Scientists expected a surge in respiratory disease, but what is happening in China is unusual.
China is grappling with a surge in respiratory illnesses, including pneumonia, in children. The World Health Organization (WHO) said last week that common winter infections — rather than any new pathogens — are behind the spike in hospitalizations. A surge of infections was expected in the country this winter, China’s first without COVID-19 restrictions since the pandemic began in 2020. What is unusual, say epidemiologists, is the high prevalence of pneumonia in China. When COVID-19 restrictions were eased in other countries, influenza and respiratory syncytial virus (RSV) drove most spikes in illness.
The WHO requested information, including laboratory results and data on recent trends in the spread of respiratory illnesses, from China’s health authorities last week. This followed reports from the media and the Program for Monitoring Emerging Diseases — a publicly available system run by the International Society for Infectious Diseases — about clusters of “undiagnosed pneumonia”.
In a 23 November statement, the WHO said that China’s health authorities have attributed the rise in hospitalizations since October to known pathogens, such as adenoviruses, influenza virus and RSV, which tends to cause only mild, cold-like symptoms. However, an increase in children being admitted to hospital since May, particularly in northern cities such as Beijing, is mainly due to Mycoplasma pneumoniae, a bacterium that infects the lungs. It is a common cause of ‘walking pneumonia’, a form of the disease that is usually relatively mild and doesn’t require bed rest or hospitalization, but that is hitting children hard this year.
Benjamin Cowling, an epidemiologist at the University of Hong Kong, is not surprised by the wave of illness. “This is a typical ‘winter surge’ in acute respiratory infections,” he says. “It is happening slightly earlier this year, perhaps because of increased population susceptibility to respiratory infections resulting from three years of COVID measures.”
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