Prevalence analysis of Chagas disease by age group in an endemic region of Brazil. Possible scenario of active vectorial transmission.

Abstract

BackgroundChagas disease (CD) is an infectious disease that predominantly affects poor and vulnerable populations. The last estimate conducted by the WHO in Latin America regarding the prevalence of CD occurred more than 10 years ago. However, there is a scarcity of data assessing the magnitude of CD in populations residing in considered high-risk regions. Thus, the objective of the present study was to assess the seroprevalence of CD in an endemic region in Northern Minas Gerais through serological screening. MethodsThis is a prevalence study conducted in the municipalities of Catuti, Mato Verde, Mirabela, Montes Azul, and São Francisco, Minas Gerais, Brazil. Data collection took place between December 2021 and December 2022, involving a questionnaire with closed-ended questions. The variables analyzed included the serological test results, stratified age groups, health indicators and housing conditions. FindingsAmong the 2978 participants included 272 individuals (9·1%) tested positive for CD serology. In the age group of 4 to 14 years, the prevalence of positive serology was 0·8% (95% CI 0·16 – 1·43), in the age group of 15 to 49 years, the prevalence of positive serology was 5·5% (95% CI 4·20 – 6·83) and in the age group of 50 years or older, the prevalence of positive serology for CD was 18·8% (95% CI 16·48-21·11). Among the participating municipalities, Mato Verde had the highest prevalence of positive serology for CD (17%). Those participants aged 4 to 14 years with positive serology for CD, first-degree relatives were invited to undergo serological testing. It was possible to collect samples from relatives of all participants in this age group. However, none of the relatives tested positive serologically. InterpretationThis study identified a 9·1% prevalence of individuals affected by CD who were unaware of their condition. In addition, having infected children in the 4 to 14 age group with mothers with negative serology would rule out congenital transmission of the disease. FundingThe research listed in this publication was updated by the National Institutes of Health under award number U19A1098461-06; U1AI1168383. The content is the sole responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.