Oropouche virus disease: information for travellers and health professionals

Information on risks and prevention measures for travellers and health professionals

• This updates the news item of 23 April 2025

Oropouche virus disease is an infection caused by Oropouche virus (OROV). Before late 2023, OROV was reported in Brazil, Bolivia, Colombia, Ecuador, French Guiana, Haiti, Panama, Peru, Trinidad and Tobago and Venezuela. Most cases were reported near the Amazon rainforest and in the Caribbbean [1].

In 2024, locally acquired cases of OROV disease were reported in areas with no previous history of infection and this virus is now circulating in many parts of Central and South America, and the Caribbean [1, 2]. In 2024, a total of 16,239 confirmed cases, including four deaths, were reported in the Americas Region [2].

Brazil was the most severely affected country, with all 24 Brazilian states reporting cases, but outbreaks were also confirmed in Barbados, Bolivia, Colombia, Cuba, Dominican Republic, Ecuador, Guyana, Panama and Peru. A number of imported OROV disease cases outside these outbreak countries were also reported, including cases in European travellers who visited risk countries [1-3]. In March 2025, locally acquired cases of OROV disease were reported in Venezuela [4].

On 25 July 2025, three imported OROV disease cases were confirmed in United Kingdom (UK) residents who visited Brazil earlier in 2025 [5].

OROV is transmitted (spread) to humans mainly through the bite of an infected midge (Culicoides paraensis) found in the Americas and the Caribbean (but not a type of midge found anywhere in the UK). Some mosquitoes can also transmit OROV [1, 2].

Symptoms of OROV disease begin four to eight days after an infective bite. The illness starts suddenly, usually with a fever, chills, headache, joint pain and muscle aches. Symptoms typically last for up to seven days. However, some people may develop more severe disease, including meningitis or encephalitis.

In October 2024, the Pan American Health Organisation (PAHO) reported possible cases of OROV being passed from mother-to-baby during pregnancy (vertical transmission) in Brazil and Cuba [6]. Based on further data from Brazil and Cuba, cases of vertical transmission of OROV during pregnancy have now been confirmed [2, 7, 8, 9].

However, it is not known how frequently vertical transmission occurs during pregnancy and if the timing of OROV infection in pregnancy increases risk of an adverse outcome [6]. Work to gain a more detailed understanding of the risks of OROV infection during pregnancy continues [1, 7, 8].

In September 2024, Cuba reported three cases of Guillain-Barré syndrome associated with OROV disease [6, 10].

In October 2024, a scientific report explained that for the first time OROV had been found in the semen of a returned traveller with OROV disease [11]. This raises concern about the possible risk of sexual transmission, which has been reported with other viruses such as Zika virus disease and Ebola [12]. This also has potential implications for sperm donation and assisted reproductive technologies [11]. To date, no cases of sexual transmission of OROV have been reported [1, 12].

There are no specific medicine or vaccines to prevent OROV disease, but the risk of infection can be minimised by following bite avoidance measures when visiting areas with the infection. Treatment for OROV disease is supportive (management of symptoms).

Advice for travellers

Before you travel

Check our Country Information pages to research general health risks, prevention advice and any vaccine recommendations or malaria advice for your destination. Outbreaks of OROV will be reported on our Outbreak Surveillance database.

If you are planning to visit countries reporting diseases spread by mosquitos and insects, including OROV, get travel health advice from your GP, practice nurse, a travel clinic or a pharmacy offering travel services. Ideally arrange this at least four to six weeks before you travel, but if you are travelling at short notice, last minute advice is still helpful.

Due to concerns about mother-to-baby transmission in pregnancy, a cautious approach is recommended, given the high potential impact. As OROV can potentially pass from a pregnant woman to their unborn baby, and infection in pregnancy has been linked to stillbirth and birth defects, pregnant woman, and anyone planning a pregnancy, should discuss the suitability of travel and the potential risk with their health care provider. If travelling in an affected area, insect bite prevention recommendations should be strictly followed [13].

In addition, other diseases like Zika virus disease and malaria may be a risk in areas where OROV disease is reported.

While you are away

There is no vaccine or medicine to prevent OROV infection. The only way to try to prevent infection is by minimising bites from midges and mosquitoes (this also helps protect against other insect and tick spread infections) or by avoiding visiting regions with a known or potential risk for OROV.

Try to stay in places with air conditioning or that use window and door screens with mesh measuring 20x20 designed to keep biting midges outside [14].

Standard bed nets are less effective against biting midges, as these insects are small and can pass through the netting. Insecticide treated fine mesh bed nets and chemical insecticides sprayed inside and outside can help deter midges.

As a precaution, due to the recent finding of OROV in semen, travellers and their partners concerned about possibly spreading OROV through sex, can consider using condoms or not having sex during travel and for six weeks after returning from travel.

Get urgent advice from a health professional if you develop symptoms while you are abroad.

When you return

If you or anyone in your family become unwell with symptoms such as high fever, chills, headache, joint pain and muscle aches following overseas travel, you should get urgent medical advice.

Pregnant women should also tell their midwife or doctor if they have travelled to risk areas.

Until more is known, due to the recent finding of OROV in semen, travellers and their partners concerned about possibly spreading OROV through sex, can consider using condoms or not having sex during travel and for six weeks after returning from travel [13].

It is important to tell your medical provider about any recent travel abroad.

Advice for health professionals

Carry out a comprehensive risk assessment with any traveller planning to visit destinations with OROV disease, as other infections such as dengue, Zika virus disease and malaria may also be reported in the same region. Pregnant women should be informed of the potential risks that these infections may present.

Health professionals should remain alert for travellers returning from areas where there is a risk from arboviral infections. Symptoms of OROV infection are similar to other arboviral infections reported in the Americas, including dengue, chikungunya or Zika virus disease.

As for all arboviral infections, if OROV disease is suspected you should seek clinical advice initially from a local microbiology, virology or infectious disease consultant.

Testing for acute OROV disease is available in the UK via the UK Health Security Agency (UKHSA) Rare and Imported Pathogens Laboratory (RIPL) in Porton Down. Following the increase in cases in the Americas in 2024, RIPL is undertaking active surveillance by testing samples submitted for dengue diagnosis when a symptomatic returned traveller visited an OROV affected region and tested negative for dengue [15].

For more information about testing, see UKHSA Clinical advice on the diagnosis of Oropouche virus disease.

Due to the recent finding of OROV in semen, specialist advice should be sought; more information on factors to consider is available here.

As there is a risk of vertical transmission, possible cases in pregnant women should be reported to the UK Teratology Information Service for surveillance.

Outbreaks of OROV will continue to be monitored, together with any changing risks to travellers to affected regions. It is important to check for updates and further news items on this evolving situation.