Objective To detect global infectious disease events occurring outside China in April 2024 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 2024, 29 infectious diseases were detected to form events or outbreaks in 43 countries worldwide. In terms of importation risk to China, there are 27 medium-risk events; in terms of international travel risk, there are 22 high-risk events and 33 medium-risk events.

Conclusion It is recommended to pay moderate attention to the possible importation risk posed by Dengue fever in some countries in North and South America, Africa, Oceania, and Asia, mpox in Cambodia and America, cholera in Ethiopia, Yemen, and Mozambique, yellow fever in Brazil, chikungunya fever in Brazil and Argentina, whooping cough in Georgia, the Czech Republic, Russia, and Latvia, and measles in Russia. International travelers are advised to focus on dengue fever in Asian countries around China (Vietnam, Thailand, Cambodia, Indonesia, Nepal, Malaysia, Sri Lanka and Singapore), Mali, Argentina, Brazil, France and Peru, cholera outbreak in Yemen, Somalia, the Democratic Republic of the Congo and Mozambique, chikungunya fever outbreaks in Argentina and Brazil, Lassa fever in Nigeria, the scarlet fever in Armenia and yellow fever in Brazil, and to pay moderate attention to the possible risk of infection posed by the whooping cough outbreaks in Georgia, the Czech Republic, Russia, and Latvia, dengue fever outbreaks in Sudan, Chile, Bangladesh, Samoa, and French Polynesia, cholera outbreaks in Malawi, Ethiopia, Zimbabwe, Nigeria, Afghanistan, Brazil, and Comoros, polio outbreaks in Somalia, South Sudan, Yemen, the Democratic Republic of the Congo, Chad and Nigeria, mpox outbreaks in the United States, Cambodia and the Democratic Republic of Congo and Congo-Brazzaville, the measles outbreaks in Russia, Burkina Faso, Kyrgyzstan, Iraq, Bosnia and Herzegovina, and Afghanistan, and the psittacosis in Argentina.