[Prevalence of chagas infection in Catolândia-Bahia]

Seroepidemiological Survey of Chronic Chagas Disease in a Rural Community in Southern Bahia, Brazil, Using Recombinant Chimeric Antigens

Chagas disease (CD), caused by the parasite Trypanosoma cruzi, is a neglected tropical disease with life-threatening implications. In this study, we conducted a seroepidemiological survey to determine the prevalence and clinical profiles of CD in 217 individuals from an impoverished rural community in Southern Bahia, Brazil. The overall prevalence of CD in the studied community was 0.92%, detected through latent class analysis (LCA). Two individuals tested positive for anti-T. cruzi IgG, both being male farmers. One case was a 22-year-old man born in Camamu, with no evidence of congenital transmission, suggesting other routes of transmission such as vector-borne transmission due to migratory activities. The other case was a 69-year-old man born in São Felipe, who had lived in an adobe/brick house and had a pacemaker due to cardiac involvement caused by CD. The prevalence in this community was lower than expected, given the socioeconomic conditions and environmental factors that contribute to T. cruzi transmission. This could be attributed to the implementation of preventive measures and vector control programs by the Brazilian Government. However, continuous monitoring and surveillance are essential to sustain control efforts and detect any potential re-emergence of the disease. While the overall prevalence was low, the detection of positive cases underscores the need for continued surveillance and control measures in vulnerable populations, such as rural communities. Active surveillance, early diagnosis, and timely treatment are crucial in preventing disease progression and complications, thereby enhancing the effectiveness of screening and treatment programs.

Seroepidemiology of Chagas disease in at-risk individuals in Caraíbas, a city with high endemicity in Bahia State, Brazil

Introduction

In Brazil, an estimated 1.1 million people are infected with Trypanosoma cruzi, the causative agent of Chagas disease (CD). Despite the high number of cases, the estimated prevalence of infection per 100 inhabitants is low (0.03). However, the actual number of chronically infected individuals is still unknown. Therefore, we sought to determine the prevalence of chronic CD in at-risk individuals in Caraíbas (Bahia, Brazil) through active case finding.

Methods

A total of 572 individuals living in rural or urban areas of Caraíbas were eligible for the study. A serum sample was collected from 226 individuals, and the diagnosis performed according to international guidelines.

Results

The overall prevalence of anti-T. cruzi IgG was 4.42%. The median age of anti-T. cruzi IgG-positive individuals was 54.5 years, and the female-to-male ratio was 1.5:1. The prevalence of anti-T. cruzi IgG was similar in rural (4.29%) and urban areas (4.65%).

Discussion

Compared with national estimates, we concluded that Caraíbas had a high prevalence for chronic CD and a high risk for persistent transmission. Through our study, it was possible to monitor individuals who were unaware of their clinical condition, thus improving their quality of life.

Prevalence of Chagas disease in Brazil: a systematic review and meta-analysis

Chagas disease is a major public health problem in Brazil and Latin America. During the last years, it has become an emerging problem in North America and Europe due to increasing international migration. Here we describe the prevalence of Chagas disease in Brazil through a systematic review. We searched national and international electronic databases, grey literature and reference lists of selected articles for population-based studies on Chagas disease prevalence in Brazil, performed from 1980 until September 2012. Forty-two articles with relevant prevalence data were identified from a total of 4985 references. Prevalence ranged from 0% to 25.1%. Most surveys were performed in the Northeast region, especially in the state of Piauí. We observed a high degree of heterogeneity in most pooled estimates (I(2)>75%; p<0.001). The pooled estimate of Chagas disease prevalence across studies for the entire period was 4.2% (95% CI: 3.1-5.7), ranging from 4.4% (95% CI: 2.3-8.3) in the 1980s to 2.4% (95% CI: 1.5-3.8) after 2000. Females (4.2%; 95% CI: 2.6-6.8), >60 year-olds (17.7%; 95% CI: 11.4-26.5), Northeast (5.0%; 95% CI: 3.1-8.1) and Southeast (5.0%; CI: 2.4-9.9) regions and mixed (urban/rural) areas (6.4%; 95% CI: 4.2-9.4) had the highest pooled prevalence. About 4.6 million (95% CI: 2.9-7.2 million) of people are estimated to be infected with Trypanosoma cruzi. The small number of studies and small-scale samples of the general population in some areas limit interpretation, and findings of this review do not necessarily reflect the situation of the entire country. Systematic population-based studies at regional and national level are recommended to provide more accurate estimates and better define the epidemiology and risk areas of Chagas disease in Brazil.