HMN 2025: what you need to know about this virus

In the last few days there have been reports that another infectious disease is spreading rapidly in China. This time the virus is human metapneumovirus, abbreviated to HMPV.

There was demands in some media outlets to this increase in infections yes too many hospitals in China . On the other hand, the current wave of infections is not out of the normal for this time of yearaccording to the World Health Organization.

So what is the real case and what is HMPV anyway? HMPV is a respiratory virus in the same family as the more commonly known respiratory syncytial virus (RSV). It is not a new infection and has probably been circulating in humans for centuries.

The virus was first linked to human illness about 25 years ago with Dutch researchers who identified the virus in children with RSV-like illness. This same study showed that the virus was not new as archival samples from the 1950s showed that all children in the study had HMPV antibodies by their fifth birthday. Other research has suggested that HMPV diverged from avian MPV about 300 years ago.

Like all viruses, HMPV evolves over time. But his The rate of evolution is relatively slow compared to some other viruses.

HMPV is one of the most common respiratory viruses. Even after childhood, we can expect multiple chronic infections throughout life.

The disease is found worldwide, with most infections occurring during the winter months. The virus causes an illness that is very difficult to distinguish from many other respiratory infections without testing.

Most infections are a mild, cold-like illness, and people recover within about two to five days. However, in young children, the illness can be more severe and resemble the chest infection caused by RSV. HMPV is generally not a cause in children so severe illness such as RSV and are less likely to require admission to an intensive care unit.

In older adults (over 65), and those with certain pre-existing health conditions, HMPV can cause more severe diseases. This is especially true in people with heart and lung disease, including asthma.

There is no specific treatment for HMPV. Instead, patients are made comfortable until they recover on their own. If people become very ill the treatment is to support normal breathing.

There is no vaccine against HMPV. However, some vaccines i the process being developed. A a combined HMPV and RSV mRNA vaccine Trials have recently begun.

What is the current situation?

In the UK, there was a significant increase in HMPV positive samples in the weeks leading up to Christmas rising to 4.5% of the samples tested in the past week. The latest data from the first week of January suggests that the number of infections may have already peak and the percentage of positive samples is always around 4.5%.

In the same week, 21.9% tested positive for flu, down from 27.7% the previous week. The HMPV results for the same week last year and the year before about the same. So in the UK at least, the levels of HMPV infections seem to be about what we would expect at this time of year.

We will have to wait and see if HMPV infections decrease in January. The story is in the UK produced in the USAalthough US rates are still well below last winter’s peak.

In China, there are indeed reports of HMPV infections rising in recent weeks in the regions further north. But so are reports of all other respiratory pathogens including seasonal influenza, rhinovirus and RSV.

In China, influenza is the most commonly found respiratory virus, just like in the west. In its latest report, the World Health Organization suggested that, at present, the increase in respiratory pathogens in China “within the expected range for this time of year”. If health services are crumbling in China, the main concern is far more likely to be the flu.

So, I think we can be pretty confident that we’re not going to see a significant additional global risk from HMPV to public health.

The situation with HMPV is very different from the situation with COVID in early 2020. Unlike COVID, HMPV is not a new infection and most people have substantial immunity from many previous infections.

Also, the “F protein” – one of the main targets on the surface of HMPV that our antibodies call upon to neutralize it – has remained stable for decades, suggesting that change is unlikely new there.

But we should not be complacent about any infectious disease so we must continue to monitor what is happening in China and change our risk assessments if necessary.