Top British virus experts have called on Chinese authorities to disclose vital information about a worrying outbreak of the respiratory infection hMPV, which is reported to be overwhelming its hospitals.
The UK authorities ‘need more information on the specific strain circulating’ in order to accurately assess the threat to the British public, warned virus expert Dr Andrew Catchpole.
It comes as cases of the infection — which features cold-like symptoms — rise across the UK, with graphs showing doubling in numbers over the last month.
Currently, as many as one in 20 cases of respiratory infections could be due to the infection, which is known as human metapneumovirus (hMPV), according to the latest UK surveillance data.
‘hMPV is usually detected in the winter periods but it does seem that the rates of serious infection may be higher in China than what we would expect in a normal year,’ said Dr Catchpole, who is Chief Scientific Officer at infectious disease testing firm hVIVO.
‘We need more information on the specific strain that is circulating to start to understand if this is the usual circulating strains or if the virus causing high infection rates in China has some differences.’
He added: ‘It is unclear just how high the numbers are or if issues are arising purely due to coinciding with high flu and Covid levels.’
Promisingly, Dr Catchpole noted that while hMPV ‘does mutate and change over time with new strains emerging’, it is ‘not a virus considered to have pandemic potential’.
Latest UK data shows cases of the virus have seen a ‘marked increase’ in recent weeks – slightly higher than at the same time last year
Cases of hMPV have doubled in the last month in the UK, according to the UK Health Security Agency.
Speaking to MailOnline, multiple experts urged Brits not to panic, as the vast majority of infections cause ‘mild, cold-like symptoms’.
However, for those with compromised immune systems — very young children, the elderly and those with certain underlying conditions — the infection could lead to more serious disease.
‘In young children, the elderly and those who are immune compromised, hMPV can lead to severe cases and can move to the lower respiratory tract and may lead to pneumonia,’ warned Jaya Dantas, a professor of international health at Curtin University in Australia.
‘We need to use a cautious and measured approach, as we know so much more since the Covid pandemic.’
Beijing has downplayed footage of overcrowded waiting rooms and wards posted on social media, saying respiratory infections are ‘less severe’ and ‘smaller in scale’ compared to last year.
That has led some to fear there are similarities with the current situation and the Covid outbreak in 2019, which was initially minimised by China.
Although British experts have remarked that the scenes in Chinese hospitals appear little different to that of UK healthcare at this time of year.
The graph shows the proportion of visits to hospital for flu-like illness in northern provinces in China by week. The red line is for 2024-2025 flu season, and shows levels are at their highest since 2021
Scientists have urged the public to take precautions to limit the spread of hMPV, as well as the multiple other respiratory viruses known to be circulating.
‘We need to get tested, stay home and away from others, wear a mask in public and protect our most vulnerable,’ said Prof Dantas.
Meanwhlile Professor John Tregoning, an expert in vaccine immunology at Imperial College London added: ‘Protecting yourself by being in well-ventilated spaces, covering your mouth when you cough and washing your hands will all help.’
The calls for greater transparency from China follow a chorus of similar pleas from international experts.
Dr Sanjaya Senanayake, infectious disease expert associate professor of medicine at The Australian National University, said it was ‘vital for China to share its data on this outbreak in a timely manner’, including ‘data about who is getting infected.’
He added: ‘Also, we will need genomic data confirming that HMPV is the culprit, and that there aren’t any significant mutations of concern. Such genomic data will also guide vaccine development.’
Meanwhile the US has seen its own increase in HMPV cases, with positive test percentages doubling from the beginning to the end of December.
According to the latest CDC data, just under 300 positive test results reported during the last week of December, the latest figures available.
The US CDC said it is ‘monitoring’ the cases in China but believe they are ‘not currently a cause for concern in the US.’
The above is a grab from a video posted online claiming to show an overwhelmed hospital unit in China
The above CDC graph shows an increase in positive HMPV tests at the end of December 2024
hMPV first emerged in 2001 and typically causes symptoms of a common cold.
But more severe symptoms such as bronchitis, bronchiolitis and pneumonia can occur, with sufferers experiencing a shortness of breath, severe cough or wheezing.
Children, the elderly and immunocompromised patients are at the highest risk of severe complications.
Because the virus is usually mild, its exact death rate is unknown. But experts estimate anywhere from 10 to 30 percent of patients hospitalised with hMPV die.
Dr Senanayake cautioned that China’s increase in hMPV cases is akin to a ‘bad flu season’ and was not likely to escalate into a global problem.
He said: ‘At this stage, the likelihood is that China is experiencing a bad hMPV season, in the same way that in some years we have an overwhelming flu season.
‘This could be due to a combination of viral and behavioral factors, but it should settle down.’
Vasso Apostolopoulos, a professor of immunology at RMIT University in Australia, said the surge in cases and growing pressure on healthcare systems in densely populated regions like China shows a need for more surveillance.
She said: ‘Ensuring effective monitoring and timely responses will be key to mitigating the public health risks of this outbreak.’
The Chinese health authorities have urged people to take precautions like hand washing but has pushed back against claims that hospitals will be overwhelmed.
Chinese foreign ministry spokesperson Mao Ning said: ‘Respiratory infections tend to peak during the winter season.
‘The diseases appear to be less severe and spread with a smaller scale compared to the previous year.’
Similar to Covid, hMPV spreads through respiratory droplets that circulate in the air when a person coughs or sneezes. Close personal contact like shaking hands and touching contaminated surfaces can also spread the disease.
Fever, cough, congestion, and shortness of breath are the most common symptoms.
There are no vaccines or specific treatments for the disease.
Professor Tregoning said: ‘hMPV (human metapneumovirus) is not a new virus, it was first isolated in 2001 but most likely has been circulating for much longer.
‘It has very similar symptoms (in children at least) to RSV (respiratory syncytial virus). It is part of the cocktail of winter viruses that we are exposed to.
‘As with all respiratory viruses, there will be a range of symptoms and severity. Risk factors will include age (either very young or very old) and underlying immunosuppression.
‘Like other viruses it will transmit in coughs, sneezes and in droplets. Protecting yourself by being in well ventilated, covering your mouth when you cough, washing your hands will all help.
‘It will present in the same way as flu, sars-cov-2, RSV, so the same advice applies for those affected – rest, take on fluids, try not to spread it to others.’
The above are clips from videos claiming to show overwhelmed hospitals in China
Experts have cautioned that HMPV, which produces flu-like symptoms, can lurk in the body for days and so it can be easily passed on to others
Professor Jill Carr, a virologist in the College of Medicine and Public Health at Flinders University in Australia, cautioned the current outbreak in China was not likely to cause a global crisis.
She said: ‘This is very different to the COVID-19 pandemic, where the virus was completely new in humans and arose from a spill-over from animals and spread to pandemic levels because there was no prior exposures or protective immunity in the community.
‘The scientific community also has some understanding of the genetic diversity and epidemiology of hPMV, the kind of impact the virus has on the lungs and established laboratory testing methods – again, very different to the COVID-19 pandemic, where a new lung disease was seen, there was little information on how the virus may vary and spread and we had no initial diagnostic tests.’
Andrew Easton, a virology professor at the University of Warwick in the UK, told Live Science: ‘hMPV has been recognised as a significant problem in the at-risk population across the world since the turn of the century when it was first discovered.
‘That risk has not changed significantly over the last almost 25 years.’
Paul Hunter, professor in medicine at the University of East Anglia in the UK, said that it can be difficult to detect year-over increases in the virus because hMPV is detected with molecular tests like PCR tests, which are used to detect Covid.
He said: ‘One of the issues involved in these types of infection is that they are being diagnosed more frequently as we move to molecular diagnostic panels, so it is not always easy to know whether year on year increases are due to actual increases or just because we are diagnosing a greater proportion of infections.
He noted that while the UK has seen a ‘marked increase in recent weeks’, cases are roughly similar to this time last year.
He said: ‘So overall, I don’t think there is currently any sign of a more serious global issue.’
Dr Jacqueline Stephens, a senior lecturer in public health at Flinders University in Australia, said: ‘I think we’re just more cautious of outbreaks now.
‘Everyone is hypervigilant, and you hear this term human metapneumovirus and it sounds kind of scary.’
