Does the rise in respiratory illnesses in Chinese children mean a new pandemic?

A rise in respiratory illnesses among children in some parts of China is unlikely to herald a new global pandemic involving a new virus, scientists say.

The World Health Organization (WHO) has asked China to provide details on a rise in respiratory illnesses and pneumonia among young people amid reports that hospitals in cities such as Beijing and Liaoning are “overwhelmed with sick children”.

Experts warn it is too early to say for sure, saying a rise in pneumonia and other cases is much more likely due to the spread of existing respiratory viruses as China emerges from a long lockdown.

A similar picture was observed in the UK with influenza and other viruses after quarantine restrictions were lifted, scientists note.

WHO said it had requested additional epidemiological and clinical information, as well as laboratory results from reported outbreaks in children.

The main symptoms in children are high fever, which in some cases leads to the formation of pulmonary nodules in the lungs – an abnormal growth that is usually benign.

Reports emerged so quickly after Covid developed in China and spread around the world that fears inevitably arose that the outbreak could represent the next global pandemic.

While the reports are alarming, scientists said they do not indicate the emergence of a dangerous new virus.

Instead, they believe that the rise in respiratory infections is caused by existing viruses and their combinations.

“The current wave in China is likely caused by various respiratory pathogens such as RSV or influenza. However, it is likely that a significant proportion of cases are caused by the bacterium Mycoplasma pneumoniae, which is usually completely harmless,” said Professor Francois Balloux, director of the UCL Institute of Genetics in London.

RSV, or respiratory syncytial virus, is quite common in the UK and usually causes mild, cold-like symptoms, although it can be more severe in older people and young children.

Mycoplasma pneumoniae, on the other hand, is a mild form of pneumonia, also called atypical pneumonia because its symptoms are different from those of pneumonia caused by other common bacteria.

Professor Ballou said: “China is now likely to see a large wave of respiratory infections in children, as this is the first winter after a long lockdown, which must have sharply reduced the circulation of respiratory insects and therefore immunity to endemic insects.”

“Other countries, including the UK, saw large waves of respiratory infections and hospital admissions in children in the first winter after pandemic restrictions were eased.

“Given that China has been under a much longer and stricter lockdown than any other country in the world, it was expected that the waves of ‘lockdown release’ in China could be significant. In the absence of new data, there is no reason to suspect the emergence of a new pathogen.”

Professor Paul Hunter from the University of East Anglia also played down the risk that we are on the brink of another pandemic.

“In general, this does not look like an epidemic caused by a new virus to me. If this were the case, I would expect many more infections among adults. The few cases of infection reported in adults indicate immunity due to previous exposure.

“One explanation for the current problem is that restrictions have made the population immune to what causes current diseases, as we saw with flu and rotavirus in the UK last year.”

“Therefore, there is currently insufficient information to make a definitive assessment of the wider risk of this reported epidemic. “I believe this would not lead to a public health emergency of international concern, but I would not completely rule out the possibility until we have a definitive diagnosis.”

Dr Zaniya Stamataki, from the University of Birmingham, added: “There is currently no evidence that the rise in cases of childhood pneumonia in China could be caused by the new virus.” It is likely that individual respiratory infections or co-infections occur against the background of already circulating harmless viruses that can cause more serious diseases.”

“Recent work from several groups published earlier this year showed that existing, harmless circulating viruses may contribute to the development of co-infections that can cause tissue damage, such as the unexplained acute hepatitis in children reported by many countries in 2022.”