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.

China’s winter illness season is less severe compared to the year before, according to data from its health authority. But the proliferation of a long-standing though little-known pathogen called human metapneumovirus (hMPV) has been raising alarm both at home and in other countries.

Cases of human metapneumovirus, or HMPV, are in the U.S. too, and it looks similar to other seasonal illnesses. Here's what to know before you panic.

Five years on from the first news of COVID, recent reports of an obscure respiratory virus in China may understandably raise concerns. Chinese authorities first issued warnings about human metapneumovirus (hMPV) in 2023,