Foi estudada a parasitemia de 202 chagásicos crônicos por um período médio de 13 anos, através de repetidos xenodiagnósticos convencionais. Os pacientes tinham média de idade de 41,4 anos, residiam em área endêmica, sendo 124 do sexo feminino e 78 do sexo masculino. Foi observado que o nível de parasitemia aumentou em 14 indivíduos, diminuiu em 42 e permaneceu inalterado em 146. Porém, no geral, a parasitemia declinou. Os percentuais de chagásicos xenopositivos que foram 37,6%, 48,5%, 51% no primeiro, segundo e terceiro xenodiagnósticos, respectivamente, em 1976/78, passaram a ser 30,2% em 1988/91 (p = 0,00003). Os percentuais de pools positivos que foram 15,2%, 20,9%, 20,8% no primeiro, segundo e terceiro xenodiagnósticos, respectivamente, em 1976/78, passaram a ser 10,4% em 1988/91, (p = 0.00000001). Houve 62 pacientes que tiveram todos os xenodiagnósticos negativos e 23 que apresentaram todos os exames positivos. Os percentuais de chagásicos com alta, média e baixa parasitemias que, em 1976/78, foram, respectivamente, 9,4%; 20,8% e 69,8% passaram a ser, em 1988/91, respectivamente, 4,4%, 12,9% e 82,7%.The parasitemia of 202 chronic chagasics was studied for approximately 13 years by repetead conventional xenodiagnoses. Mean patient age was 41.1 years. They lived in an endemic area; 124 were females and 78 were males. It was seen that the level of parasitemia oscillated. It went up in 14 individuals, went down in 42 and stayed at the same level in 146. In general the parasitemia was reduced. The percentage of xenopositive chagasics, which was 37.6%, 48.5%, and 51% in the first, second and third xenodiagnosis, respectively, in 1976/78, changed to 30.2% in 1988/91 (p = 0.00003). The percentage of positive pools, whicht was 15.2%, 20.9%, 20.8% in the first, second and third xenodiagnosis, respectively, in 1976/78, changed to 10.4% in 1988/91, (p = 0.00000001). There were 62 patients whose xenodiagnoses were all negative and 23 whose exams were all positive. The percentage of chagasics with high, medium and low parasitemia, which in 1976/78 was 9.4%, 20.8% and 69.8%, respectively,changed to 4.4%, 12.9% and 82.7%, respectively, in 1988/91
