Objectives To detect global infectious disease events occurring outside China in September 2026 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 September 2026, 15 infectious diseases were detected to form events or outbreaks in 71 countries or regions worldwide. In terms of importation risk to China, there were 1 high-risk event, 37 medium-risk events; in terms of international travel risk, there were 5 high-risk events, 47 medium-risk events.

Conclusion  For importation risk, it is recommended to pay close attention to the chikungunya outbreak in Brazil, and pay general attention to dengue in Pakistan, Brazil, Ecuador, France, the Philippines, Colombia, Kenya, Malaysia, the United States, Bangladesh, Peru, Mexico, Sri Lanka, Italy, India, Vietnam and Taiwan, China; chikungunya in Argentina, Pakistan, Bolivia, France, French Guiana, Costa Rica, Honduras, Nicaragua, Macao SAR, China, Taiwan, China and Hong Kong SAR, China; cholera in Pakistan, the Democratic Republic of the Congo, Cameroon, Myanmar, Mozambique, Nigeria and Zambia; diphtheria in France; and Ebola virus disease in the Democratic Republic of the Congo. For international travel risk, it is recommended to pay close attention to dengue in Brazil, Malaysia and Peru, chikungunya in Brazil, and cholera in Nigeria, and pay general attention to dengue in Argentina, Panama, Cuba, Costa Rica, Honduras, the Marshall Islands, El Salvador and Vanuatu; cholera in Sudan, Yemen and Chad; diphtheria in Morocco, Nigeria and Senegal; Lassa fever in Liberia; and yellow fever in Ghana. The remaining 31 events of general attention are the same as those listed under importation risk.