Brazil: Oropouche cases top 4,000 in 2025

In 2024, Brazil health authorities reported 13,781 confirmed cases of Oropouche fever across the country, up from 832 cases reported in all of 2023.

Through February 11 this year, the Ministry of Health reports 4310 confirmed cases, with the bulk of the cases in 4021 cases reported in Espirito Santo state in southeastern Brazil, with the Atlantic Ocean on its eastern border.

The surrounding states of Rio de Janeiro (217) and Minas Gerais (34) follow as states with the second and third most cases.

Regarding deaths associated with Oropouche in 2024, the Brazil International Health Regulations (IHR) National Focal Point (NFP) reported four deaths associated with Oropouche virus infection in the states of Bahia (n= 2 cases), Paraná (n= 1 case), and Espírito Santo (n= 1 case); and a few cases under investigation.

With regard to cases of vertical transmission and its consequences as of EW 52 of 2024, five cases of vertical transmission have been confirmed: four cases of fetal death in Pernambuco (n=3) and Ceará (n=1) and one case of congenital anomaly in Acre.

Additionally, on 12 August 2024, Brazil reported a case of Oropouche virus-associated encephalitis in a male resident of the state of Piauí.

Oropouche is a disease caused by Oropouche virus. It is spread primarily through the bites of infected biting midges (small flies) and mosquitoes. Oropouche virus has been found in semen. It is unknown if Oropouche can be spread through sex.

Symptoms of Oropouche include headache, fever, muscle aches, stiff joints, nausea, vomiting, chills, or sensitivity to light. Severe cases may result in neuroinvasive disease such as meningitis.

Symptoms typically start 3–10 days after being bitten and last 3–6 days. Most people recover without long-term effects. There is no specific treatment for Oropouche.

Venezuela epidemics: From measles to malaria with Dr. Alberto Paniz-Mondolfi