Key Points

• In 2025, 188 cases of smallpox B (mpox) were reported, 4 of which were not biologically confirmed. The reported cases involved 181 men (96%) and 7 women. With the exception of one case in a child (<15 years old), all cases were adults with a median age of 34 years. Of the 44 men who reported contact with a case, 39 (89%) involved a sexual partner.
• The most affected population remains men who have sex with men (MSM).
• Just under two-thirds of the cases resided in Île-de-France (116/188, 62%). No cases residing in the French overseas departments and regions (DROM) were reported. In terms of risk exposures, 26% of documented cases (49/185) reported contact with a case within 3 weeks prior to their symptoms; and 18% (31/172) had traveled abroad within 3 weeks prior to their symptoms (Europe and sub-Saharan Africa).
• Among the 185 cases for which information was available, 13 (7%) were hospitalized, primarily for the management of severe pain (n=10 cases) or generalized rashes (n=7 cases).
• Regarding vaccination status when known, 59% (96/162) had not received any vaccine doses since May 2022. Among the 66 vaccinated cases, 18 had received a single dose (including 4 with a history of vaccination prior to 1984), 31 had received two doses (including 4 with a history of vaccination prior to 1984 as well), and 14 had received three doses. The number of doses received since 2022 was unknown for 3 cases.
• Of the 166 cases for which the clade was identified by the CNR for Orthopoxviruses, 162 belonged to clade IIb.
• Four cases of clade Ib were also identified: three men and one woman, aged 15 to 44; three cases were imported from Central or East Africa (an epidemic zone in 2025). Two cases were hospitalized, and the three cases for whom vaccination status was known were unvaccinated.