
San Francisco Faces a Viral Crunch: Rotavirus and Others Surge, with Unclear Causes
San Francisco is seeing a surge of multiple viruses—rotavirus, norovirus, HMPV, influenza A/B, and RSV—driving illness in the Bay Area even as COVID-19 remains low, according to WastewaterSCAN data. Rotavirus is notably higher in 2026, a trend experts say could reflect better wastewater tracking or lower vaccine uptake; the CDC no longer routinely recommends rotavirus vaccination, leaving decisions to clinicians and families. Health officials advise basics like hand-washing and staying up to date on vaccines, while researchers note that waning immunity and a new flu strain may be prolonging winter viruses into spring.










