Oropouche Fever

Causative agent

Oropouche fever is caused by the Oropouche virus. The Oropouche virus is present mostly in Central and South America and the Caribbean, but since December 2023 more cases were reported, including from areas in the Americas where it was not previously detected.

Clinical features

• Symptoms of Oropouche fever are similar to those of dengue fever.
• Patients may present with high fever, headache, muscle and joint pain, rash, and vomiting.
• The symptoms usually last for 3 to 6 days. Most patients recover completely within 7 days after the onset of symptoms.
• Approximately 60% of cases experience relapse of symptoms weeks after recovery.
• Currently, the understanding of complications from Oropouche fever is limited. Severe complications like meningitis may occasionally occur.
• Infection during pregnancy may lead to birth defects and fetal death.

Mode of transmission

The Oropouche virus is primarily transmitted to humans through the bites of infected midges, Culicoides paraensis. Some mosquitoes such as Culex quinquefasciatus can also be a vector.

Vertical (mother-to-child) transmission has been documented recently and is still under investigation.

Incubation period

3 to 10 days, usually 4 to 8 days

Management

There is no specific treatment for Oropouche fever. Supportive therapy is the mainstay of treatment on relieving symptoms.

Prevention

There is no vaccine available to prevent Oropouche fever. Vector control and personal protective measures are the key in reducing the spread of the virus.

Personal protective measures, such as wearing protective clothing and using insect repellents containing DEET, IR3535 or icaridin, are recommended to minimize the risk of infection.

For details about the use of insect repellents and the key points to be observed, please refer to 'Tips for using insect repellents'.