HMPV virus – latest: US monitoring China cases as Bali steps up checks on flights

Jill Carr, a virologist in the College of Medicine and Public Health at Flinders University, Australia, said the situation is “very different to the Covid-19 pandemic”.

She told Politico: “The virus [Covid-19] 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.”

A disease expert has urged China to share infection data amid an outbreak of human metapneumovirus (HMPV) which has spread across four countries.

Dr Sanjaya Senanayake, infectious disease expert associate professor of medicine at The Australian National University, said it was “vital” for China to share information in a “timely manner”.

“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,” he told MailOnline.

HMPV (human metapneumovirus) spreads through direct contact with infected individuals or by touching contaminated surfaces, experts say.

Unlike viruses like flu, RSV, and Covid-19, there is no vaccine for HMPV, Dr Carla Garcia Carreno, director of infection prevention and control at Children’s Medical Center in Plano, Texas says. “We don’t have that advantage of priming or boosting our immune system to fight these viruses. But still, everything else that we learned for Covid can apply to metapneumovirus.”

She told CBS News: “If somebody’s sick, try to avoid crowding so they don’t expose everybody, especially the vulnerable people. If that person is sick and can not avoid going to a place where other people are, then try to use a mask, use cough and sneezing etiquette and good hand washing.”

Prof Paul Hunter, professor in medicine at the University of East Anglia, has offered reassurances that there are no signs of a more serious global issue with HMPV, despite a recent increase in diagnoses in England.

He told the Science Media Centre: “In England we have seen a fairly marked increase in recent weeks – so far the peak per cent positivity is a little over what it was this time last year so no major difference to usual, unless infections positivity rates continue to increase in coming weeks.

“So overall, I don’t think there [are] currently any signs of a more serious global issue.”

He added: “HMPV is a quite common respiratory infection that peaks in winter. Almost every child will have at least one infection with HMPV by their fifth birthday and we can expect to go on to to have multiple reinfections throughout life.”

Prof Sir Andrew Pollard, an expert on infections and immunity at the University of Oxford, says that HMPV mostly affects babies and the elderly. “In most other age groups it simply causes the symptoms of a cold,” he tells the Science Media Centre.

“Human metapneumovirus virus is a common respiratory virus which was first identified almost a quarter of a century ago by Dutch scientists,” Sir Andrew says.

“It is one of the many viruses which circulate in the winter and add to the winter pressures on the NHS.

“The reports of respiratory infections in China in the past few days appear to be attributed to both influenza and this human metapneumovirus, which is rather similar to the situation in the UK this week. A vaccine for a similar virus, RSV, was launched by the NHS in 2024 and new vaccines are being developed which could protect against both RSV and human metapneumovirus in one jab.”

Currently, there are no antiviral medications specifically for HMPV. Treatment focuses on supportive care to manage moderate or severe symptoms, according to experts.

“If you’re wheezing, we’ll give bronchodilators,” Dr Peter Chin-Hong, an infectious diseases specialist at the University of California, San Francisco, told ABC News, referring to medications that relax and open airways while helping to clear mucus from the lungs.

“If you’re dehydrated, we provide fluids, and we work to reduce the fever.”

Dr Chin-Hong also noted that co-infections, such as bacterial infections, can occur in some cases, which may require antibiotics for treatment.