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.

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

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.

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.

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