Raw oyster warnings after Southern California diners sickened

After dozens of reports of illnesses potentially linked to raw oysters, public health officials across Southern California are warning consumers to ask where the shellfish at their favorite seafood joint comes from.

The Los Angeles County Department of Public Health reported more than 150 suspected local cases of gastrointestinal illness linked to the consumption of raw oysters, up from 27 cases reported last week.

The Orange County Health Care Agency became the latest in the region Tuesday to warn its residents about consuming raw oysters after San Diego and Los Angeles counties reported norovirus illnesses that may be linked to imported shellfish harvested and packaged in Sonora, Mexico.

Los Angeles County public health officials are extending the cautionary note to raw oysters from Laguna de Guerrero Negro and Laguna Manuela, towns in Baja California, Mexico.

The warnings began last month, when San Diego County reported 41 confirmed and probable cases of norovirus illness potentially linked to raw oysters consumed in local restaurants. Those restaurants have not been identified by public health officials.

Last week, the U.S. Food and Drug Administration advised restaurants and retailers not to serve or sell oysters distributed by Sociedad Acuicola GolPac that were harvested on Dec. 18 or Dec. 27 due to potential norovirus contamination.

Oysters contaminated with norovirus can cause illness if eaten raw, and potentially severe illness in people with compromised immune systems, according to the FDA.

Foods show no outward signs when they are contaminated with norovirus, but once a contaminated food is consumed, it can cause symptoms including diarrhea, abdominal cramps, nausea, vomiting and fever. Symptoms usually develop within 12 to 48 hours after exposure to the virus. Most people with norovirus get better within one to three days.

Severe cases can lead to dehydration and are more likely to occur in young children, older adults and people with other illnesses.

Workers clean oysters in the state of Nayarit, Mexico. Health officials believe the contaminated oysters are linked to a distributor in Sonora state.

(Cesar Rodriguez / Bloomberg via Getty Images)

The Los Angeles County Department of Public Health, in collaboration with the California Department of Public Health, is still investigating the source of the recent cluster of gastrointestinal illnesses. The Times’ request for more information on the establishments related to the reports of illness was not received by publication time.

“Until the source is confirmed, consumers should be cautious before eating raw oysters due to the potential risk of food-borne illness,” said Dr. Muntu Davis, Los Angeles County health officer, in a news release. “If you are sick, avoid spreading illness by washing your hands frequently and cleaning frequently touched surfaces such as doorknobs, light switches, and kitchen countertops.”

Anyone who becomes sick after consuming food or drink should first seek medical attention and then report the incident to their county health department, public health officials said.

Los Angeles County residents who fall ill after food or beverage consumption are asked to file an online report. Orange County residents should report such illness by emailing fillness@ochca.com or calling (714) 433-6418. San Diego County residents are asked to call (858) 505-6814 or send an email to fhdepi@sdcounty.ca.gov.