Wash those hands extra well, as portions of the Bay Area are experiencing spikes in norovirus infections, the highly contagious gastrointestinal bug that’s typically foodborne, including parts of San Francisco, Marin County, and Silicon Valley.
As SFGate reports, based on data from WastewaterSCAN, higher levels of norovirus infections were detected in the wastewater of the western side of San Francisco, as well as Central Marin County, Novato, and Redwood City. Based on the site’s line graph data, moderate levels were found on the eastern side of SF, Santa Rosa, Vallejo, San Jose, and Palo Alto.
Common norovirus symptoms include vomiting, diarrhea, and stomach cramps, along with fever, headache, and body aches, which typically develop 12 to 48 hours after exposure, according to the US Centers for Disease Control. The virus can lead to dehydration, especially in small children and elderly adults, and it’s advised to drink plenty of fluids, including electrolyte beverages and oral rehydration drinks depending on the severity.
The virus, which is highly contagious, is typically spread through contaminated surfaces and food, as well as coming into contact with those with the virus. The CDC also warns that raw shellfish, including oysters, can also carry the norovirus.
“It is extremely contagious,” Dr. Monica Gandhi, an infectious disease specialist at UC San Francisco, told SFGate, emphasizing that hand-washing is essential. “And people don’t wash their hands, especially kids.”
Per SFGate, the norovirus is often referred to as the “cruise ship bug.” As CBS News reports, more than 150 people became infected onboard a Princess cruise ship last week — out of about 7,000 passengers and crew members, originating in Fort Lauderdale, Florida and sailing through the Caribbean.
In February, there was an outbreak of an "unknown gastrointestinal illness" infecting 27 people aboard the luxury cruise ship, the Regent Seven Seas, which sailed from Miami to Honolulu. Last December, more than 80 people contracted the norovirus on board a Holland America cruise ship, also originating in Fort Lauderdale, as CBS reports.
The site Global Biodefense reports that in 2024, 16 cruise ships encountered outbreaks of gastrointestinal disease, including five in December 2024 alone — reportedly the largest number of outbreaks in 12 years.
