Amazonian Oropouche virus in Europe. First cases of infection

Cases of Oropouche virus infection were reported in June and July in Spain (12), Italy (5) and Germany (2). Eighteen of the infected people had previously visited Cuba and one had previously visited Brazil.

Oropouche fever is a zoonotic disease caused by the Oropouche virus (OROV). To date, outbreaks of OROV have been reported in several countries in South America, Central America, and the Caribbean; they have occurred in Brazil, Bolivia, Colombia, Peru, and most recently in Cuba. Since January, more than eight thousand cases have been reported in these areas. The disease is transmitted to humans mainly through the bites of infected midges (Culicoides paraensis); however, Oropouche virus can also be spread by some species of mosquitoes.

The midge, which is the main vector (transmitter) of the virus, is widespread in the Americas (from the northern states of the USA to Argentina), but does not occur in Europe. It is not yet known whether European midges or mosquitoes can transmit OROV, in any case the risk of infection in European conditions is considered low – informs the ECDC. However, for EU citizens traveling to epidemic areas in South and Central America or residing there, the risk is currently assessed as moderate.

Symptoms of Oropouche virus disease include fever with headache, nausea, vomiting, muscle and joint pain, and sometimes more severe symptoms. The prognosis for recovery is good, and fatal cases are rare. There are no vaccines to prevent the disease or specific medications; treatment is symptomatic. No case of direct human-to-human infection has been reported to date. However, the Brazilian Ministry of Health recently reported six possible cases of mother-to-child transmission of OROV during pregnancy. Recent data suggest that OROV infection during pregnancy can lead to serious consequences, including miscarriage, and developmental problems and deformities in the fetus. This has not yet been definitively confirmed; research is ongoing. However, given the potentially harmful impact of congenital OROV infection and the fact that areas affected by OROV are also classified as regions with current or previous transmission of Zika virus, pregnant women are advised to follow travel recommendations related to both OROV and Zika virus, due to the similar associated risks. “The risk of OROV infection for citizens travelling to or residing in epidemic areas in South America, Central America and the Caribbean is currently assessed as moderate,” the ECDC said in a statement. However, the risk is increased for people visiting severely affected areas, particularly in the northern states of Brazil, the Amazon region, and/or not taking appropriate personal protective measures. Increased awareness among healthcare workers about travellers returning from areas with active OROV transmission, combined with adequate laboratory diagnostic capabilities, are essential for the early detection of travel-related cases. As symptoms of OROV disease can be similar to those of other arboviral infections such as dengue, chikungunya or Zika, laboratory testing for OROV should be performed when other tests for diseases with a common etiology are negative.

Travel health clinics should advise travelers traveling to outbreak areas about the risks of the disease and protective measures that can reduce the likelihood of infection. Personal protective measures to reduce the risk of bites in outbreak areas include using repellents according to the instructions on the product label, wearing long-sleeved shirts and long pants, and using insecticide-treated mosquito nets. These measures are essential to provide protection against bites in rooms that are not adequately screened (with fine-mesh screens on doors and windows) or air-conditioned, and during outdoor activities.