What Is Human Metapneumovirus, and Why Are Cases Rising in China?

HMPV Cases Are Rising Across Asia, but Experts Say Not to Panic

By Lauren J. Young edited by Dean Visser

Cases of a common respiratory virus called human metapneumovirus, or HMPV, are surging in several Asian countries, but experts say the situation shouldn’t trigger fears of a larger global health threat. HMPV falls into the same mix of winter bugs as influenza and respiratory syncytial virus (RSV), which often peak during this time of year in the Northern Hemisphere. Common HMPV symptoms, such as a runny nose, coughing and fever, are typically mild. Young children, older adults and people who are immunocompromised may be at a higher risk of severe disease, however.

In mid-December 2024 health agencies in China reported an overall increase in respiratory infections, including an HMPV uptick in children under 14 years old in northern China. Reports of a hospital allegedly flooded with cases further fueled alarm and attention to this lesser known yet common winter respiratory disease.

“In Asia, they are having a fairly large outbreak—might even call it an epidemic—of human metapneumovirus,” says William Schaffner, an infectious disease physician and a professor at Vanderbilt University Medical Center. “There’s no need to be panicky. But for those folks who are in higher-risk groups, this is a time to be careful, [to] be cautious.”

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China’s relatively large case count has prompted the nation and nearby countries to increase surveillance. Cases have also been detected in Malaysia, India and Kazakhstan. Experts note that HMPV has been occurring in humans around the world for decades, however.

“The virus has circulated for at least 60 years, and genetic evolutionary studies suggest that it diverged from a bird virus between 200 to 400 years ago,” says John Williams, a pediatrician and infectious diseases professor at the University of Wisconsin–Madison, who has…