The California Department of Public Health (CDPH) https://www.cdph.ca.gov/ says oysters harvested from Baja California Sur, Mexico are linked to a gastrointestinal illness outbreak in California. The CDPH said 12 people between [February and April 2019] have reported getting sick after eating raw oysters from stores and restaurants in San Diego County, Los Angeles County, Orange County, and Santa Barbara County.
The investigation is ongoing, but so far, laboratory testing of oysters harvested from Estero El Cardon revealed 6 different toxic pathogens, including non-O157 Shiga toxin-producing _E. coli_ https://www.fda.gov/food/foodborne-pathogens/bad-bug-book-second-editionMexican authorities are also investigating.
The CDPH says shellfish sold at stores and restaurants are required to have tags indicating where the product is from. People who become ill after eating raw oysters or undercooked shellfish should contact a doctor, the CDPH says. The CDPH also says shellfish should be cooked to at least 145 degrees Fahrenheit internal temperature. The department also warns against quick steaming.