Health Experts Warn Travelers Visiting This California City They May Leave With More Than Just Their Souvenirs
If you're planning a trip to San Francisco this spring or summer, health experts are urging travelers to take extra precautions. The city is currently seeing a surge in multiple viruses, including a notable rise in rotavirus, raising concerns about how easily illnesses could spread among visitors.
While this doesn't mean you should cancel your trip, it does mean you should travel smarter.
A Surge in Multiple Viruses
Recent data from WastewaterSCAN show that San Francisco is experiencing elevated levels of several viruses simultaneously, including rotavirus, norovirus, influenza, and RSV.
Among these, rotavirus is drawing particular attention. Typically associated with young children, this highly contagious gastrointestinal illness causes symptoms like severe diarrhea, vomiting, and fever, and in serious cases, dehydration requiring hospitalization.
Wastewater monitoring across the Bay Area shows that rotavirus levels are significantly higher in 2026 than last year, with San Francisco among the top cities reporting ongoing transmission.
Even more concerning, this spike is occurring alongside other lingering viruses, meaning travelers could be exposed to multiple illnesses in crowded environments such as airports, hotels, and public transit.
Why Experts Think Cases Are Rising
Health officials say there isn't just one reason behind the surge, but rather it's a combination of factors.
One major concern is the decline in vaccination rates.Rotavirus vaccines, once routinely recommended for infants, are now subject to more individualized decision-making, which experts worry could reduce overall immunity.
At the same time, broader vaccine hesitancy and lower uptake of routine immunizations may be contributing to the spread of multiple viruses, not just rotavirus.
Another factor is timing. Rotavirus typically peaks in late winter and early spring, and experts believe lingering low immunity levels may be allowing viruses to persist longer into the year than usual.
Improved wastewater surveillance is also detecting more cases than in previous years, which means the spike may be partly due to better tracking, but that doesn't make the risk any less real.
Related: Health Officials Are Warning Travelers to Avoid These Popular Hawaiian Beaches Right Now
Why Travelers Should Pay Attention
For most healthy adults, rotavirus is usually mild. But it can still disrupt a trip with unpleasant symptoms, and for families traveling with young children, the risks are much higher.
The virus spreads through what's known as the fecal-oral route, meaning it can be transmitted by touching contaminated surfaces, food, or water and then touching your mouth.
That makes it especially easy to pick up while traveling, where shared spaces and high-touch surfaces are everywhere, from airplane tray tables to hotel elevators. Add in the presence of other viruses circulating in the city, and the likelihood of getting sick while traveling increases.
Tips for Staying Healthy While Traveling
The good news is that protecting yourself is relatively straightforward if you stay consistent.
- Wash your hands frequently: Hand hygiene is your first line of defense. Wash with soap and water, especially before eating and after using public spaces. Hand sanitizer helps, but it's not always enough against viruses like rotavirus.
- Be cautious with food and drinks: Stick to reputable restaurants, avoid sharing utensils, and be mindful of surfaces when eating on the go.
- Disinfect high-touch items: Wipe down airplane seats, tray tables, and hotel surfaces when possible. Viruses can live on surfaces longer than you might expect.
- Stay up to date on vaccinations: Talk to your doctor before traveling, especially if you're traveling with children. Vaccination remains one of the most effective ways to prevent severe illness.
- Don't ignore symptoms: If you start feeling sick, prioritize rest and hydration. In more serious cases, especially for children, seek medical attention quickly.
San Francisco remains one of the most exciting destinations in the U.S., but the current rise in viruses is a reminder that travel always comes with some health risks.
By staying informed and taking simple precautions, you can still enjoy everything the city has to offer, from iconic landmarks to its world-class food scene, without letting illness derail your trip.
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This story was originally published April 21, 2026 at 10:12 AM.