Oropouche cases top 5,000 in Brazil through first 2 months of 2025

The Brazil Ministry of Health has reported 5,514 confirmed Oropouche cases through February 25.

More than eight out of 10 cases in the country are reported from Espirito Santo state (4,643). Rio de Janeiro state has reported 485 cases and Paraiba state with 287 cases.

One death is under investigation.

In all of 2024, Brazil saw 13,784 Oropouche cases and only 832 cases in 2023.

Oropouche virus disease (OROV) was first identified in 1955 in Trinidad and Tobago, OROV has caused cases and outbreaks in several South American countries, including Brazil, Colombia, Ecuador, French Guiana, Panama, Peru and Venezuela.

Outbreaks have been most frequent in the Amazon Basin region, where the most known vector, the midge (Culicoides paraensis), maintains a sylvatic cycle involving hosts such as sloths and non-human primates.

Symptoms of Oropouche fever include sudden fever, severe headache, extreme weakness (prostration), joint and muscle pain. In some cases, photophobia, dizziness, persistent nausea or vomiting, and low back pain may occur. Fever usually lasts up to five days. Although serious complications are rare, the disease can progress to aseptic meningitis, which usually manifests in the second week of illness, prolonging recovery by weeks. Up to 60% of cases are reported to have relapses of symptoms in the weeks following recovery.