A multicenter comparative study of the performance of four rapid immunochromatographic tests for the detection of anti-Trypanosoma cruzi antibodies in Brazil.

Diagnosis of Trypanosoma cruzi (T. cruzi) infection in the chronic phase of Chagas disease (CD) is performed by serologic testing. Conventional tests are currently used with very good results but require time, laboratory infrastructure, and expertise. Rapid diagnostic tests (RDTs) are an alternative as the results are immediate and do not require specialized knowledge, making them suitable for epidemiologic studies and promising as a screening tool. Nevertheless, few studies conducted comparative evaluations of RDTs to validate the results and assess their performance. In this study, we analyzed four trades of rapid tests (OnSite Chagas Ab Combo Rapid Test-United States, SD Bioline Chagas AB-United States, WL Check Chagas-Argentina, and TR Chagas Bio-Manguinhos-Brazil) using a panel of 190 samples, including sera from 111 infected individuals, most of whom had low T. cruzi antibody levels. An additional 59 samples from uninfected individuals and 20 sera from individuals with other diseases, mainly visceral leishmaniasis, were included. All tests were performed by three independent laboratories in a blinded manner. Results showed differences in sensitivity from 92.8 to 100%, specificity from 78.5 to 92.4%, and accuracy from 90.5 to 95.3% among the four assays. The results presented here show that all four RDTs have high overall diagnostic ability. However, WL Check Chagas and TR Chagas Bio-Manguinhos were considered most suitable for use in screening studies due to their high sensitivity combined with good performance. Although these two RDTs have high sensitivity, a positive result should be confirmed with other tests to confirm or rule out reactivity/positivity, especially considering possible cross-reactivity with individuals with leishmaniasis or toxoplasmosis.

Congenital transmission of Trypanosoma cruzi in central Brazil. A study of 1,211 individuals born to infected mothers.

Transmission of Trypanosoma cruzi during pregnancy is estimated to occur in less than 20% of infected mothers; however, the etiopathogenesis is not completely understood. The Centre for Studies on Chagas Disease provides confirmation of T. cruzi infection for individuals living in central Brazil. In this retrospective hospital-based study, all requests for diagnosis of T. cruzi infection in individuals less than 21 years old from 1994-2014 were searched. We end with 1,211 individuals and their respective infected mothers. Congenital transmission of infection was confirmed in 24 individuals (2%) in central Brazil, an area where the main T. cruzi lineage circulating in humans is TcII. This low prevalence of congenital Chagas disease is discussed in relation to recent findings in the south region of Brazil, where TcV is the main lineage and congenital transmission has a higher prevalence (approximately 5%), similar to frequencies reported in Argentina, Paraguay and Bolivia. This is the first report to show geographical differences in the rates of congenital transmission of T. cruzi and the relationship between the prevalence of congenital transmission and the type of Tc prevalent in each region.

Congenital transmission of Trypanosoma cruzi in central Brazil. A study of 1,211 individuals born to infected mothers

Transmission of Trypanosoma cruzi during pregnancy is estimated to occur in less than 20% of infected mothers; however, the etiopathogenesis is not completely understood. The Centre for Studies on Chagas Disease provides confirmation of T. cruzi infection for individuals living in central Brazil. In this retrospective hospital-based study, all requests for diagnosis of T. cruzi infection in individuals less than 21 years old from 1994-2014 were searched. We end with 1,211 individuals and their respective infected mothers. Congenital transmission of infection was confirmed in 24 individuals (2%) in central Brazil, an area where the main T. cruzi lineage circulating in humans is TcII. This low prevalence of congenital Chagas disease is discussed in relation to recent findings in the south region of Brazil, where TcV is the main lineage and congenital transmission has a higher prevalence (approximately 5%), similar to frequencies reported in Argentina, Paraguay and Bolivia. This is the first report to show geographical differences in the rates of congenital transmission of T. cruzi and the relationship between the prevalence of congenital transmission and the type of Tc prevalent in each region.

Malária em Gestantes

Vídeo Aula que apresenta atualização sobre pincipios de eventuais complicações em gestantes com malária.

Chagas disease: increased parasitemia during pregnancy detected by hemoculture.

One hundred fifty-two Trypanosoma cruzi seropositive women were submitted to a single hemoculture; 101 were pregnant, and 51 were not pregnant. Seven tubes from each individual were harvested with liver infusion tryptose (LIT) medium and observed monthly until the fifth month. Hemocultures were positive in 50% (76 of 152) of the women. Results showed that the positivity was 29.4% (15 of 51) among non-pregnant women and 60.4% (61 of 101) in pregnant women (P < 0.05). In relation to gestational age, there were significant differences in positivity, with a higher proportion of women with positive hemocultures (20 of 25) before 21 weeks and lower after 30 weeks (10 of 21; P = 0.02). We conclude that pregnancy enhances the parasitemia in Chagas disease, with a higher effect early in pregnancy.