The World Health Organization said that China had shared data about a recent surge in respiratory illnesses in children, one day after the agency said it was seeking information about the possibility of undiagnosed pneumonia cases there.
The Chinese data indicated “no detection of any unusual or novel pathogens,” according to a W.H.O. statement on Thursday. The data, which included laboratory results from infected children, indicated that the rise in cases was a result of known viruses and bacteria, such as influenza and mycoplasma pneumoniae, a bacterium that causes usually mild illness.
Hospital admissions of children had increased since May, as had outpatient visits, but hospitals were able to handle the increase, China told the global health agency.
The W.H.O. requested information after Chinese news reports, and social media posts, indicated a notable surge in sick children in recent weeks. Parents reported long lines, sometimes of eight hours or more, at children’s hospitals. China’s National Health Commission acknowledged the reports of overcrowding.
Some of those reports also caught the attention this week of members of ProMED, a disease tracking site run by the International Society for Infectious Diseases that health officials monitor for early warnings of potential emerging diseases.
China’s transparency in reporting outbreaks has been the subject of intense global scrutiny, after it covered up early cases of both the SARS virus in 2003 and the virus that led to the coronavirus pandemic in 2020. The W.H.O. early this year rebuked Chinese officials for withholding data that the agency said could shed light on the coronavirus’s origins.
The W.H.O. issued its formal request for data one day after a ProMED member shared a news report from Taiwan about an uptick in sick children in Beijing and Liaoning, a northeastern Chinese province. Chinese officials had already publicly acknowledged an increase in respiratory diseases among children, but the W.H.O. said it was unclear at the time whether that increase was caused by known pathogens.
“A key purpose was to identify whether there have been ‘clusters of undiagnosed pneumonia’ in Beijing and Liaoning, as referred to in media reports,” the W.H.O. statement said.
The W.H.O. said the increased infections in China were earlier in the season than historically expected but “not unexpected,” given that this was the first winter since China had lifted the stringent coronavirus restrictions it imposed in 2020. Other countries experienced similar leaps in other illnesses after lifting their Covid controls.