Increase in febrile illness among children in mainland China, winter 2023 - 2024

In late 2023, mainland China reportedly saw a rise in respiratory illnesses, primarily among children. Officials from the Chinese Center for Disease Control attributed this increase to the circulation of known pathogens, including influenza viruses, respiratory syncytial virus, SARS-CoV-2, and mycoplasma pneumoniae, to which the population had only limited exposure while strict “zero Covid” measures were enforced in recent years. However, outside observers raised concerns that a novel infectious agent could be circulating, and the World Health Organisation took the unusual step of publicizing a request for further information from Beijing. While no novel pathogen has been identified at the time of writing, this apprehension among the international press, and among some public health experts, is an instructive reminder of how unresolved issues relating to the outbreak of SARS-CoV-2 in late 2019 continue to impact international public health. Such reactions suggest that the political control of epidemiological data in the early stages of the COVID-19 pandemic has had a lasting impact on international collaboration, institutional trust and global health security. Resolving these issues is essential if the world is to be prepared for future infectious disease outbreaks of potential international concern.