EXPOSURE TO OROPOUCHE VIRUS IN PREGNANCY

Oropouche virus (Oropouche orthobunyavirus – OROV) is an arbovirus of the Peribunyaviridae family, endemic in many South and Central American countries, spread through the bites of infected midges and mosquitoes.

Clinical features of OROV disease are similar to those observed in people with other arboviruses (such as dengue, West Nile, yellow fever and Zika), and include abrupt onset fever with headache (often severe), rigors, myalgia, arthralgia, photophobia, dizziness, retroorbital or eye pain, nausea and vomiting, and maculopapular rash. Neuroinvasive disease such as meningitis and encephalitis may occur in severe cases. Symptoms typically start 3 to 10 days post-infection, and mostly resolve within 7 days, usually without long-term effects.

Retrospective serum sample investigations and case reports provide evidence of possible vertical transmission of OROV (from mother to fetus). Pregnancy outcomes in these reports include three cases of miscarriage, one intrauterine fetal death, and four live-born infants with microcephaly. Due to data limitations, it is not possible to establish OROV vertical transmission as the cause of these outcomes.

It is recommended that people travelling to affected areas should undertake standard bite prevention approaches during both day and night. There is currently no specific treatment recommended for OROV disease in pregnancy. Supportive care with rest, fluids, analgesics and antipyretics are generally recommended for most people with OROV disease (avoiding aspirin or NSAIDs in cases where dengue cannot be excluded due to a risk of bleeding). NSAIDs should also be avoided after 20 weeks of pregnancy. Further information on risks and prevention measures for travellers and health professionals is available from the National Travel Health Network and Centre (NaTHNaC).

Cases of suspected OROV disease in pregnant women from the UK who have travelled to regions where the virus is endemic should be reported to UKTIS for surveillance purposes, and should also be reported to the local UKHSA Health Protection Team to enable a public health response. Fetal medicine referral is recommended for those with proven infection or exposure to screen for microcephaly and to monitor fetal growth and wellbeing. Based on evidence acquired from congenital Zika syndrome surveillance, where congenital infection related microcephaly is observed, a severe impact on long-term neurodevelopmental and health outcomes is predicted. Discussion with UKTIS is recommended in all such cases.