A rise in respiratory illnesses in China, particularly among children, has made headlines over the past few weeks, with global health authorities trying to estimate the scale and severity of illness.

On November 13, 2023, China's National Health Commission reported an increase in the incidence of respiratory diseases in China, stressing the need for enhanced disease surveillance in healthcare and community settings, and strengthened health system capacity.

With some hospitals reporting large numbers of cases, and other nations making preparations should illnesses spread, Newsweek has summarized the story so far and what the relative risk within China and across the globe may be.

China hospital
Children and their parents wait at an outpatient area at a children hospital in Beijing on November 23, 2023. Cases of respiratory illnesses, particularly among children, have spiked since October.
JADE GAO/AFP via Getty Images

What Illnesses Have Been Reported and What Are the Symptoms?

Chinese state media Global Times reported earlier this week that the country's National Health Commission said the cases were mainly influenza, alongside mycoplasma pneumonia, rhinovirus infections, respiratory syncytial virus, adenovirus, and other illnesses.

Experts say China's stringent anti-COVID measures, which were dropped less than a year ago, left children's immune systems unprepared, resulting in the preponderance of younger patients. No major rise in deaths has been reported.

Scientists outside of China have attempted to assess the patterns of illness independently. Paul Hunter, a professor in medicine at the U.K.'s University of East Anglia, told the Science Media Centre on November 22 that the illness in children was a fever with no cough or other symptoms although, in some cases, pulmonary nodules had been seen on chest x-rays.

"Whilst we can't make a definitive diagnosis at this stage the presence of pulmonary nodules tend to suggest a bacterial rather than a viral cause," Hunter said.

"Pulmonary nodules in children are seen in pneumococcal pneumonia and cough may be absent. Influenza can catch patchy changes on chest X-ray, often due to secondary bacterial infections so [that] could also be in the frame.

"Whilst we can't make a definitive diagnosis at this stage the presence of pulmonary nodules tend to suggest a bacterial rather than a viral cause."

Hunter added that it did not sound like an epidemic due to a novel virus, adding that he would "expect to see many more infections in adults" in that case.

Nonetheless, some concerns have grown that older Chinese residents may come into contact with pathogens during family gatherings later in the year.

The pattern of China's outbreak suggests it began several months ago, Chinese health experts told various state media publications this week. They expect cases to peak in the next 2-3 weeks, but infections could last through next spring.

Health officials have urged the public to get vaccinated for relevant diseases.

How Many People Have Been Affected and Where?

While there have been localized reports from hospitals across China, the total number of patients across the country isn't clear.

Chinese state media has reported that in Taizhou in East China's Zhejiang province, as of Friday, November 24, the positive rate of influenza virus in outpatient cases in the city had increased to 50 percent.

The Tianjin Children's Hospital, located in a major port city near the capital Beijing, reported on November 18 a single-day record of 13,171 young patients across its outpatient and emergency departments, according to a local newspaper. The geographical spread of cases, spanning over 400 miles from Beijing to Liaoning, suggested a wider outbreak that began in northern China.

Last week, state-run CCTV news reported that in the capital of Beijing, hospitals had been operating at full capacity for over a month in response to this spike in infection. Beijing Children's Hospital revealed that its internal medicine department had seen more than 7,000 cases daily. Beijing Jingdu Children's Hospital highlighted a significant rise in mycoplasma pneumonia infections, placing immense pressure on medical resources, with 90 percent of the hospital's 300 beds occupied and long queues forming outside.

On November 21, Chinese media and ProMed, the alert system known for its role in bringing attention to the coronavirus outbreak in 2019, reported that there had been clusters of undiagnosed pneumonia among children in northern China, although it was unclear if this was related to the reported respiratory outbreaks.

ProMed first reported numerous children being admitted to hospitals with high fevers but without typical pneumonia symptoms.

In northern China, which appears to be experiencing the worst of the outbreak, respiratory infections have surged for five consecutive weeks, accounting for 6.2 percent of outpatient and emergency visits, at a rate 2.5 times the average of the past three years, Lo Yi-chun, the deputy director of the Taiwan Centers for Disease Control said on Sunday, citing World Health Organization (WHO) data.

Health authorities such as the WHO have repeatedly asked China for further epidemiological data.

Dr. Maria Van Kerkhove, acting director of the WHO's Department of Epidemic and Pandemic Preparedness and Prevention, said on Thursday: "We are following up with the situation in China and again, they have seen overall an increase in acute respiratory infections due to a number of different pathogens, including influenza, which is on the rise."

She continued, "Mycoplasma pneumonia was on the rise for the last couple of months and now seems to be a little bit on the decline. We are following up through our clinical networks and working clinicians in China to better understand resistance to antibiotics which is a problem across the world."

What’s the Relative Risk to Other Parts of the World?

The Taiwan Centers for Disease Control said on Saturday that the island's ports and airports were all put on "high alert." Notices were placed at these locations urging travelers arriving from mainland China, Hong Kong and Macau to seek medical attention if symptomatic, and disclose their travel history to healthcare providers.

Fang Chi-Tai, a professor at the Institute of Epidemiology and Preventive Medicine at National Taiwan University, told Newsweek on Monday that Taiwan had heightened disease surveillance and recommends preventive measures such as mask-wearing as well as maintaining personal hygiene upon arrival in China.

Taiwan's public health authority said individuals planning trips to China should consider receiving vaccines for COVID and influenza at the earliest opportunity.

Nearby nations such as India and Vietnam have said that while they are not seeing an uptick in cases, their health systems are preparing and have reached out to health authorities such as the WHO and the Centers for Disease Control and Prevention for advice.

However, the relative risk according to experts appears to be low. Speaking to healthcare publication STAT, the WHO's Van Kerkhove reiterated the view that the spike in cases was due to an immunity gap in China, following the lifting of COVID restrictions, and was something most other countries had already dealt with.

"This is not an indication of a novel pathogen. This is expected," Kerkhove said.

"This is what most countries dealt with a year or two ago.

"We asked about comparisons prior to the pandemic. And the waves that they're seeing now, the peak is not as high as what they saw in 2018-2019."

Speaking to CNN, Dr. Leana Wen, former Baltimore Health Commissioner and professor of health policy and management at the George Washington University Milken Institute School of Public Health, said the cases should not cause global concern.

"The spikes are "not unexpected given the lifting of COVID-19 restrictions, as similarly experienced in other countries," according to WHO, she said.

"Importantly, no new pathogen has been detected. There has also been no unusual clinical presentation with children appearing much sicker than normal."