Since mid-October 2023, the World Health Organization (WHO) has been monitoring data from Chinese surveillance systems that have been showing an increase in respiratory illness in children in northern China.
Chinese authorities attributed this increase to lifting of COVID-19 restrictions and the arrival of the cold season, and due to circulating known pathogens such as influenza, Mycoplasma pneumoniae, respiratory syncytial virus (RSV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Mycoplasma pneumonia and RSV are known to affect children more than adults.
Pneumonia is a form of acute respiratory infection that is most commonly caused by viruses or bacteria. It can cause mild to life-threatening illness in people of all ages; however, it is the single largest infectious cause of death in children worldwide.
Pneumonia killed more than 808 000 children under the age of 5 in 2017, accounting for 15% of all deaths of children under 5 years. People at-risk for pneumonia also include adults over the age of 65 and people with preexisting health problems.
When an individual has pneumonia, the alveoli are filled with pus and fluid, which makes breathing painful and limits oxygen intake. These infections are generally spread by direct contact with infected people. Vaccines can help prevent pneumonia.
Influenza (Flu) is a common cause of pneumonia, especially among younger children, the elderly, pregnant women, or those with certain chronic health conditions or who live in a nursing home.
Influenza is a highly contagious viral infection that is one of the most severe illnesses of the winter season. Influenza is spread easily from person to person, usually when an infected person coughs or sneezes.
Pneumonia is a serious infection or inflammation of the lungs. The air sacs fill with pus and other liquid, blocking oxygen from reaching the bloodstream. If there is too little oxygen in the blood, the body's cells cannot work properly, which can lead to death.
As flu strains change each year, it is necessary to get a flu vaccination each season to make sure you are protected against the most current strains. Pneumonia vaccinations are usually only necessary once, although a booster vaccination may be recommended for some individuals.
In recent days, there has been a surge in cases of infection by the bacterium mycoplasma pneumoniae Mycoplasma pneumonia reported in multiple hospitals across China, with children being the most affected. This year, the infection has occurred earlier than usual and has shown a trend toward affecting younger children, leading pediatricians to warn that this year could see a widespread outbreak of Mycoplasma pneumonia.
The Mycoplasma pneumoniae bacterium is one of the most recognized of all human pathogens, and there are different known species. These bacteria can cause many symptoms, including dry cough, fever, and mild shortness of breath on exertion. Mycoplasma pneumonia can spread easily among children.
Most people with respiratory infections caused by Mycoplasma pneumoniae don’t develop pneumonia. For this reason, Mycoplasma pneumonia is known as atypical pneumonia and is sometimes called walking pneumonia.
Mycoplasma pneumonia spreads quickly through contact with respiratory fluids in crowded areas, like schools, college campuses, and nursing homes. When someone coughs or sneezes, moisture containing the bacteria is released into the air, and others around them can easily breathe the bacteria in.
About 7 to 20 percent of cases of community-acquired (outside of a hospital) pneumonia happen as a result of infection by atypical bacterial microorganisms. Of these, Mycoplasma pneumoniae causes the most infections, though only about 10% of people infected will actually develop pneumonia.
Mycoplasma pneumonia symptoms are different from those of typical pneumonia caused by common bacteria, like Streptococcus and Haemophilus. Patients usually do not have severe shortness of breath, high fever, and a productive cough with Mycoplasma pneumonia. Instead, they have a low-grade fever, dry cough, mild shortness of breath, and fatigue.
Mycoplasma pneumonia may mimic an upper respiratory infection or common cold rather than a lower respiratory infection or pneumonia. A dry cough is the most common sign of infection.
In some cases, Mycoplasma pneumonia infection can become dangerous. If you have asthma, Mycoplasma pneumonia can make your symptoms worse. Mycoplasma pneumonia can also develop into a more severe case of pneumonia. In rare cases, untreated Mycoplasma pneumonia can be fatal.
Respiratory Syncytial Virus
Respiratory syncytial virus (RSV) causes mild illness in most children and adults. However, pneumonia can be serious, requiring treatment and sometimes hospitalization. Rarely, for people at high risk, pneumonia can be fatal.
For some infants, older adults, and people with certain health conditions, an RSV infection can become severe and lead to other health conditions, like bronchiolitis and pneumonia.
RSV typically stays confined to the upper airways. In certain situations, though, it can move into the lungs. While rare, this is when RSV-related pneumonia may develop. RSV is the leading cause of pneumonia in children under age 1.
Symptoms of RSV may be as mild as a runny nose and sore throat. When pneumonia develops, you may notice symptoms that happen slowly or suddenly. Symptoms may include cough with yellow, green, or bloody sputum, fever, chills, shallow or rapid breathing patterns, rapid pulse rate, chest pain with deep breaths or coughing, fatigue, and low appetite.
Don't Press Pandemic Panic Button
Scientists have cautioned against concerns of a potential new pandemic following the World Health Organization's request for more information from China regarding an increase in respiratory illnesses and pneumonia clusters among children.
While some worry that this surge might signal the emergence of another dangerous pathogen capable of triggering a pandemic, scientists believe, based on current information, it's more likely an increase in common respiratory infections like the flu. Similar rises in respiratory infections were observed globally after COVID-19 lockdowns were lifted, potentially including a resurgence of COVID itself.
Based on the available information, WHO recommends that people in China follow measures to reduce the risk of respiratory illness, which include recommended vaccines against influenza, COVID-19 and other respiratory pathogens as appropriate; keeping distance from people who are ill; staying home when ill; getting tested and medical care as needed; wearing masks as appropriate; ensuring good ventilation; and practicing regular handwashing.
WHO does not recommend any specific measures for travellers to China. In general, persons should avoid travel while experiencing symptoms suggestive of respiratory illness, if possible; in case of symptoms during or after travel, travellers are encouraged to seek medical attention and share travel history with their health care provider.
WHO advises against the application of any travel or trade restrictions based on the current information available on this event.