China, experiencing its first winter without strict COVID-19 restrictions since the pandemic began, finds itself grappling with a surge in respiratory illnesses. The World Health Organization (WHO) has urged China to provide more information on the ongoing pneumonia outbreak, as health experts speculate on the causes behind this concerning trend.

The recent spike in cases has prompted the WHO to call for enhanced response measures and seek additional details from Chinese authorities. While the exact cause remains uncertain, some experts suggest that the surge could be a common and temporary aftereffect of lifting lockdown restrictions. However, unanswered questions surrounding the infections and their spread have led others to draw parallels with the early days of the COVID-19 pandemic.

What do we currently know about China’s pneumonia outbreak?

China’s National Health Commission reported an increase in respiratory diseases at a press conference on November 13. Additionally, the Program for Monitoring Emerging Diseases (ProMED) highlighted clusters of undiagnosed pneumonia in children in northern China. It is unclear whether these reports overlapped with the press conference information.

According to ProMED, infections have been proliferating in Beijing and Liaoning, a city in the country’s northeast, located around 800km (500 miles) apart. Concerned about this situation, the WHO has requested China to release more information on the outbreak, including epidemiologic and clinical data, as well as laboratory results from reported clusters among children.

Although official figures on the number of cases are not yet available, hospitals in Beijing have witnessed a surge in patients, particularly in the children’s wards. Absenteeism rates in schools are also alarmingly high, with entire classes being dismissed for at least a week if some students fall ill. As winter approaches, health officials worry that colder temperatures may exacerbate the spread of these infections.

Why is pneumonia spreading in China?

Chinese health authorities attribute the rise in cases to the lifting of COVID-19 restrictions. Experts concur, suggesting that this could be a result of the so-called “lockdown exit wave” observed in other countries like the United Kingdom. China may be experiencing an “immunity debt” due to its lengthy lockdown, which disrupted the circulation of respiratory bugs and possibly decreased immunity to endemic pathogens.

While it is crucial to consider the possibility of a novel pathogen, based on current information, there is no reason to suspect its emergence. Mycoplasma pneumoniae, a bacteria that commonly affects young children and is generally considered harmless, is likely responsible for most cases. The Chinese authorities have listed mycoplasma alongside respiratory syncytial virus (RSV) and SARS-CoV-2, the virus causing COVID-19, as circulating pathogens. The WHO has requested further information on the recent patterns of these microorganisms.

However, until more comprehensive data becomes available, it is also possible that the outbreak may be caused by an existing pathogen with modified characteristics and severity. Regardless of the exact cause, both scenarios would warrant global concern as pathogens inevitably cross national borders despite preventive measures.

What can we expect from the outbreak in China?

Chinese authorities emphasized the need to intensify disease surveillance and strengthen health systems during their press conference. The WHO and medical professionals in China advise people to reinforce practices from the COVID-19 pandemic era, such as regular handwashing, mask-wearing, and maintaining social distancing.

In Liaoning Province, people have been flocking to traditional Chinese medicine hospitals seeking treatment. At Dalian Children’s Hospital, patients have faced long queues, according to ProMED. Medical staff express concern about the increasing number of infections among individuals under 18. However, they are also worried about vulnerable populations such as the elderly and pregnant women. Experts believe that older individuals may have some immunity to certain pathogens, providing some reassurance. Nevertheless, more definitive information is needed to fully understand these illnesses.

Understanding pneumonia

Pneumonia refers to inflammation of air sacs in the lungs caused by bacterial, viral, or fungal infections. Although anyone can be affected by pneumonia, it is more common among young children and older adults. The infection can be life-threatening and is associated with higher mortality rates in Asia and sub-Saharan Africa, according to a 2022 WHO report.

Typical symptoms include chest pain, coughing, fever, and fatigue. Pneumonia can be treated with antibiotics when caused by bacteria. Recovery timelines vary but generally last from a week to a month or longer.

As China grapples with this pneumonia outbreak amid its changing COVID-19 landscape, global attention remains focused on understanding the causes and implementing effective response measures. The collaboration between China and international health organizations will be crucial in combating this surge in respiratory illnesses and safeguarding public health worldwide.