Hmpv Detected in California Wastewater as Officials Urge Monitoring Across Northern Communities
Human metapneumovirus is appearing at elevated levels in parts of California’s wastewater, and officials say there is no vaccine or specific treatment. Wednesday at 11: 22 a. m. ET, WastewaterScan Dashboard data show hmpv increases in Merced, Novato and Sunnyvale, a trend public health officials are monitoring as seasonal respiratory illnesses return.
Hmpv Levels in Merced, Novato and Sunnyvale
A data analysis found communities in Merced in the San Joaquin Valley and Novato and Sunnyvale in the San Francisco Bay Area saw increases in hmpv levels between mid-December and the end of February. A majority of Northern California communities registered high concentrations in wastewater during that span, while L. A. County detections so far remain at low to moderate levels.
WastewaterScan Dashboard Detects Hmpv Across Northern California
WastewaterScan Dashboard, a public database that monitors sewage to track infectious diseases, identified elevated human metapneumovirus signals used in the analysis. HMPV was first detected in 2001, the U. S. Centers for Disease Control and Prevention notes, and the virus spreads through close contact with infected people or by touching contaminated surfaces, said Dr. Neha Nanda, chief of infectious diseases and hospital epidemiologist for Keck Medicine of USC.
Experts at Keck Medicine of USC and Kaiser Describe Hmpv Seasonality
Infectious-disease specialists say HMPV’s typical seasonal pattern was disrupted by the COVID-19 pandemic. Dr. Jessica August, chief of infectious diseases at Kaiser Permanente Santa Rosa, said human metapneumovirus cases commonly start showing up in January, peak in March or April and then tail off in June. National test-positivity figures have varied: a recent peak of 11. 7% occurred at the end of March in one year, 7. 15% was recorded in late April the following year, and this year’s highest documented test positivity was 6. 1% on Feb. 21, the most recent date with complete data.
August said the pandemic reduced routine exposure and natural immunity, contributing to sharper post-pandemic surges in childhood viral illness: “That’s why after the pandemic we saw record-breaking childhood viral illnesses because we lacked the usual immunity that we had, just from lack of exposure, ” she said.
Officials emphasize surveillance and preventive measures as the region moves into the expected seasonal window. Cases typically peak in March or April and decline by June, per Dr. August; public health monitoring will continue through that period to track whether wastewater and clinical trends align.
