Unknown Respiratory Virus Surged in U.S. This Spring as COVID-19 Declined

Cases of human metapneumovirus (HMPV), a little-known respiratory illness, spiked in the United States this spring.
Nearly 20% of tests for HMPV came back positive in March, a 36% increase, while COVID-19 cases fell by 30%.
HMPV causes cold-like symptoms in most but can lead to pneumonia or bronchitis, especially in young children, older adults, and those with weakened immune systems.
There is no vaccine or treatment for HMPV, which spreads through airborne particles, physical contact, and contaminated surfaces.
People are advised to wash hands, avoid close contact with the sick, and not touch eyes, nose or mouth to prevent infection.