Mpox is a viral infection transmitted through direct contact with skin lesions, secretions, or contaminated objects. In March 2025, Brazil confirmed its first case of clade 1b, considered more lethal than the previous clade. This study aims to describe the current distribution of mpox cases in Brazil and the surveillance strategies adopted by the Ministry of Health. Cross-sectional, descriptive, quantitative study based on data from epidemiological reports by the Organização Pan-Americana da Saúde (OPAS), reports from the Centro de Operações de Emergência (COE), and technical notes from the Ministério da Saúde, covering 2024 to early 2025. Cases were distributed by sex, age group, geographic location, and time based on epidemiological weeks (EW), the standard temporal unit in public health surveillance. Between EW 1 of 2024 and EW 5 of 2025, 2,170 confirmed or probable mpox cases were reported in Brazil. An upward trend was observed starting in EW 30/2024. Most cases occurred in the Southeast region (72%), especially in São Paulo (51.4%) and Rio de Janeiro (16.2%). Men accounted for 94% of cases, with 44% in the 30–39 age group. In response to clade 1b circulation, the Ministério da Saúde issued Nota Técnica 67/2024, updated laboratory protocols, and distributed new diagnostic kits for early detection. The predominance of cases in young men and the regional concentration reinforce the need to expand epidemiological surveillance and health education actions. In addition, sexual transmission has been prevalent, which requires targeted prevention strategies. Finally, early detection and continuous data updates are essential to guide interventions and contain spread of the new clade.
Sampaio et al. (Sun,) studied this question.