In Mambaí (GO), 303 people with positive serology for T. cruzi were subjected to three xenodiagnoses, using two bugs species, Dipetalogaster maximus and Triatoma infestans in order to study subpatent parasitemia. Two hundred and ten (69,3%) had a positive xenodiagnosis. The first test detected parasites in 125 (41,2%), the second in 59 (19,5%) and the third in a further 26 (8,6%) individuals. In 21 children up to nine years of age 90,5% were positive. Patients were classified in three groups depending on the intensity of infection detected in the bug faeces. Using these criteria, 28 (9,2%) had high parasitemia, 73 (24,1%) had moderate parasitemia and 202 (66,7%) low parasitemia. High and moderate parasitemia were detected during the first two examination. Of the low parasitemia group 22,8% were positive in the first, 41,1% on the second and 54% on the third examination. The value of repeated xeno-diagnosis, specially in people with small numbers of circulating parasites, is indicated by the date presented.
Xenodiagnosis; Parasitemia; Chagas disease; Parasitological diagnosis; Dipetalogaster maximus