Human metapneumovirus (HMPV) cases have risen in China, leading to concern from some on social media over another COVID-like pandemic.
But the virus, while having similar symptoms and means of spreading as COVID-19, has been around for decades and is unlikely to pose the same global threat, according to experts.
Here is what you need to know.
What is HMPV?
HMPV, first identified in the Netherlands in 2001, is a common virus worldwide which belongs to the same family as RSV – short for respiratory syncytial virus.
For most people, it presents similarly to a common cold, but it can cause upper and lower respiratory disease in people of all ages, especially among young children, older adults, and people with weakened immune systems, according to the US Centers for Disease Control (CDC).
“Most people have had HMPV by the time they are five years old and catch it again throughout their lives,” says Dr Conall Watson, consultant epidemiologist at the UK Health Security Agency (UKHSA).
What are the symptoms?
The most common symptoms are a cold, cough, fever, nasal congestion, and shortness of breath.
If it progresses, it can lead to bronchitis or pneumonia and cause upper and lower respiratory infections.
“The reason that people may have to be hospitalised is if they’re running into trouble with maintaining oxygen levels and sometimes they need to go to intensive care or have mechanical ventilation, but that’s relatively unusual,” says Peter Openshaw, professor of experimental medicine at Imperial College London.
It can develop over three to six days after initial infection and, like other respiratory infections, its duration can vary.
How does it spread – and how can you prevent it?
It spreads either through human contact, or by touching objects or surfaces that have the viruses on them then touching the mouth, nose, or eyes.
Like RSV, it is a seasonal virus occurring mostly during the winter months.
Prevention guidance from the CDC lists the same methods as for other viruses like COVID, such as washing your hands regularly and thoroughly, and avoiding close contact with others if you/they are unwell.
There is no specific treatment for HMPV.
Dr Watson says: “As with all respiratory viruses, you can help reduce infections being passed on through regular handwashing and catching coughs and sneezes in tissues and throwing them away.
“If you have symptoms such as a high temperature, cough and feeling tired and achy, try to limit your contact with others, especially those who are vulnerable. There are many viruses in circulation at the moment, including flu – if you have symptoms of a respiratory illness and you need to go out, our advice continues to be that you should consider wearing a face mask.”
Why has there been concern?
In late December, China’s diseases control authority said it was stepping up its monitoring of emerging respiratory diseases, as they expected cases to rise over the winter and into spring.
Officials said the data for acute respiratory diseases showed an upward trend in overall infections in the week of 16 to 22 December, adding there had been a HMPV spike particularly among children under 14 in northern provinces.
This development, mixed with photos on social media hospitals in China full of people wearing masks, has led to fears of another pandemic.
But Professor Openshaw told Sky News he doesn’t think “there’s any likelihood of it causing a COVID-like pandemic”.
The professor, who specialises in viral infections of the lung, adds that while some viruses do evolve over time, “from what we know so far, there’s no reason to think that it’s changed its behaviour”.
“It’s a winter virus,” he adds. “It tends to cause quite severe outbreaks at this time of year. And also going through into February and March, it’s a bit later in terms of its epidemic peak than some other viruses.”
Read more:
At least 126 people killed after earthquake near holy city
Why is fluoride in drinking water controversial?
While HMPV isn’t likely to cause a pandemic, Professor Openshaw says the surge in viruses in China, as well as in many Western countries, is still “a very bad situation”.
“But it doesn’t seem to be any specific new threat. This is what we expect to see in the winter,” he explains.
“I think it’s so important that we redouble our efforts to find vaccines that are protective. And there are a lot of trials going on at the moment, which is good.”
What’s the situation in the UK?
The latest UKHSA data – from between 23 and 29 December 2024 – shows a slight increase in cases, but the UKHSA says that is in line with the trend commonly seen at this time of year.
“HMPV is a common respiratory infection in winter, and we typically see activity reaching a peak at this time of year,” says Dr Watson.
“Infections are usually mild, causing symptoms of a common cold. Our surveillance systems in GP surgeries and hospitals indicate that levels are in line with what we would expect to see.”