Seroprevalence of Trypanosoma cruzi infection among unskilled urban workers in central Brazil.

A cross-sectional survey of the prevalence of Trypanosoma cruzi infection was carried out among urban unskilled workers in an endemic area in central Brazil as part of a study to assess the health impact of Chagas disease and to identify risk factors for the evolution of cardiopathy. Blood samples from 5425 male and female workers, aged 15-61 years, from 5 public institutions, were screened by indirect immunofluorescence, enzyme-linked immunosorbent assay and indirect haemagglutination for antibodies to T. cruzi. Seroprevalence varied from 8.8% to 15.6% in the different institutions and increase with age up to 55 years. More stable jobs were associated with lower seroprevalence. Migrants from São Paulo and Minas Gerais presented higher prevalence and a relative risk associated with seropositivity in relation to workers from Goiás of 2.2 (95% confidence limits, 1.4-3.5) and 1.9 (1.6-2.3), respectively.