As China continues to monitor an increase in cases of human metapneumovirus (HMPV), here's what you need to know about the illness.

While cases are climbing in China, the situation is very different from what it was when Covid-19 emerged five years ago, medical experts say. HMPV has circulated in humans for decades.

As China experiences a rise in respiratory infections this winter, one little-known virus has gotten a lot of attention – and some people may worry whether the rise in cases could be felt more broadly around the world.

In China, reports of HMPV infections have indeed been rising in recent weeks in the more northerly regions. But so have reports of all the other respiratory pathogens including seasonal flu, rhinovirus and RSV.

Five years after the first cases of COVID-19, reports of hMPV, an obscure respiratory virus in China may understandably raise concerns.

Plenty of viruses are having their strongest season for years. But experts have urged calm about HMPV, which is not a new disease — even if you've never heard about it.

Symptoms of HMPV are similar to that of the common cold and can include a cough, fever, runny nose, sore throat, wheezing, shortness of breath and a rash. It can also cause upper and lower respiratory infections.

Experts say the disease is likely not going to be the next pandemic and the worry is a result of heightened wariness for respiratory illness in a post-Covid world. HMPV is a respiratory virus that regularly circulates during cold and flu season.

WHO said, ‘Human metapneumovirus, hMPV is not a new virus’, adding that it generally spreads in winter and spring.