Rotavirus, the intestinal virus that can trigger violent vomiting and life-threatening dehydration in babies and toddlers, is making an unwelcome surge in parts of Northern California. Sewage monitoring and local experts report rising community spread in several Bay Area cities just as federal vaccine guidance has shifted, putting pediatricians on high alert. Parents are being urged to watch closely for rapid fluid loss in young children and to seek care quickly if symptoms start.
“It’s extremely contagious,” UC San Francisco infectious-disease specialist Dr. Monica Gandhi told SFGATE. UCSF’s California Childcare Health Program estimates that roughly 50,000 U.S. children are hospitalized with rotavirus each year, with infants and toddlers hit the hardest. The virus spreads by the fecal-oral route and can survive on surfaces, which makes day-care centers and other crowded settings especially risky, according to UCSF.
Wastewater Data Flags a Local Spike
Municipal wastewater testing has picked up elevated levels of rotavirus RNA around the region, with WastewaterSCAN reporting high detections in Davis, Marin, Redwood City, San Jose and Fremont, and moderate levels in San Francisco, Sunnyvale and Novato. Wastewater surveillance detects viral material shed in stool and often gives public health teams an early warning that community transmission is on the rise. Local health departments typically combine those signals with clinic and hospital reports to fine-tune outreach and testing.
Vaccine Guidance Has Shifted
In January 2026, the Department of Health and Human Services and the CDC moved rotavirus vaccination into a shared clinical decision-making category, advising that parents talk through the shot with their child’s clinician, according to the CDC. The agency also details two oral rotavirus vaccines, RotaTeq (first licensed in 2006) and Rotarix, that are effective at preventing severe illness, as outlined by the CDC. Major pediatric groups have criticized the policy change and said they will continue to recommend routine vaccination, as reported by AJMC.
What Parents Should Do
Health experts say the basics still matter: keep sick children home, enforce careful hand-washing and disinfect high-touch surfaces if someone in the household is ill. Offer oral rehydration solutions, for example Pedialyte, and call a pediatrician at the first sign of decreased urine output, dry mouth or sunken eyes. Early treatment for dehydration can prevent hospitalization.
If you have questions about vaccinating an infant, discuss the risks and benefits with your child’s clinician. UCSF recommends immunization as the most practical way to prevent severe rotavirus disease, according to UCSF…