Risk assessment of global infectious disease events in April 2025

Objective To detect global infectious disease events occurring outside China in April 2025 and assess the importation risk to China and international travel risk.

Methods Utilizing open-source intelligence on the internet, this study conducts event-based surveillance of priority infectious diseases and adopts the risk matrix methodology to build an indicator system by integrating disease-, country- and event-specific indicators in terms of transmission likelihood and severity of consequences in order to assess the risk of the importation and the risk of international travel.

Results In April 2025, 16 concerned infectious diseases were detected to form events or outbreaks in 35 countries worldwide. In terms of importation risk to China, there are 4 high-risk events and 27 medium-risk events; in terms of international travel risk, there are 10 high-risk events and 32 medium-risk events.

Conclusion It is recommended to pay close attention to dengue fever in Asia, chikungunya fever in Reunion Island, zika virus disease（ZVD） in Burkina Faso, which may pose import risks. In terms of overseas travel risks, it is recommended that international travelers pay close attention to dengue fever in North America and Asia, mpox outbreaks in Uganda, Cholera in Kenya and Myanmar, chikungunya fever in Republic of Mauritius, ZVD in Burkina Faso. Compared to March 2025, general attention should be paid to dengue fever in Samoa, Colombia, Yemen and Laos, mpox in Philippines, yellow fever in Colombia and Ecuador, Cholera in Democratic Republic of the Congo and Yemen, poliomyelitis in Ethiopia, rift valley fever in Senegal in April 2025.