Authorities in China said they are monitoring cases of human metapneumovirus, or HMPV, after a reported increase inside the country, according to Reuters. Although cases are increasing at a rapid rate,

Cases of human metapneumovirus, or HMPV, a contagious virus that can lead to respiratory disease, is reportedly spiking in northern China. Infectious disease experts say risk to the U.S. is low.

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.