (SUCEN) da Secretaria de Estado da Saúde de Säo Paulo, nos últimos cinco anos