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.

Professor Paul Hunter from the University of East Anglia notes that almost every child contracts HMPV by five years of age, with reinfections occurring throughout life. “HMPV typically causes cold-like symptoms that recover by themselves within 2 to 5 days. Severe cases are rare but can occur in vulnerable groups,” he says.

The Centers for Disease Control and Prevention says there is a reported spike in human metapneumovirus (HMPV) in China, and they are monitoring it closely.

HMPV is a respiratory disease that causes flu or cold-like symptoms. However, it can increase risks or lead to more serious complications like bronchitis or pneumonia, particularl