This is the 51st situation report for the multi-country outbreak of mpox, which provides details on the global epidemiological situation for mpox with data as of 31 March 2025, including an update on the epidemiological situation for mpox in Africa, with data as of 20 April 2025, updates on imported cases of mpox due to clade I MPXV as of 25 April 2025, and the operational response updates as of 25 April 2025.
Highlights
• Cases of mpox due to clade Ib monkeypox virus (MPXV) continue to be reported primarily in Africa, where eleven countries have reported community transmission of this strain in the past six weeks.
• Wherever mpox outbreaks are not quickly contained and human-to-human transmission is not stopped, they continue to represent a potential risk of sustained transmission in the community.
• Currently, Uganda is reporting the highest number of confirmed mpox cases globally, with 200 to 300 new cases reported per week3 . To date, the country has detected only clade Ib MPXV.
• The Democratic Republic of the Congo continues to report the highest number of cumulative confirmed mpox cases in Africa in 2025, despite a decreasing number of confirmed cases reported in recent weeks likely due to a reduction in testing and confirmation capacity. Clades Ia and Ib MPXV continue to circulate in the country.
• Burundi continues to observe a declining trend of confirmed cases, with fewer than 50 new confirmed cases per week, down from over 200 confirmed cases per week at the peak of the outbreak.
• Sierra Leone has reported a rising number of confirmed mpox cases, with over 200 new confirmed cases reported during the most recent week, highlighting the increased transmission in the country. Details on the epidemiological characteristics are currently being gathered.
