A Case of Vertical Transmission of Oropouche Virus in Brazil

This correspondence describes a stillbirth associated with vertical transmission of Oropouche virus (OROV) in a previously unaffected region of Ceará, Brazil. The 40-year-old pregnant woman presented with fever, headache, and myalgia at 30 weeks’ gestation, followed by fetal death. Molecular diagnostics confirmed OROV infection, excluding other arboviral and infectious causes. Minimally invasive tissue sampling revealed OROV RNA in cerebrospinal fluid, brain, lungs, liver, umbilical cord, and placenta of the stillborn male, confirming vertical transmission. Phylogenetic analysis clustered viral sequences with the BR-2019–2024 reassortant lineage, aligning with an ongoing outbreak. The case underscores pregnancy risks in emerging OROV regions and the need for surveillance expansion.

This correspondence describes a stillbirth associated with vertical transmission of Oropouche virus (OROV) in a previously unaffected region of Ceará, Brazil. The 40-year-old pregnant woman presented with fever, headache, and myalgia at 30 weeks’ gestation, followed by fetal death. Molecular diagnostics confirmed OROV infection, excluding other arboviral and infectious causes. Minimally invasive tissue sampling revealed OROV RNA in cerebrospinal fluid, brain, lungs, liver, umbilical cord, and placenta of the stillborn male, confirming vertical transmission. Phylogenetic analysis clustered viral sequences with the BR-2019–2024 reassortant lineage, aligning with an ongoing outbreak. The case underscores pregnancy risks in emerging OROV regions and the need for surveillance expansion.