Graphics: What we know about the recent surge in respiratory illnesses

The current acute respiratory diseases reported in China are all caused by known pathogens, and no new infectious diseases caused by new viruses or bacteria have been identified, a health official said at the latest press conference of the National Health Commission (NHC), citing monitoring results. 

Monitoring data shows that the recent respiratory infectious diseases are mainly influenza, along with others caused by rhinovirus (RhV), mycoplasma pneumoniae (M. Pneumoniae), respiratory syncytial virus, adenovirus, and the like. 

The Chinese Center for Disease Control and Prevention (China CDC) released a health advisory recommending influenza vaccination in response to a winter surge in respiratory diseases on Tuesday. 

The advisory underscores that influenza vaccination is a cost-effective and efficient approach to preemptively tackle influenza viruses and mitigate the risk of severe infections and fatalities related to influenza. 

Influenza cases have shot up in parts of the temperate Northern Hemisphere, including parts of Asia, North America, Central America and the Caribbean. Among the cases recorded by World Health Organization (WHO)'s Global Influenza Surveillance and Response System, influenza A virus dominates. 

The WHO experts attributed the rise to a phenomenon known as "immunity gap," which has been observed across the globe after countries eased COVID-19 restrictions. An immunity gap was caused by a dramatic reduction in the circulation of viruses and bacteria due to strict COVID-19 precautions, which reduced people's immunological defenses against cold-causing viruses, especially those of children and the elderly.

Read more: China reports no new infectious diseases caused by new viruses or bacteria