How to take care of respiratory diseases? 6:13

(CNN) -- Hospitals in northern China and Beijing have reported an increase in the number of children with respiratory illnesses, including pneumonia. Last week, the World Health Organization asked China to provide more information on the issue.

Based on what is known so far, how worrying are these cases? Why might there be an increase in respiratory illnesses? Should people traveling to China reconsider their plans? What additional precautions should governments, health systems, and individuals take?

To help us understand the situation, I spoke with CNN medical wellness expert Dr. Leana Wen. Dr. Wen is an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health. She previously served as Baltimore's Health Commissioner.

How worrisome is the reported increase in respiratory illnesses in China?

Dr. Leana Wen: So far, based on what we know from the WHO, I don't think the rise in respiratory diseases should cause global concern. What would be most worrying for the international medical community is whether a new pathogen is emerging, as happened with covid-19 in the winter of 2019. This does not seem to be the case at the moment.

After the WHO requested additional information from Chinese health authorities, it received data indicating that the increase in outpatient and hospital visits can be attributed to an increase in known, already existing pathogens. Specifically, there has been an increase in pneumonia due to Mycoplasma pneumoniae since May, and influenza, adenoviruses and respiratory syncytial virus (RSV) since October. The increases "are not unexpected, given the lifting of Covid-19 restrictions, as happened in a similar way in other countries," according to the WHO.


  • What's happening in China with pneumonia in children and why were hospitals overwhelmed?

Importantly, no new pathogens have been detected. Nor has there been any unusual clinical presentation in which children appear much sicker than normal.

Why would China be seeing such an increase now?

Wen: It is certainly crucial for the WHO and other members of the international medical community to independently verify this data, especially given the delay of the Chinese authorities in alerting the global community about covid-19. However, the situation in China actually mirrors what happened in the United States and many other countries last year.

Last winter in 2022, children's hospitals in the United States were flooded with children sick with COVID-19, flu, RSV and other common viruses. Much of this illness was attributed to the end of covid-19 mitigation measures.

During the peak of the pandemic, respiratory illnesses declined dramatically. Notably, children who would otherwise have been exposed to several infections a year did not get sick. When mitigation measures were lifted, communicable diseases swept through schools and daycare centers, leading to an increase in infections among children and therefore also those who required hospitalization.

China lifted its mitigation measures later than the United States and most other countries. It makes sense that, in the first full winter since the "zero-covid" policy ended, they would experience a surge in respiratory illnesses like much of the world experienced.

Chinese health authorities attribute the increase in pediatric pneumonia cases to Mycoplasma pneumoniae. What is that?

Wen: Pneumonia is a lung infection that can be caused by bacteria, viruses, and fungi. Mycoplasma pneumoniae is a common type of bacterial pneumonia. Some estimate that about 1% of the U.S. population is infected with Mycoplasma each year. Only 5% to 10% of people infected with Mycoplasma will develop pneumonia.

Pneumonia due to Mycoplasma is called "atypical" pneumonia. The onset of the disease is usually gradual, with patients experiencing non-specific symptoms such as low-grade fever, tiredness, and headache. Some people report a persistent cough or chest pain due to coughing. Sore throat, runny nose, and earache are also possible, and in rare cases, individuals may develop a rash, joint pain, and gastrointestinal symptoms.

According to the U.S. Centers for Disease Control and Prevention, Mycoplasma pneumoniae infections are most common in young adults and school-age children. People who live and work in crowded settings (such as schools) are at higher risk.

Most patients with this type of pneumonia do not need to be hospitalized and will improve with outpatient treatment with antibiotics. Those most vulnerable to serious illness are the very young, the elderly, immunocompromised people, and people with serious underlying medical conditions.

Could cases of pneumonia also be caused by other organisms?

Wen: Yes. Strep bacteria is another common cause of pneumonia. RSV and COVID-19 are among the types of viruses that can also cause pneumonia. Many health care facilities try to diagnose the source of the pneumonia and determine whether it is bacterial or viral. However, diagnostic capabilities in some areas may be more limited. In addition, a single person can have multiple infections at the same time and it is not always easy to attribute the manifestation of pneumonia to a single organism.

Should people avoid traveling to China at this time?

Wen: The WHO has explicitly said that it advises against "the application of any travel or trade restrictions based on the current available information on this event." It also does not recommend any specific preventive measures for travelers to China, although it does advise people in China to take steps to reduce the spread of respiratory illnesses. That includes staying home when you're sick, ensuring good ventilation, washing your hands regularly, and "wearing masks as appropriate."

I think this is all reasonable and I would also add that people vulnerable to severe illness from respiratory illnesses should take extra precautions, including wearing an N95 mask or equivalent in crowded indoor settings.

What additional precautions should governments and health systems, especially those in the rest of China and neighboring countries, take?

Wen: I agree with the WHO that limiting travel or trade would be unreasonable at this time, although of course the WHO should continue to press China to release up-to-date and accurate data.

In the meantime, governments and hospitals can bolster their own infrastructure. They should be on the lookout for an increase in flu-like illnesses and pneumonia cases and test promptly.

They must also ensure that they have the capacity to treat patients who need hospital care. It is quite possible that other areas, especially those with previously strict virus mitigation measures, will experience an increase in respiratory illnesses this winter. Health systems need to prepare for a potential influx of patients, as they did during the peak of covid-19.

Respiratory diseases