China is currently facing a mysterious outbreak of pneumonia, which has prompted the World Health Organization (WHO) to urge the country to reintroduce COVID-19-like measures, including the wearing of masks, social distancing, and staying home when unwell. This outbreak is particularly concerning as it comes at a time when China is experiencing its first winter without the strict COVID-19 restrictions that have been in place since the onset of the pandemic.
The pneumonia outbreak, which has seen a significant rise in cases since mid-October, is particularly concentrated in northern China, with infections proliferating in Beijing and the city of Liaoning. Hospitals in Beijing have reported a surge in patients, especially in children’s wards, with one major hospital seeing about 1,200 patients entering their emergency room daily. The situation has become so severe that schools in Beijing are reporting high levels of absenteeism and even dismissing entire classes for at least a week if some students are ill.
China’s National Health Commission has attributed the rise in cases to the lifting of COVID-19 restrictions. Health experts believe this could be similar to the “lockdown exit wave” witnessed in other countries. There is a theory that China may be experiencing an “immunity debt” after their lengthy lockdown, which reduced the circulation of respiratory bugs and hence decreased immunity to endemic bugs. The primary pathogens identified are mycoplasma, respiratory syncytial virus (RSV), and SARS-CoV-2, the virus that causes COVID-19.
While the presence of a novel pathogen is a possibility until more information is available, the outbreak could also be due to an existing but newly mutated pathogen with modified characteristics and severity. This situation has led to a need for increased disease surveillance and a strengthening of health systems in China. The WHO and medical staff in the country have advised people to reinforce practices from the COVID-19 pandemic era, such as rigorous handwashing, wearing masks, and social distancing, to mitigate the spread of the outbreak.