Prominent scientists emphasized the need for vigilance regarding concerns of a potential new pandemic on Thursday after the World Health Organization's (WHO) request for additional information from China regarding a potentially troubling increase in respiratory illnesses and clusters of pneumonia in children.
The U.N. health agency cited unspecified media reports and a global infectious disease monitoring service as reporting clusters of undiagnosed pneumonia in children in northern China.
In a statement late Wednesday, WHO said it was unclear whether those were linked to a rise in respiratory infections reported by Chinese authorities.
Outside scientists said the situation warranted close monitoring but were not convinced that the recent spike in respiratory illnesses in China signaled the start of a new global outbreak.
The emergence of new flu strains or other viruses capable of triggering pandemics typically starts with undiagnosed clusters of respiratory illness. Both SARS and COVID-19 were first reported as unusual types of pneumonia.
"We have to be careful," said Marion Koopmans, a Dutch virologist who advised the WHO on COVID-19. "We really need more information, particularly diagnostic information."
Concerns were first sparked internationally by an alert published on Tuesday by the monitoring service ProMED, part of the International Society for Infectious Diseases. It called for more information about "undiagnosed pneumonia – China (Beijing, Liaoning)."
The standard wording of the alert echoed the first-ever notice about what would become COVID-19, sent on Dec. 30 2019: "Undiagnosed pneumonia – China (Hubei)."
Scientists said the similarity of the two alerts had stirred as yet unfounded worries the surge may be caused by another emerging pathogen that could spark a pandemic.
They said based on the information so far, it was more likely to be a rise in other common respiratory infections like flu, as was seen in many parts of the world after COVID-19 lockdowns were lifted. It could also signal a resurgence of COVID-19 itself.
WHO said that northern China has reported a jump in influenza-like illnesses since mid-October compared to the previous three years.
The outbreaks have swamped some hospitals in northern China, including in Beijing, and health authorities have asked the public to take children with less severe symptoms to clinics and other facilities.
The average number of patients in the internal medicine department at Beijing Children's Hospital topped 7,000 per day, exceeding the hospital's capacity, state-owned China National Radio said in an online article earlier this week.
China's National Health Commission, in a written Q&A posted online by the official Xinhua News Agency, suggested Thursday that children with mild symptoms "first visit primary healthcare institutions or pediatrics departments of general hospitals" because large hospitals are crowded and have long waiting times.
The WHO always requests information from countries when undiagnosed or unknown diseases are reported, which happens fairly regularly. However, it does not always put out a press release about doing so, as it did on Wednesday.
Brian McCloskey, a public health expert who also advised WHO on the pandemic, said: "What we are seeing is WHO's International Health Regulations system in action," referring to the rules governing how countries work with WHO on potential outbreaks.
"I am not going to push the pandemic panic button on the basis of what we know so far, but I will be very keen to see the response to WHO from China and see the WHO’s assessment following that," he said.
Both the WHO and China have faced questions over transparency during the early days of COVID-19. WHO has also since criticized China for withholding data about infections and deaths when it lifted its "zero-COVID" measures, as well as about the origins of the pandemic.
China has 24 hours to respond to the WHO under the regulations.
However, some said it was unclear if the illnesses reported were actually undiagnosed. The story that sparked the ProMED alert came from FTV News in Taiwan on Tuesday. In China itself, there has been a lot of recent coverage of a rise in respiratory illnesses, including among children.
The authorities there have attributed it to the lifting of COVID-19 restrictions and the circulation of viruses like influenza as well as mycoplasma pneumoniae, a common bacterial infection that typically affects younger children.
"There is a plausible hypothesis that this could be what we have seen in other parts of the world when restrictions were lifted," said Koopmans.
Virologist Tom Peacock from Imperial College London, who has closely tracked the emergence of new coronavirus variants, said there were good tools available to "pretty rapidly" pick up emerging influenza or coronaviruses, so it seemed unlikely that this had happened under the radar.
"(I) suspect it may end up being something more mundane or a combination of things – say COVID, flu, RSV – but hopefully we'll know more soon," he said.
