Objectives To detect global infectious disease events occurring outside China in December 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 December 2025, 13 infectious diseases were detected to form events or outbreaks in 29 countries worldwide. In terms of importation risk to China, there are 13 medium-risk events; in terms of international travel risk, there are 6 high-risk events and 23 medium-risk events.

Conclusion It is recommended to pay moderate attention to the possible importation risk posed by dengue fever in Singapore, Bangladesh, Malaysia, Sri Lanka, Mexico, Cuba and Brazil, chikungunya fever in Brazil, Cuba and the United States, cholera in Pakistan, marburg hemorrhagic fever in Ethiopia, MERS in France. Regarding overseas travel risks, it is advised that travelers pay close attention to dengue fever in Brazil, Bangladesh, Mexico and Cuba; chikungunya fever in Cuba, marburg hemorrhagic fever in Ethiopia. Compared to November, in December, general attention should also be paid to the potential infection risks posed by dengue fever in Malaysia and Sri Lanka, chikungunya fever in the United States and Bolivia, cholera in Pakistan and Malawi, Lassa fever in Nigeria, diphtheria in Somalia and Mali, Rift Valley fever in Mauritania, yellow fever in Colombia, and polio in Ethiopia, Somalia, Sudan, Angola, Nigeria, Chad, and the Democratic Republic of the Congo.