The California Department of Public Health is recommending that consumers avoid eating raw oysters harvested from Estero El Cardon in Baja California Sur, Mexico, because they are linked to an outbreak of gastrointestinal illnesses in California.

A dozen people reported illness in February, March, and April after consuming raw oysters sold by restaurants and retailers in Los Angeles, Orange, Santa Barbara, and San Diego Counties. The raw oysters have been distributed throughout the state.

Laboratory testing was performed for eight patients and multiple pathogens were identified: Vibrio parahaemolyticus in 3, Vibrio albensis in 1, Vibrio species unidentified in 1, Shigella flexneri serotype 1 in 2 cases, and norovirus in 1. One of the Vibrio parahaemolyticus patients was co-infected with non-O157 Shiga toxin-producing E. coli. The investigation is ongoing.

CDPH continues to work closely with local health jurisdictions to collect information about the sick people. Traceback evidence collected to date confirms that the oysters were harvested from Estero El Cardon. Shellfish authorities in Mexico have been notified about the outbreak and are investigating.

Restaurants and retailers can protect customers by checking their inventory and shellfish tags that are required to identify the source to avoid any raw oysters harvested from Estero El Cardon in Baja California Sur, Mexico. This will ensure that potentially contaminated raw oysters are not available for purchase, and any leftover contaminated products are discarded. Consumers should ask the retailer or restaurant about the source if the product is not labeled or identified.

California residents should visit their doctors if they become ill after eating raw oysters. Any illness should also be reported to the local health department. Some tips to remember include:

• Avoid eating raw and undercooked shellfish, including oysters, to reduce the risk of illness.
• If you do eat shellfish, cook it until it reaches an internal temperature of at least 145°F. A quick steaming isn’t sufficient to prevent gastrointestinal illness from these pathogens.”