[The influence of the parasitemia on the evolution of the chronic Chagas' disease].

During 13 years, 190 individuals with chagasic infection were submitted to clinical and parasitological examinations to investigate the relationship between parasitemia and the evolution of chronic chagasic infection. Fifty-six patients with positive xenodiagnosis and 134 with negative exams were compared from 1988 to 91, it was found that 22 (39.3%) and 50 (37.3%), respectively, presented disease progression. The parasitemia was stratified into high, medium and low and the relation with the disease evolution showed that 5 (62.5%), 10 (41.7%) and 57 (36.1%), respectively, presented progressive disease, though without a statistically significant difference (p>0.05). When 20 patients with persistent parasitemia in 1976/91, were compared with 59 with negative xenodiagnosis, a progressive evolution was observed in 6 (30%) and 17 (28.8%), respectively. Comparing six patients with high parasitemia and 59 with negative exams, it was verified that 3 (50%) and 17 (28.8%), respectively, showed progressive disease, but this was not statistically significant, (p>0.05). Mean age with high, medium and low parasitemia were 39.6, 45.3 and 41.5 years, respectively, (p>0.05). Mean age in patients showing progressive, unaltered and regressive evolution was 46.4, 39.8 and 32.6 years, respectively, with a statistically significant difference between progressive and regressive evolution (p<0.05). It is suggested that high parasitemia did not have an influence on the evolution of the chronic infection.