What you need to know about human metapneumovirus cases in China

A surge in cases of flu-like human metapneumovirus (HMPV) in China has raised fears of another coronavirus pandemic.

Images of hospitals crowded with masked patients have been widely circulated on social media, but health experts say HMPV is different from the coronavirus, noting that it has been around for years.

They say China and other countries simply experience seasonal increases in HMPV, usually in the winter.

HMPV was first discovered in the Netherlands in 2001 and is spread through direct contact between people or when someone touches a contaminated surface.

For most people, the virus causes a mild upper respiratory tract infection.

It is often indistinguishable from the flu.

Symptoms include cough, fever and nasal congestion in most people.

Young children, including those under two years old, are most vulnerable to the virus.

It also poses a greater risk to people with weakened immune systems, including the elderly and patients with advanced cancer, said Singaporean infectious disease expert Dr Koh Li Yang.

If infected, a “small but significant proportion” of immunocompromised people may develop more severe lung disease, including symptoms of wheezing, difficulty breathing and croup.

“Many people require hospitalization and only a small number are at risk of dying from the infection,” Dr Xu said.

Like many respiratory infections, HMPV is most active in late winter and spring.

This is because the virus survives better in the cold and spreads more easily from one person to another as people spend more time indoors with their windows closed.

In northern China, the current HMPV peak coincides with low temperatures expected to last until March.

Many other countries in the northern hemisphere – including the United States – are also experiencing rising rates of HMPV, said Jacqueline Stephens, an epidemiologist at Australia's Flinders University.

“While this is concerning, the increase in prevalence may be a normal seasonal increase that occurs during the winter,” she said.

The World Health Organization (WHO) is monitoring the incidence of influenza-like illness throughout the Northern Hemisphere and It said it had not received any reports of unusual epidemic patterns in China or elsewhere..

According to the report, Chinese authorities have confirmed that the health care system is not overwhelmed and there has been no emergency declaration or response so far.

The incidence of HMPV in the UK has increased steadily since October 2024.

The UK Health and Safety Authority (UKHSA) does not publish the number of cases recorded.

However its latest data The proportion of people testing positive for the disease showed a sharp rise in the third week of December and remained high the following week.

But HSA said this was entirely in line with normal seasonal trends and disease levels in GP surgeries and hospitals were in line with expectations.

Experts say concerns about the novel coronavirus pandemic are overblown, noting that such events are typically caused by new viruses, but not HMPV.

This disease is already present across the globe and has been for decades. Dr Xu said this meant people around the world had “some level of immunity due to previous exposure”.

Paul Hunter, professor of medicine at the University of East Anglia in the United Kingdom, said: “Almost every child will have been infected with HMPV at least once by their fifth birthday, and we would expect to be reinfected many times throughout their lives.”

“I don't think there's any indication at the moment that there's a more serious global problem.”

However, health officials recommend taking reasonable precautions to avoid becoming infected with HMPV and other respiratory illnesses:

• Wear a mask when going to crowded places
• If you are at higher risk for more severe illness, avoid crowds if possible
• wash hands often
• Safe disposal of paper towels

People may also want to consider getting vaccinated to protect against other respiratory illnesses like the flu.

In the UK, the vaccine is recommended for pregnant women and adults aged 75 to 79 Respiratory Syncytial Virus (RSV) Vaccine.

RSV is a common infection that causes coughs and colds but can sometimes be serious in babies and older adults.