AbstractObjectives To report oropouche virus (OROV) infections in asymptomatic blood donors who attended HEMORIO. Methods The BIO-MANGUINHOS MAYV/OROV Molecular Kit was used to screen samples from asymptomatic blood donations collected in Recreio dos Bandeirantes (February 10th, 2025) and Barra Mansa (April 29th, 2025), both located in Rio de Janeiro State. The samples were subsequently sent to the National Reference Laboratory for Arboviruses at the Evandro Chagas Institute (Pará State) for confirmatory molecular testing and genomic characterization using high-throughput sequencing (HTS). Results OROV RNA was detected in samples HRIO-1 and HRIO-3, with cycle threshold (Ct) values of 39.58 and 28.99, respectively, in a pool of six plasma samples. HTS using a probe-enrichment approach enabled the recovery of one complete OROV genome from the HRIO-3 sample. Phylogenetic analysis exhibited clustering within the AMACRO II clade, forming a subclade with sequences from Rio de Janeiro, Espírito Santo, and Pernambuco. Conclusions To the best of our knowledge, this is the first study capable of detecting and genomic characterizing, through whole-genome sequencing, an OROV RNA that infects an asymptomatic blood donor in Southeastern Brazil.
Alvarez et al. (2026) studied this question.