San Diego County saw a surge in foodborne illness outbreaks last year, with cases more than doubling from 24 in 2023 to 50 in 2024. Health officials point to outbreaks tied to contaminated oysters and raw milk as key contributors to the increase. An outbreak is two or more illnesses from the same food source.
Dr. Mark Beatty, assistant medical director for the county’s epidemiology team, called 2024 a "big year" for norovirus.
"Norovirus ends up accounting for the fair majority of the cases that lead to these outbreaks," he said.
Norovirus, a highly contagious virus that causes vomiting, diarrhea and stomach pain, was identified in 15 outbreaks linked to raw oysters from Mexico and Washington state.
Since 2019, 81% of foodborne illness outbreaks in San Diego County have been linked to restaurant-prepared food, according to county data.
Heather Buonomo, director of environmental health and quality for the county, and her team investigate complaints of suspected foodborne illness from both medical providers and the public.
"Our team will do a little diet recall. We'll talk to them about everything they've eaten in the past few days and try to get more information to determine if, you know, their symptoms were caused by a food that they consumed from a restaurant," she said.
Another major outbreak involved raw milk. In 2023, it was linked to salmonella. Last year, health officials investigated it for possible bird flu. Beatty said a small cluster of cases helped the county detect a larger issue statewide.
"When we realized that we had four people who had all said they drank raw milk, which is not that common to encounter, we knew that there was something going on," he said.
Since 2019, the county has investigated 166 foodborne illness outbreaks that sickened over 1,100 people and hospitalized 27. Some outbreaks were small, with just two cases, while others affected up to 68 people.
Buonomo said simple precautions can help reduce the risk.
"Hot food, keep it hot. Cold food, keep it cold. And washing your hands are really going to be some of the best preventative measures," she said.
Preventing outbreaks isn’t just up to health officials said Mitzi Baum, CEO of Stop Foodborne Illness. She advocates for stronger food safety policies and consumer education.
"We all have a role to play in reducing illness and death associated with foodborne illness, Baum said. “Consumers need to be educated and informed as well."
Health officials encourage people to report suspected cases of foodborne illness to help track outbreaks and prevent further cases.
