Trypanosoma cruzi I genotype among isolates from patients with chronic Chagas disease followed at the Evandro Chagas National Institute of Infectious Diseases (FIOCRUZ, Brazil)

ABSTRACT INTRODUCTION: Trypanosoma cruzi is the etiologic agent of Chagas disease in humans, mainly in Latin America. Trypanosome stocks were isolated by hemoculture from patients followed at Evandro Chagas National Institute of Infectious Diseases (FIOCRUZ) and studied using different approaches. METHODS: For species and genotype identification, the stocks were analyzed by parasitological techniques, polymerase chain reaction assays targeted to specific DNA sequences, isoenzyme patterns, besides sequencing of a polymorphic locus of TcSC5D gene (one stock). RESULTS: The isolates presented typical T. cruzi morphology and usually grew well in routine culture media. Metacyclic trypomastigotes were found in cultures or experimentally infected Triatoma infestans. All isolates were pure T. cruzi cultures, presenting typical 330-bp products from kinetoplast DNA minicircles, and 250 or 200-bp amplicons from the mini-exon non-transcribed spacer. Their genetic type assignment was resolved by their isoenzyme profiles. The finding of TcI in one asymptomatic patient from Paraíba was confirmed by the sequencing assay. TcVI was found in two asymptomatic individuals from Bahia and Rio Grande do Sul. TcII was identified in six patients from Pernambuco, Bahia and Minas Gerais, who presented different clinical forms: cardiac (2), digestive with megaesophagus (1), and indeterminate (3). CONCLUSIONS: The main T. cruzi genotypes found in Brazilian chronic patients were identified in this work, including TcI, which is less frequent and usually causes asymptomatic disease, unlike that in other American countries. This study emphasizes the importance of T. cruzi genotyping for possible correlations between the parasite and patient’ responses to therapeutic treatment or disease clinical manifestations.

Parasites in stool samples in the environment of Ilha da Marambaia, Rio de Janeiro, Brazil: an approach in public health / Parasitos em amostras fecais de ambiente da Ilha da Marambaia, Rio de Janeiro, Brasil: uma abordagem em saúde pública

This research aimed to describe the frequency of parasites in stool samples in the environment of Ilha da Marambaia, Rio de Janeiro, Brazil. One hundred and five stool samples were collected and processed by the coproparasitological techniques ethyl acetate sedimentation and centrifuge-flotation using saturated sugar solution. Parasites were detected in 81.9% of the samples, hookworm being the most prevalent, followed by Trichuris vulpis. Ascaris sp. eggs were also found. A high level of evolutive forms of parasites with public health risk was found in stool samples of the environment studied. We propose that health education programs, allied to an improvement of human and animal health care, must be employed to reduce the environmental contamination.

O objetivo deste estudo foi descrever a frequência de parasitos em amostras fecais coletadas no ambiente da Ilha da Marambaia, Rio de Janeiro, Brasil. Cento e cinco amostras foram coletadas e processadas pelas técnicas coproparasitológicas de sedimentação em acetato de etila e centrifugo-flutuação em solução saturada de sacarose. Foi observada positividade em 81.9% das amostras, sendo ancilostomídeo o parasito mais frequente, seguido de Trichuris vulpis. Ovos de Ascaris sp. também foram detectados. Observou-se elevada frequência de parasitos com importância em saúde pública nas fezes recolhidas no ambiente. Programas de educação em saúde, aliados a atenção dos serviços das saúdes humana e animal, devem ser empregados para redução dos níveis de contaminação ambiental.