Seroprevalence of antibodies against Trypanosoma cruzi in 13 departments of Uruguay

: In 1985 a study was undertaken of the prevalence of Trypanosoma cruzi antibodies in 13 departments of Uruguay where transmission of the parasite by the vector Triatoma infestans persists. A total of 5,924 serum samples were selected using a probabilistic method--3,840 from individuals over the age of 12 (sample I) and 2,084 from subjects who were 12 years old (sample II). The population was classified according to place of residence (capital city, non-capital city, suburban area, and rural area). The percentage of positive sera detected by indirect immunofluorescence in the different departments ranged from 1 to 11%, and overall seroprevalence for the area was 3.4%. Based on the results obtained, it was possible to distinguish three areas: A, with seroprevalence from 6 to 11%; B, 2 to 3.2%, and C, 1 to 1.4%. In sample II from the Departments of Paysandu, Soriano, Flores, Florida, and Durazno, no cases of Chagas' disease were detected, which suggests that there is no active transmission of T. cruzi in this age group in the area studied. The number of persons estimated to have the disease was 36,952, or 1.3% of the total population of Uruguay and 4% of the population in the area surveyed. These seroprevalence figures are similar to those recorded in the province of Entre Rios, Argentina, and in the neighboring municipalities of Rio Grande do Sul, Brazil.