Current status of research regarding Blastocystis sp, an enigmatic protist, in Brazil

The present study aimed to evaluate the occurrence of Blastocystis sp. in Brazilian studies over a period of years (2000-2020), as well as point out relevant aspects of this enigmatic organism. We performed a literature search using six sources of international databases. The data were divided into diagnostic by parasitological and molecular techniques, and relevant aspects. After applying the inclusion and exclusion criteria, 52 studies were included in the final analysis. The occurrence of Blastocystis sp. in Brazil ranged from 0.5% to 86.6%, as determined using parasitological techniques. The highest occurrence was in the North (27.3%) and the lowest, in the Midwest region (13.4%). In Brazil, most studies have employed molecular techniques and are concentrated in the Southeast region. The Blastocystis sp. subtype ST3 had the highest average positivity, followed by ST1 and ST2. These findings represent a panorama that reflects the reality of Brazil; thus, we believe that the effectiveness of parasitological diagnosis should be considered with regard to making an appropriate choice of technique for detecting Blastocystis sp. Additionally, we emphasize the importance of further studies in the context of molecular epidemiology with regard to this genus. Blastocystis sp. is not well understood yet, and very little information regarding this genus is available; hence, further research regarding this genus is urgently needed.

Occurrence of positivity for Trypanosoma cruzi in triatomine from municipalities in Southeastern Brazil, from 2002 to 2004 / Ocorrência e positividade para Trypanosoma cruzi em triatomíneos de municípios da região sudeste do Brasil, de 2002 a 2004

INTRODUCTION: from an epidemiological point of view, more than 120 species of triatomine (Hemiptera, Reduviidae) are known. The occurrence and positivity for Trypanosoma cruzi in triatomines in 16 municipalities of the Triângulo Mineiro and Alto Paranaíba were evaluated from January 2002 to December 2004. METHODS: the triatomines were captured basically according to the classic norms of the National Health Foundation. The parasitological exams of the triatomines were conducted according to the technique described by the Ministry of Health. During the study period, 990 specimens of triatomines were captured and of these, 771 could be examined. RESULTS: five species were identified: Triatoma sordida, Panstrongylus diasi, Panstrongylus megistus, Panstrongylus geniculatus and Rhodnius neglectus. Triatoma sordida represented 71.5 percent of all the triatomines captured, followed by Panstrongylus megistus (18 percent), Rhodnius neglectus (9.3 percent), Panstrongylus diasi (0.8 percent) and Panstrongylus geniculatus (0.4 percent). Of the total number of triatomines examined, 2.7 percent were positive for Trypanosoma cruzi. Panstrongylus megistus was the species that presented the highest rates of infection by Trypanosoma cruzi (8.3 percent), followed by Rhodnius neglectus (2.9 percent) and Triatoma sordida (1.4 percent). CONCLUSIONS: there is a need to adapt to new circumstances in epidemiology, with greater emphasis on entomological surveillance, since the potential for adaptation of secondary species of triatomines exists, especially where Chagas' disease is already under control.

INTRODUÇÃO: do ponto de vista epidemiológico mais de 120 espécies de triatomíneos (Hemiptera, Reduviidae) são conhecidas. A ocorrência e a positividade de Trypanosoma cruzi em triatomíneos de 16 municípios do Triângulo Mineiro e Alto Paranaíba foram avaliadas de janeiro de 2002 a dezembro de 2004. MÉTODOS: os triatomíneos foram capturados seguindo basicamente as normas clássicas da Fundação Nacional de Saúde. Os exames parasitológicos dos triatomíneos foram conduzidos de acordo com a técnica descrita pelo Ministério da Saúde. Durante o período de estudo, foram capturados 990 exemplares de triatomíneos, sendo que 771 dos capturados estavam em condições de serem examinados. RESULTADOS: cinco espécies foram identificadas: Triatoma sordida, Panstrongylus diasi, Panstrongylus megistus, Panstrongylus geniculatus e Rhodnius neglectus. Triatoma sordida representou 71,5 por cento de todos os triatomíneos capturados, seguido por Panstrongylus megistus (18 por cento), Rhodnius neglectus (9,3 por cento), Panstrongylus diasi (0,8 por cento) e Panstrongylus geniculatus (0,4 por cento). Dos triatomíneos examinados, 2,7 por cento foram positivos para Trypanosoma cruzi. Panstrongylus megistus foi a espécie que apresentou a maior taxa de infecção por Trypanosoma cruzi (8,3 por cento), seguida pelo Rhodnius neglectus (2,9 por cento) e Triatoma sordida (1,4 por cento). CONCLUSÕES: há necessidade de se adequar às novas circunstâncias epidemiológicas com ênfase na vigilância entomológica, uma vez que o potencial de adaptação de espécies secundárias de triatomíneos, em áreas onde a doença de Chagas está controlada, é uma preocupação.