Europe calls for vigilance in face of local clade 1b mpox transmission
October 24, 2025
The European Centre for Disease Prevention and Control (ECDC) has confirmed community transmission of clade 1b mpox in Europe, with five locally acquired cases across Spain, Italy, Portugal, and the Netherlands. Although symptoms were mild, the detection of this more virulent strain outside endemic regions underscores the need for vigilance. The ECDC has urged targeted prevention, including vaccination for at-risk groups, rapid testing, clade identification, and strong community engagement, particularly among men who have sex with men (MSM). With similar cases also emerging in California, Europe’s early intervention and coordinated public health response will be crucial to containing further spread.
The European Centre for Disease Prevention and Control (ECDC) has issued an alert following confirmation of community transmission of clade 1b mpox in Europe. Five locally acquired infections were detected between mid-September and early October across Spain, Italy, Portugal, and the Netherlands, marking the first documented spread of this more virulent strain within the European Union. While all reported cases were mild, two of the three patients with available information were men who have sex with men (MSM), emphasizing the continued vulnerability of specific social and sexual networks that were most affected during the 2022 global mpox outbreak.
Previously, clade 1b infections in Europe were linked to travelers returning from mpox-endemic regions in Africa. The newly detected cases, however, indicate a shift to domestic transmission. The ECDC’s assessment highlights that although the immediate risk to the general population remains low, the risk for MSM is moderate, and the risk of severe disease is elevated for individuals with untreated HIV. Among 29 clade 1b cases previously reported to the ECDC, nearly one-fourth required hospitalization, although overall severity remains uncertain given limited data.
The ECDC is calling for comprehensive, evidence-based prevention strategies. Recommended actions include expanded vaccination coverage for at-risk populations, including post-exposure prophylaxis, accessible testing and clade differentiation, prompt diagnosis and isolation of confirmed cases, and contact tracing to disrupt transmission chains. Public health agencies are also encouraged to strengthen educational outreach in affected communities and healthcare systems to ensure early detection.
With recent non-travel-related clade 1 mpox cases reported in California, the emergence of localized transmission in Europe reinforces the need for sustained global surveillance. Continued coordination among EU member states, combined with timely vaccination and communication efforts, will be essential to prevent clade 1b mpox from establishing a broader foothold across Europe.