Analysis of the seroprevalence of and factors associated with Chagas disease in an endemic area in northeastern Brazil

Introduction: Chagas disease (CD) is currently considered a neglected disease; hence, identifying the factors associated with its high prevalence is essential. This study aimed to identify the seroprevalence of and the possible factors associated with CD in inhabitants of the City of Limoeiro do Norte, northeastern Brazil. Methods: Between April and November 2013, blood collection was conducted and a semi-structured questionnaire was administered. Blood samples that showed positive or possible serology for anti-Trypanosoma cruzi antibodies based on indirect immunofluorescence, hemagglutination indirect, and an enzyme-linked immunosorbent assay were analyzed. Associations between CD positivity and the study variables were analyzed using prevalence ratios (PR) with 95% confidence intervals (CI). Results: A total of 812 individuals were analyzed, of which T. cruzi seropositivity was determined in 4.2% (34 individuals). Sociodemographic variables showing a significant association with T. cruzi positivity included age > 50 years (PR = 27.6; 95% CI = 6.66-114.4), elementary level education (PR = 5.15; 95% CI = 1.83-14.47), and retirement (PR = 7.25; 95% CI = 3.72-14.14). Positivity for T. cruzi was 6.17 times higher in those who had a history of living in rammed earth houses compared with those who did not (95% CI = 2.19-17.37). There was no evidence of vertical transmission in the individuals studied. Among the individuals infected with T. cruzi, the majority reported having a comorbidity (p < 0.01). Conclusions: This study demonstrated the seroprevalence of CD and identified factors associated with a high prevalence of CD.