Oropouche fever (OF) is an arboviral disease caused by the Orthobunyavirus oropoucheense, described in Brazil in 1960, in the North region. Since then, the virus has been responsible for outbreaks, mainly in the Amazon, and is considered to have high dissemination potential. In 2024, however, the Ceará Health Secretariat confirmed 40 cases of OF, an unusual event, since the disease is not endemic in the state. Therefore, this study aimed to analyze the epidemiological distribution of OF in Brazil and in Ceará between 2024 and 2025, with emphasis on variables such as incidence, sex, and age group. This is an ecological and descriptive study comparing data from Brazil and the state of Ceará between epidemiological week (EW) 1 of 2024 and EW 25 of 2025. The following variables were considered: cases confirmed by RT-PCR, age group, and sex. Weekly data were obtained from the Ministry of Health Epidemiological Dashboard. In 2024, Brazil recorded 13,801 cases of OF. Up to EW 25 of 2025, there were 11,744 cases, exceeding the same period of 2024 (7,469). In Ceará, cases increased from 261 in 2024 to 662 in 2025, representing growth of 153.64%. In 2024, the highest incidence was among 30 to 39 years, both in Brazil (2,755) and in Ceará (53). In 2025, in Ceará, the most affected age group was 20 to 29 years (155 cases; 23.4%). In Brazil, this age group ranked third, behind 30–39 (2,233; 19%) and 40–49 (2,203; 18.8%). The lowest incidence was among those under 1 year of age: Brazil (39 in 2024 and 17 in 2025); Ceará (none in 2024 and two in 2025). Regarding sex, men were the majority: in Brazil, they represented 52.5% of cases in both years; in Ceará, 55.9% in 2024 and 52.4% in 2025. In 2025, Ceará had 656 autochthonous cases in eight municipalities in the regions of Baturité and Maracanaú, with emphasis on Baturité (440), in addition to 6 imported cases from cities such as Fortaleza, Sobral, and Rio de Janeiro. While Brazil showed a reduction in total OF cases between 2024 and 2025, the state of Ceará showed a significant increase. This reinforces the need to intensify epidemiological surveillance and adopt preventive measures aimed especially at young adult males. Comparative analysis between regions makes it possible to identify emerging patterns and guide containment and response strategies, especially in states previously non-endemic.
Salles et al. (Sun,) studied this question.