Prevalência da infecção assintomática por Leishmania em doadores de sangue de área endêmica para Leishmaniose Visceral

Abstract

Introduction: Visceral Leishmaniasis (VL) was traditionally considered a rural disease in northeast Brazil. However, since the 1990s there has been an increase in its incidence in urban areas, accompanied by clinical changes such as the appearance of asymptomatic infections. Identifying these asymptomatic infections poses a challenge for VL control programs. Blood banks can reflect the epidemiological context, as well as assist in the identification and monitoring of these cases. Aim: To estimate the infection rate of Leishmania in blood donors from an endemic area for VL. Method: This is a cross-sectional study conducted at the Dalton Cunha Blood Center in Rio Grande do Norte. The investigation was carried out with voluntary blood donors during the donation process from May 7, 2020, to November 19, 2021. For the volunteers who consented to provide data, sociodemographic, environmental, and health history information was collected. Simultaneously, 10ml samples of venous blood were collected from all participants and subjected to ELISA serological testing for Leishmania Soluble Antigen. Serologically positive samples were further tested using qPCR for Leishmania DNA detection. Statistical analysis of the data was performed using the R software, in which a bivariate logistic regression model was applied to evaluate the association between Leishmania infection and the studied variables. Results: A total of 1,307 blood donors were included in the study and screened for Anti-Leishmania antibodies. The sociodemographic characteristics of the participants were recorded during sample collection. Male donors constituted 63% (n=827) of the participants. The ages of the donors ranged from 17 to 68 years, with a mean age of 35.2 years and a standard deviation of 17.01. We identified 115 (8.8%, 95% CI: 7.4%-10.5%) blood donors positive for Leishmania infection by ELISA SLA, while 37 (32.2%, 95% CI: 24.3%-41.2%) of seropositive donors were positive for Leishmania infection by PCR KDNA7. Significant statistical differences were observed between the infection profile and travel history in the last 12 months (p=0.003) and the non-educated category (p=0.01). The seropositive donors resided in 15 municipalities of the state. The municipality of Natal concentrated the majority of positive cases (n=70), demonstrating that the positivity rate in this population is 10.1% (n=70, 95% CI: 8.1-12.6). Conclusion: Blood donors from endemic areas for Visceral Leishmaniasis (VL) may be infected with Leishmania, consequently supporting the hypothesis that the assessment of blood donors from endemic areas can serve as sentinels to estimate the magnitude of asymptomatic infection. These data also indicate a potential risk of Leishmania transmission through blood donation, as already documented in other endemic areas for Visceral Leishmaniasis.