[The behavior of Trypanosoma cruzi parasitemia in chronic chagasics over 13 years].

The parasitemia of 202 chronic chagasics was studied for approximately 13 years by repeated 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, which 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.