Morbidade da doença de Chagas em pacientes autóctones da microrregião do Rio Negro, Estado do Amazonas

Abstract

RESUMO ABSTRACTIntroduction. A seroepidemiological and clinical study was conducted on 152 autochthonous individuals living in the district of Barcelos, State of Amazonas, to evaluate the seroprevalence of Chagas infection and morbidity of Chagas disease. Methods. The serological tests used were indirect immunofluorescence, conventional and recombinant ELISA and immunoblot (Tesa-blot). Thirty-eight patients were considered seropositive; 31 were considered serodoubtful; and 83 were considered seronegative. The 38 seropositive cases were paired with 38 seronegative controls of the same age and sex, and underwent epidemiological and clinical evaluations, electrocardiograms and echocardiograms. Twenty-nine pairs underwent radiological examinations of the esophagus. Results. Seropositivity was 19.9 times more frequent among workers gathering plant materials from the forests and 10.4 times more frequent among piassaba gatherers. Eighty six point seven percent of the seropositive individuals recognized the genus Rhodnius as the local vector, while only 34.2% of the seronegative individuals recognized this. The EKG was abnormal in 36.8% of the seropositive individuals and in 21.5% of the seronegative individuals, while the echocardiogram showed abnormalities in 31.6% of the seropositive and 18.4% of the seronegative individuals. Precordialgia and palpitation were more frequent among the seropositive individuals. Clinical evaluation on the digestive system and X-ray on the esophagus did not show significant abnormalities. Conclusions.

Serological survey for Chagas disease in the rural areas of Manaus, Coari, and Tefé in the Western Brazilian Amazon

“…The estimated rate of chronic chagasic infection in the population of the studied area reinforces other studies carried out in Amazonia, where the prevalence of chagasic infection varies from 1.9% to 6.8% [5][6][16][17]19,21 . Although we have registered more cases of CD in Manaus, the frequency of Chagas disease in Tefé was slightly higher; however, we could not make comparisons because of the difference in the time reference, and the population included in the study in Tefé was numerically smaller than that in Manaus.…”

“…However, the reported 60% of patients with CD in the age group above 40 years may indicate old cases with the possibility of progression to symptomatic chronic forms, drawing attention to the importance of diagnosis through the conduct of serological surveys of cases. Such surveys demonstrate the circulation of the disease in municipalities, as has been observed in the municipality of Barcelos, where the disease has already been circulating for some time 17 . We can see that the anti-T. cruzi antibody reaction is cumulative with age, possibly due to longer exposure to the infective agent during the course of a lifetime.…”

“…In Barcelos (Rio Negro/AM), a prevalence of 2.8 to 5% [16][17]37 has been estimated. The main reasons for these numbers are the subsistence activities of most inhabitants, such as gathering piassava (Leopoldinia piassaba), a palm tree species with high occurrence of the Rhodnius brethesi, a triatomine T. cruzi vector in the area, also known as piassava lice.…”

“…In 1971, the occurrence of T. cruzi from naturally infected triatomines, which were implicated in the transmission of the disease, was reported in the City of Manaus 15 . Since then, there have been suspected or confirmed acute and chronic CD cases in this state, occasionally [5][6][16][17][18] .…”

“…Regardless of such numbers, the infection dynamics has not been well established yet, as there are no records of the domiciliation of vectors. Currently, the vast majority of cases in the area are related to oral route transmission and associated with the ingestion of palm tree fruit juice, besides the occurrence of an outbreak in the acute phase of the disease 4,17,20 . The detection of occasional clinical CD cases in this area provides data that allow the implementation of actions against its dissemination in the area [10][11] .…”