Description of the Situation
Since mid-October 2023, the World Health Organization (WHO) has been closely monitoring data from Chinese surveillance systems, revealing an uptick in respiratory illnesses among children in northern China.
In a press conference on November 13, 2023, China’s National Health Commission reported a nationwide rise in respiratory diseases, predominantly affecting children. Chinese authorities attributed this increase to the relaxation of COVID-19 restrictions and the onset of the cold season, along with the circulation of known pathogens like influenza, Mycoplasma pneumoniae, respiratory syncytial virus (RSV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Mycoplasma pneumonia and RSV are known to impact children more than adults.
On November 22, 2023, WHO identified media and ProMED reports highlighting clusters of undiagnosed pneumonia in children’s hospitals in Beijing, Liaoning, and other locations in China. Through the International Health Regulations mechanism, WHO officially requested additional epidemiologic and clinical information, as well as laboratory results from the reported cases and data on recent trends in circulating respiratory pathogens. The goal was to determine whether there were “clusters of undiagnosed pneumonia” in Beijing and Liaoning, as reported in the media, and if these were isolated incidents or part of the overall increase in respiratory illnesses in the community. WHO also sought additional information through clinical networks.
On November 23, WHO conducted a teleconference with Chinese health authorities from the Chinese Center for Disease Control and Prevention and the Beijing Children’s Hospital. The Chinese authorities, facilitated by the National Health Commission and the National Administration of Disease Control and Prevention, provided the requested data, indicating an increase in outpatient consultations and hospital admissions of children due to Mycoplasma pneumoniae pneumonia since May and RSV, adenovirus, and influenza virus since October. Some of these increases occurred earlier in the season than historically observed but were anticipated due to the easing of COVID-19 restrictions, similar to experiences in other countries. Chinese health authorities reported no changes in disease presentation and no detection of unusual or novel pathogens or clinical presentations, emphasizing the general rise in respiratory illnesses due to multiple known pathogens. They further clarified that the surge in respiratory illnesses has not overwhelmed hospital capacities.
Chinese authorities informed that since mid-October, enhanced outpatient and inpatient surveillance for respiratory illnesses, covering a broad spectrum of viruses and bacteria, has been implemented. This includes, for the first time, surveillance for Mycoplasma pneumoniae. This additional surveillance complements existing respiratory surveillance mechanisms and may have contributed to the observed increase in the detection and reporting of respiratory illnesses in children.
Public Health Response
Starting from mid-October, Chinese authorities have not only bolstered disease surveillance in healthcare facilities and community settings but also emphasized the importance of strengthening the health system’s capacity to handle patients. China has established systems to gather information on trends related to influenza, influenza-like illness (ILI), respiratory syncytial virus (RSV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), pneumonia, and other severe acute respiratory infections (SARI). It actively reports influenza detections to platforms like the Global Influenza Surveillance and Response System (GISRS), led by WHO, which is utilized for international virological and epidemiological surveillance of human influenza.
WHO is actively monitoring the evolving situation and maintaining close communication with national authorities in China. Updates will be provided by WHO as deemed necessary.
WHO Risk Assessment
The current outbreak of respiratory illness presents symptoms common to various respiratory diseases. At present, Chinese surveillance and hospital systems indicate that the clinical manifestations are attributed to known circulating pathogens. Mycoplasma pneumoniae, a frequent respiratory pathogen and common cause of pediatric pneumonia, is easily treatable with antibiotics.
China maintains an influenza-like illness (ILI) and severe acute respiratory infections (SARI) sentinel surveillance system. Since mid-October, an enhanced surveillance system for respiratory illnesses, encompassing a wide range of respiratory viruses and bacteria, including Mycoplasma pneumoniae, has been implemented.
Detailed information to comprehensively assess the overall risk of the reported cases of respiratory illness in children is limited. However, with the onset of the winter season, an upswing in respiratory illnesses is anticipated, and the co-circulation of respiratory viruses may impose an increased burden on healthcare facilities.
Surveillance data reported to WHO’s FluNet and published by the National Influenza Centre in China indicate that ILI has surpassed usual levels for this time of year and is on the rise in the northern provinces. Influenza detections are predominantly A(H3N2) and B/Victoria lineage viruses.
WHO Advice
Based on the existing information, WHO suggests that individuals in China adhere to measures aimed at minimizing the risk of respiratory illness. These measures include receiving recommended vaccines against influenza, COVID-19, and other relevant respiratory pathogens; maintaining a safe distance from individuals displaying symptoms; staying at home when feeling unwell; undergoing testing and seeking medical care as necessary; wearing masks as appropriate; ensuring proper ventilation; and practicing regular handwashing.
For travelers to China, WHO does not prescribe any specific measures. Generally, individuals should avoid travel if experiencing symptoms indicative of respiratory illness, if feasible. In the event of symptoms during or after travel, travelers are encouraged to seek medical attention and provide their travel history to healthcare providers.
WHO discourages the implementation of travel or trade restrictions based on the current information available regarding this event.
Further Information
- ProMed article. Undiagnosed pneumonia – China: Promed Post – ProMED-mail (promedmail.org)
- WHO statement on reported clusters of respiratory illness in children in northern China: WHO statement on reported clusters of respiratory illness in children in northern China
- Data and commentary from Press Conference of National Health Commission, 13 Nov 2023 http://www.nhc.gov.cn/xcs/s3574/202311/0807e750e6cc4a81a22b6d881913cf5d.shtml
- Data on SARS-CoV-2 and influenza from China https://www.chinacdc.cn/jkzt/crb/zl/szkb_11803/jszl_13141/202311/t20231110_270578.html
Citable reference: World Health Organization (23 November 2023). Disease Outbreak News; Upsurge of respiratory illnesses among children in northern China. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2023-DON494