Key points
- Oropouche virus is spread to people primarily by the bite of infected biting midges. Some mosquitoes can also spread the virus.
- There are no vaccines to prevent or medicines to treat Oropouche.
- The best way to protect yourself from Oropouche is to prevent bug bites.
- It is possible that Oropouche might spread through sex, but it has not yet been reported. Consider the recommendations below.

Overview
Oropouche virus is spread to people primarily by the bite of an infected biting midge. Biting midges are small flies, often called "no-see-ums." It can also be spread by some mosquitoes, including Culex quinquefasciatus mosquitoes, which can also spread West Nile and St. Louis encephalitis viruses.
There are no vaccines to prevent or medicines to treat Oropouche. The best way to protect yourself from Oropouche is to prevent bites from biting midges and mosquitoes in areas where the virus is known to occur, including several countries in South America, Central America, and the Caribbean. Learn where are occurring in the Americas.
Prevention tips
Use insect repellent
Use Environmental Protection Agency (EPA)-registered insect repellents. When used as directed, EPA-registered insect repellents are proven safe and effective. Look for EPA-registered repellents labeled for flies, biting flies, or Culicoides (biting midges, punkies, granny nippers, and no-see-ums). Prevent bites while traveling if you'll be going to an area with Oropouche virus.
Use window and door screens
- Many commonly used window and door screens do not have holes small enough to prevent biting midges from getting inside.
- To prevent biting midges from entering your home, look for mesh screens measuring 20x20.
Use a fan when outdoors
When possible, use fans to help blow biting midges away when spending time outdoors.
For blood donors
- If you have recently been diagnosed with Oropouche, let your blood center know. Blood donors must be healthy and well on the day of donation, and in some people it might take time to clear the virus from their blood. Until more is known, consider waiting 4 weeks after your illness resolves to donate blood.
- If you were diagnosed with Oropouche shortly after giving blood, tell your blood center.
Preventing possible spread through sex
It is possible that Oropouche virus might spread through sex, but it has not yet been reported. Until we know more, the recommendations below can help travelers to areas with a Travel Health Notice for Oropouche make informed decisions about their health.
Testing semen, vaginal fluids, or urine is not available or recommended to determine how likely a person is to spread Oropouche virus through sex.
Recommendations
Any traveler who is concerned about Oropouche
If you traveled to an area with a and are concerned about possibly spreading the virus through sex, consider using condoms or not having sex during travel and for 6 weeks after travel.
Travelers with symptoms of Oropouche
If you traveled to an area with a Travel Health Notice for Oropouche and experienced symptoms that might be caused by Oropouche virus during or within 2 weeks after travel:
- Talk to your healthcare provider about getting tested for Oropouche.
- Consider using condoms or not having sex for at least 6 weeks after symptoms began.
Males diagnosed with Oropouche
Use condoms or do not have sex for at least 6 weeks from the start of your symptoms.
Females diagnosed with Oropouche
We do not have enough data to make a firm recommendation. However, if you are concerned, consider using condoms or not having sex during travel and for 6 weeks after travel.
Semen donors diagnosed with or possibly exposed to Oropouche virus
Until more is known, wait at least 6 weeks from the start of your symptoms to donate. If you had no symptoms, consider waiting 6 weeks after returning from travel.
- Talk to your donation center about your eligibility to donate.
- Review for more information on eligibility to donate human cell, tissue, and cellular and tissue-based products.