The Pan American Health Organization (PAHO) has issued an urgent epidemiological alert, calling on countries to enhance their surveillance and laboratory diagnosis of the Oropouche virus (OROV). This alert follows a significant increase in cases and the disease's spread into new regions, as well as the first recorded deaths and potential cases of vertical transmission.

As of the end of July 2024, there have been 8,078 confirmed cases of Oropouche fever across five countries: Bolivia (356 cases), Brazil (7,284 cases, including two deaths), Colombia (74 cases), Cuba (74 cases), and Peru (290 cases). The increase in cases, particularly in Brazil, has prompted concerns about the disease’s expanding geographic range and its potential for more severe manifestations.

Oropouche fever, traditionally transmitted by insect bites in the Amazon region, has now spread beyond its usual confines due to factors such as climate change, deforestation, and unplanned urbanization. This spread includes areas previously unaffected by the disease, such as Bolivia and Cuba.

Symptoms of Oropouche fever include sudden fever, severe headache, joint and muscle pain, rash, photophobia (sensitivity to light), diplopia (double vision), nausea, vomiting, and diarrhea. These symptoms typically last for five to seven days, with most patients recovering without lasting effects. However, some may experience prolonged recovery, and rare severe cases can involve aseptic meningitis.

PAHO has ramped up diagnostic capacity in 26 countries but notes that the disease's similarity to other arboviral infections and inconsistent surveillance may lead to underreporting. The organization recommends enhancing epidemiological surveillance, particularly for severe and fatal cases, and addressing potential vertical transmission from pregnant women to their fetuses.

Countries are urged to expand prevention efforts, including the use of repellents, protective clothing, and mosquito nets, and to implement stronger vector control measures. There are currently no vaccines or specific antiviral treatments for Oropouche fever; management remains symptomatic, focusing on pain relief and rehydration.

PAHO continues to monitor the situation and provide technical support to aid regional responses to the Oropouche virus outbreak.