Re-emerging Oropouche virus infections: insights into maternal-fetal crosstalk, coinfections, and expanding public health threats.

Oropouche virus (OROV), a re-emerging orthobunyavirus of the Simbu serogroup, is increasingly recognized as a significant arboviral threat across the Americas. Although historically underrecognized, OROV infection raises urgent concerns due to reported co-infections with other arboviruses and possible novel nonvector transmission, including vertical and sexual routes. Recent reports link OROV infection during pregnancy with fetal demise, miscarriage, and congenital anomalies in newborns. Drawing on emerging epidemiological, clinical, and virological studies, we review recent findings on maternal-fetal transmission, co-infection dynamics, and potential alternative routes of OROV spread. We highlight critical knowledge gaps in transmission mechanisms, the frequency and spectrum of adverse pregnancy outcomes, vector competence, and diagnostic challenges. Addressing these gaps will require integrated strategies across virology, obstetrics, immunology, and public health.