Rising HMPV Cases Nationwide in Late Winter

Cases of human metapneumovirus, a common respiratory virus with no vaccine or specific treatment, are rising across the United States as late winter approaches its typical peak season. According to data from the Centers for Disease Control and Prevention, the virus has been detected nationwide, with notable increases in California, the Great Lakes region, and New Jersey.

The National Respiratory and Enteric Virus Surveillance System reported that 5 percent of positive tests for respiratory viruses in the week ending February 28 were for human metapneumovirus, or HMPV, marking the highest level since mid-2023. This figure trails influenza and respiratory syncytial virus but exceeds that of COVID-19. In California, test positivity reached 8.6 percent that week, surpassing levels from four of the past five respiratory seasons, state health officials said. Wastewater monitoring has shown elevated concentrations in Northern California communities, including San Francisco, Sacramento, Davis, and Vallejo.

HMPV causes upper and lower respiratory infections similar to those from the flu or common cold. Common symptoms include cough, fever, nasal congestion, sore throat, wheezing, and...