HMPV Respiratory Virus Cases Spike Across Multiple US States
A lesser-known respiratory virus, human metapneumovirus (HMPV), is experiencing a significant surge in cases across several US states, including Georgia and Northern California, with no available vaccine or specific treatment. According to recent data, this pneumonia- and bronchitis-causing infection accounted for 6.4 percent of positive respiratory virus tests in Georgia during the first week of March, a notable increase from the three percent positivity rate recorded at the same time last year.
Widespread Detection and Rising Trends
Wastewater testing in Northern California, as monitored by the public database WastewaterScan Dashboard, indicates continuing rises in HMPV levels, serving as an early detection tool for virus spread. Although New Jersey has seen a recent decline in positive tests, overall levels across the United States remain higher than those observed during the same period in the previous year. Nationwide, HMPV made up more than five percent of positive respiratory virus tests for the week ending March 7, according to the U.S. Centers for Disease Control and Prevention (CDC), with testing positivity at 3.82 percent in early March 2025.
Understanding HMPV and Its Seasonal Patterns
First identified in 2001, HMPV is a seasonal virus that typically circulates during the winter and spring months. Cases in the U.S. have been trending upward since October 2025, with a new study revealing that the virus peaks later than influenza, often in April. Infection generally results in cold-like symptoms that persist for a few days to a week, but it can also lead to more severe complications such as middle ear infections, life-threatening asthma attacks, and a barking cough. In rare instances, HMPV can be fatal for vulnerable groups, including infants, the elderly, and immunocompromised individuals.
Health Risks and Hospitalization Rates
A federal report from 2025 highlighted that an estimated 12 hospitalizations per 100,000 people occurred annually from 2016 to 2019 due to HMPV. Dr. Andrew Thornton, a physician with Wellstar in Cobb County, Georgia, emphasized that HMPV tends to be more severe than milder viruses like rhinovirus, with outcomes heavily influenced by a patient's existing medical conditions and immune status. The Mayo Clinic notes that nearly everyone will contract at least one strain of HMPV in their lifetime, and the Cleveland Clinic adds that individuals older than five have likely already been infected at least once.
Prevention and Public Health Recommendations
Unlike influenza and RSV, there are currently no vaccines to prevent HMPV infections, which are diagnosed through laboratory testing. The virus spreads via direct contact, sneezing, coughing, or touching contaminated surfaces. To mitigate infection risks, the CDC advises regular handwashing with soap, thorough cleaning of surfaces, and staying home when feeling unwell. Dean Blumberg, chief of pediatric infectious diseases at U.C. Davis Health, underscores that following good respiratory hygiene, such as taking precautions when experiencing cold-like symptoms, is crucial for preventing the spread of HMPV.
