Morbidade da doença de Chagas: IV. Estudo longitudinal de dez anos em Pains e Iguatama, Minas Gerais, Brasil

Abstract

An evolutive study of the "case-control" type was carried out in an endemic area of Chagas' disease in Minas Gerais State, Brazil, using two cross-section evaluations with an interval of ten years between them (1974-1984). Patients were paired for sex and age. In the first cross-section study 264 pairs one with a positive serology and the other with a negative serology for T. cruzi antibodies were included. In the second evaluation, ten years later, 235 patients among those with previous positive serology and 216 with negative serology were located, but only 110 pairs could be recomposed and reexamined (clinical examination, ECG and Rx of the heart and esophagus). The incidence of chagasic cardiopathy in the cases with positive serology but previously assymptomatic was 38.3% during the ten year period. On the other hand there was a deterioration in 24% of the patients with chagasic cardiopathy since the first examination. Considering all clinical forms of the disease in 34.5% of the patients the clinical situation deteriorated, in 57.3% there was no change and in 8.2% the situation improved. The general mortality in the period was 23% in the chagasic group and 10.6% in the control group, but the lethality by cardiopathy was 17% in chagasic group and only 23.3% in the control group. The mortality was twice as high in males than in females, mainly in the age group from 30 to 59 years.

Electrocardiographic findings in Mexican chagasic subjects living in high and low endemic regions of Trypanosoma cruzi infection

“…Although, it has been suggested that reinfection may play a role in the evolution of Chagas disease (Avila et al 1987), in our data, we found the same frequency of ECGs alteration for both groups from low and high endemic areas. Previous longitudinal studies carried out in the chronic phase in Brazilian individuals have shown electrocardiographic changes ranging from 23% to 38% during long-term follow-up (Dias 1985, Coura et al 1985. While in a transversal study carried out in two different geographic areas in Ecuador abnormal ECG findings in seropositive subjects was between 15% to 40% (Kawabata et al 1987).…”

Chagas' heart disease

“…Several observational studies mainly conducted in endemic areas in Brazil, Argentina and Venezuela, since the early 1940s disclosed the natural history of Chagas' heart disease 7,[26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] .…”

“…Thus, no adequate identification of cardiac involvement is usually provided in most of the rural-based studies [27][28][29][30][31][32][33][34][35][36][37] . Conversely, in hospital-based studies the heart disease is usually well characterized, but their results can not be extended to the whole spectrum of the chagasic population 8,[38][39][40][41] .…”

“…Few case-control follow-up studies have been reported in endemic areas 7,36,37 . In central Brazil 36 , two crosssectional clinical assessments spanning 10 years (1974 to 1984) were carried out including 12-lead ECG and radiological evaluation of heart size.…”

“…In central Brazil 36 , two crosssectional clinical assessments spanning 10 years (1974 to 1984) were carried out including 12-lead ECG and radiological evaluation of heart size. Serum positive patients and controls were matched by age and gender.…”