The Rio de Janeiro State Health Department (SES-RJ) has confirmed the fourth death from Oropouche fever in the state. The most recent victim was a 38-year-old woman from Nilópolis, in Baixada Fluminense, who became ill in early May after hiking in a city park. The infection was confirmed by tests conducted by the Noel Nutels Central Public Health Laboratory (Lacen-RJ) and Fiocruz. Oropouche fever is transmitted by the Maruim — a small biting mosquito commonly found in forested areas and near waterfalls.
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Other Deaths
Three other deaths caused by the disease have already been reported in the state of Rio de Janeiro. The first victim was a 64-year-old man from Cachoeiras de Macacu. The second and third were a 23-year-old woman from Paraty and a 34-year-old woman from Macaé. According to SES-RJ, these cases occurred in different regions and are considered isolated, with no new reports of hospitalizations or fatalities since then.
Cases in 2025
As of 4 June, according to the Monitora RJ dashboard, the state had recorded 1,836 confirmed cases of Oropouche fever. The cities with the highest number of cases are Cachoeiras de Macacu (672), Macaé (517), Angra dos Reis (392), and Guapimirim (172).
How Oropouche Fever is Transmitted
Oropouche fever is primarily transmitted by the Maruim (Culicoides paraensis), a tiny insect commonly found in forested areas, near waterfalls, and in banana plantations.
Symptoms
The symptoms of Oropouche fever are similar to those of dengue and include fever, body aches, and nausea. The incubation period ranges from four to eight days.
How to Prevent It
Prevention measures include wearing clothing that covers most of the body and applying body oils to exposed skin areas. Environmental care is also crucial: cleaning land and potential animal breeding sites, removing fallen leaves and fruit, and installing fine mesh screens on doors and windows are all recommended actions.
Analysis:
The confirmation of a fourth death from Oropouche fever in Rio de Janeiro is a growing public health concern that demands urgent attention from state and municipal authorities. With nearly 1,840 confirmed cases in 2025 alone, the geographic spread of infections—from coastal cities like Paraty and Angra dos Reis to inland cities such as Cachoeiras de Macacu and Guapimirim—indicates a pattern of environmental vulnerability in both forested and peri-urban areas.
The maruim (Culicoides paraensis), the vector responsible for the transmission of the virus, thrives in areas with dense vegetation, standing water, and poor land management. This environmental context, combined with increased human movement through ecotourism, urban sprawl, and inadequate prevention infrastructure, facilitates the silent expansion of the disease.
Sources: O Globo.
