Detecting Arboviruses Through Screening Asymptomatic Blood Donors in Rio de Janeiro/Brazil During a Dengue Outbreak

Arthropod-borne viruses (arboviruses) dengue (DENV), chikungunya (CHIK), and Zika (ZIKV) have been responsible for a high number of outbreaks worldwide. However, their screening in blood donors is not mandatory, and asymptomatic cases might act as an important cause of virus transmission via transfusion. A study was conducted to assess the presence of DENV (serotypes 1-4), ZIKV, and CHIKV in pooled samples (pool size: six) from asymptomatic blood donors. A total of 9463 plasma pools, corresponding to 56,778 blood donations from asymptomatic blood donors who attended donor sessions at HEMORIO and other blood centers in Rio de Janeiro and Espírito Santo, was submitted to automated nucleic-acid extraction and PCR amplification using ZC D-<i>Tipagem</i> molecular assay (Bio-Manguinhos). In general, a pool prevalence of 1% (95/9463) and a donor prevalence of 0.17% (95/56,778) were observed. January and February 2024 had a total of 62 positive pools out of 95 (65.3%). Targets DENV-1 and -2 had a higher prevalence in the studied months-early summer-with 24 and 28 positive pools, respectively. ZC D-<i>Tipagem</i> molecular assay was able to detect the best-known arboviruses circulating in asymptomatic blood donors; this study suggested that ZIKV, CHIK, and DENV are circulating in asymptomatic blood donors before blood donations and can be transmitted to blood transfusion recipients.