Urban arbovirus exposure in blood donations from an endemic area of Brazil.

Background and Objectives: In Brazil, urban arboviruses, such as dengue virus (DENV), Zika virus (ZIKV) and chikungunya virus (CHIKV), constitute a major public health problem, and due to their endemicity and asymptomatic cases, they pose a potential threat to blood donations. Rio de Janeiro (RJ), Brazil, has been impacted by extensive DENV epidemics over the last 30 years and, after 2015, by CHIKV and ZIKV. Materials and Methods: Urban arboviruses DENV, ZIKV and CHIKV were investigated in blood donations (n = 778) at the State Institute of Hematology, HEMORIO (RJ) from 2019 to 2022 by serological and molecular methods. Results: An overall arbovirus exposure was observed in 26.1% of the blood donations. Anti‐DENV IgM was detected in 4.0% of samples and two donations were DENV NS1 positive. Positive anti‐CHIKV IgM was observed in 4.7% of the donations. Co‐detection of anti‐CHIKV IgM and anti‐DENV IgM was observed in 1.0% of donors, and CHIKV prevalence was 21.3%. All blood donations tested were negative for the DENV, ZIKV and CHIKV RNA. Conclusion: IgM seroprevalence to the arboviruses analyzed here is an indicator of recent infection in asymptomatic donors, showing that the population of blood donors can be a vehicle for new infections, especially during epidemic periods. [ABSTRACT FROM AUTHOR]