A recently published case series study examined the epidemiologic, clinical, and obstetric outcomes of pregnant women with Oropouche fever in Espírito Santo, Brazil, from March 28 to December 22, 2024. Among 4’062 reported cases, 73 involved pregnant women. Of 15 completed pregnancies, 14 resulted in live births and one in spontaneous abortion. Placental reverse transcription PCR tests were positive for Oropouche virus RNA in 5 infections in the third trimester. Two infections occurred in the first trimester, resulting in 1 spontaneous abortion and 1 live birth with corpus callosum dysgenesis. Among 13 third-trimester infections, one case showed possible intrapartum transmission with clinical symptoms in the neonate, while the others were asymptomatic. No anomalies were found in third-trimester infections.
The authors suggest that these findings indicate potential vertical transmission of the Oropouche virus and an association with spontaneous abortion or malformation. For details, see publication.
Entire Brazil: as of 19 March 2025, a total of 6’683 confirmed cases of Oropouche virus disease, with one death currently under investigation, have been reported in Brazil.
Prevention: The best way to protect yourself from Oropouche virus infection is to prevent insect bites 24/7 (also against other mosquito-borne diseases such as Dengue, Zika, Chikungunya and malaria), see factsheet mosquito bite prevention.
Pregnant women and women planning to become pregnant should be provided with comprehensive information during pre-travel counselling where Oropouche virus transmission has been documented, including outbreaks reported, and the potential risks of miscarriage, fetal malformation or death.
In the event of increased Oropouche transmission (declared as an Oropouche outbreak according CDC Level 2 Travel Health Notice for Oropouche - as of 2 April 2025: state of Espírito Santo in Brazil and Dariéen Province in Panama), the Swiss Expert Commission for Travel Medicine recommends:
- Pregnant women should re-consider non-essential travel
- If travel is unavoidable, strictly adhere to insect prevention measures (see LINK) and talk to your health care provider.
- To avoid sexual transmission: males should consider using condoms during travel and up to 2 months after return.
In case of fever, malaria should be always ruled out by blood tests.