Seroepidemiology of Trypanosoma cruzi infection in the semiarid rural zone of the State of Rio Grande do Norte, Brazil

Abstract

<jats:p>INTRODUCTION: A seroepidemiological survey was carried out to evaluate Trypanosoma cruzi infection in an endemic area of the State of Rio Grande do Norte, Brazil, involving rural residents. METHODS: Sixteen municipalities were randomly selected, 15 from the west mesoregion and one from the central, with an estimated population of 83,852 individuals. A total of 1,950 blood samples were collected in the west mesoregion and 390 in Caicó. Anti-T. cruzi antibodies were detected using the Chagatest® ELISA HAI-hemagglutination kits and indirect immunofluorescence. As sera presented indeterminate results, TESAcruzi® western blot was performed to confirm reactivity. RESULTS: An estimated seroprevalence of 6.5% was determined for the west mesoregion and 3.3% for Caicó. Seropositivity rises progressively with the age of individuals, up to 40 years in Caicó and up to 50 years in the west mesoregion. Only educational level and knowledge regarding the triatomine were associated with seropositivity. No seroreactive individuals under 18 years of age were identified. CONCLUSIONS: Infection by T. cruzi remains high and is concentrated in municipalities in the central western area of the west mesoregion; however, evidence suggests a decline in vector transmission in this mesoregion and in Caicó. Epidemiological variables appear not to influence seropositivity, with the exception of education and knowledge concerning the triatomine, among seroreactive individuals from the west mesoregion.</jats:p>

Chagas disease: morbidity profile in an endemic area of Northeastern Brazil

“…More recent data support an estimated seroprevalence of 6.5% for chagasic infection in the Western mesoregion of RN, although that study did not examine the clinical forms of ChD (12) . Therefore, the present study aimed to characterize the different clinical forms of ChD, its evolution among seroreactive individuals from different municipalities in western RN, and its association with disease severity.…”

“…The present study was performed in the West mesoregion, which covers >40% of RN's surface area (53,077.3km²) (Figure 1). This area was selected because a previous seroepidemiological survey was performed in this region during 2007-2009, and reported an estimated ChD prevalence of 6.5% (12) .…”

“…However, only 186 individuals (23-78 years old) were ultimately included, as various patients were excluded due to disabilities, unwillingness to be examined, and other heart pathologies (e.g., ischemic, valvular, and hypertensive heart disease). Among the 186 included individuals, 83 individuals (38 men and 45 women) had participated in the previous seroepidemiological survey (12) , and 103 individuals (54 men and 49 women) had spontaneously demanded testing at the ChD outpatient clinic of the State University of Rio Grande do Norte. The patients who spontaneously demanded testing generally presented with two or more previous reactive serological tests for T. cruzi (e.g., at blood banks or primary health centers), and had been instructed to seek treatment at our outpatient clinic.…”

Characteristics of Triatomine infestation and natural Trypanosoma cruzi infection in the State of Rio Grande do Norte, Brazil

“…A recent seroepidemiological survey showed high seroprevalence for municipalities in the west and central mesoregions of the State of Rio Grande do Norte (RN) (28) , and genotyping studies identified T. cruzi I (TcI) in T. brasiliensis and TcIII (formerly called TcIIc) in armadillos (29) , TcI and TcII in humans, TcII and TcIII in T. brasiliensis, and TcIII in P. lutzi (15) .…”

“…About 90% of the territory represents arid and semiarid climates, where the predominant biome is the Caatinga, characterized as containing thorny shrubs, irregular structure, and partially uncovered soil. This study was conducted in the municipalities of Apodi, Caraúbas, Governador Dix-Sept Rosado, Lucrécia, Mossoró, Severiano Melo, São Miguel, Caicó, and Serra Negra do Norte in the West and Central mesoregions (Figure 1), which were selected in reference to the seroepidemiological survey conducted between 2007 and 2009 (28) .…”