Authorities attributed the increase to the lifting of COVID-19 restrictions and the circulation of known pathogens such as influenza, mycoplasma pneumoniae, a common bacterial infection that typically affects younger children, respiratory syncytial virus (RSV), and the virus that causes COVID-19.Both China and the WHO have faced questions about the transparency of reporting on the earliest COVID-19 cases that emerged in the central Chinese city of Wuhan in late 2019. On Wednesday, the WHO said groups including the Program for Monitoring Emerging Diseases (ProMED) reported clusters of undiagnosed pneumonia in children in north China. The WHO said it was not clear if these were associated with an overall increase in respiratory infections previously reported by Chinese authorities or separate events.
The WHO said it had asked for additional epidemiologic and clinical information as well as laboratory results from the reported outbreaks among children, through the International Health Regulations mechanism. Under the rules, China is supposed to respond to WHO within 24 hours.