Cases of human metapneumovirus (HMPV) and other seasonal viruses are on the rise across the northern hemisphere in early 2025, according to the World Health Organization. While news reports and social media videos have caused concern about a potential HMPV outbreak in China,

Another similarity to COVID: A case of HMPV can last about a week, with symptoms peaking around the third day, Dr. Hoy told us. However, you can still be contagious for several days after you're feeling better and your symptoms subside. This is especially the case for patients with compromised or weakened immune systems.

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.