(P-BC-30) Epidemiological Profile and Factors Associated with Seropositivity for Chagas Disease in Blood Donors: An Analysis of 148.378 Cases (Perfil epidemiológico e fatores associados à soropositividade para doença de Chagas em doadores de sangue: análise de 148.378 casos)

Chagas disease is caused by the protozoan Trypanosoma Cruzi, and generates several harms to its carrier, with the acute phase being characterized more with nonspecific symptoms such as fever, malaise and lack of appetite; and the chronic phase such as Chagas and megacolon cardiomyopathy. Thus, due to the great relevance that Chagas disease still has today, the objective of this study was to analyze the prevalence of Chagas disease in blood donors and identify demographic and socioeconomic factors associated with seropositivity in the southern region of the country.

Study

Design/Methods: Retrospective study of 2012 and 2022 in hemotherapy in the north of Rio Grande do Sul, Brazil, for the investigation of serological markers of Chagas disease, using ELISA and chemiluminescence. Positive samples were reanalyzed and confirmed by IFI IgG/IgM.

Results/Findings:

Of 148,378 donations, 206 (0.14%) were positive. Most of the positives were men (54.4%) and young (< 30 years: 35.0%). Schooling varied: elementary school (36.9%), high school (42.2%), higher education (20.9%). Among the civil states, 50.0% were single/widower, 44.7% married, and 5.3% divorced/separated. In the first donation, 51.5% were reactive, with 71.8% returning to the second collection, resulting in 41.9% reagents. IFI tests identified two reagents for IgM and 18 for IgG. Table 1 shows a significant association between age/schooling and positive serology in the first donation (p=0.039/0.013). There was a significant association between age group and false positive for seropositivity of Chagas disease (χ2 = 5.046p p = 0.025). Individuals under 30 years of age had a higher risk of false positive (OR = 2.556; 95%CI = [1.109; 5.887]).

Conclusions:

The prevalence of Chagas disease in endemic areas of northern Brazil was 0.33% (Costa et al., 2020), while in the South a rate of 0.27% was reported (Bianchi et al., 2022), results higher than those of this study, which pointed to a prevalence of 0.14%, aligning with Hemoprod (2020) which indicated 0.10% in the same region. Lopes et al. (2015) and Cogo et al. (2014) found a positive correlation between age and seropositivity for Chagas, with no significant differences by sex, similar to this study. The rate of return for serological confirmation was 71.8%, close to the 61.8% of Costa et al. (2020). The high incidence of false positives (77.18%) in confirmation is attributed to the sensitivity of the tests, as observed by Costa et al. (2020). The study identified the incidence of Chagas in donations, highlighting the importance of surveillance. A higher prevalence was observed in men, young and less educated, indicating the need for educational campaigns. Reactivity in first donation suggests recent infections, highlighting the need for confirmatory tests.