​CDPH Warns of Possible Norovirus Infections from Imported Raw Korean Oysters ​

March 18, 2025 

SN25-001 

​​​​What You Need to Know: CDPH is warning distributors and retailers not to sell and serve frozen raw oysters from Dai Hung Mulsan (KR 7 SP) in Tongyeongsi, Republic of Korea because they may be linked to outbreaks of norovirus illnesses in California. These oysters were sold at restaurants in Southern California.  ​

Sacramento – The C​alifornia Department of Public Health (CDPH) is warning distributors and retailers not to sell or serve frozen raw oysters from Dai Hung Mulsan (KR 7 SP) in Tongyeongsi, Republic of Korea (ROK) because they may be contaminated with norovirus, a virus that can cause gastrointestinal illness.  

As of March 10, 2025, 13 confirmed and probable cases of norovirus have been reported among persons who consumed raw oysters from the ROK at four restaurants in late February and early March 2025. Investigations by public health officials in affected counties and CDPH have identified frozen raw half shell oysters as the likely source.  

Restaurants and retailers can protect customers by checking their inventory and shellfish labels, ensuring that potentially contaminated raw oysters are not available for purchase, and discarding any leftover contaminated product. 

The importer, Sea Win, Inc in Los Angeles, CA has issued a voluntary recall of the frozen raw half shell oysters. CDPH is working closely with local health departments and anticipates additional cases linked to these oysters.   

How to Protect Yourself from Norovirus   

Anyone who becomes ill after eating raw oysters should contact their health care provider and report the illness to their local health department. To reduce the risk of illness, particularly for people susceptible to severe disease or who have underlying medical conditions, people should avoid eating raw and undercooked shellfish, including oysters. If you eat shellfish, cook it until it reaches an internal temperature of at least 145°F. Quick steaming isn't sufficient to kill norovirus.   

Norovirus is a highly contagious virus and can be spread easily from person-to-person, through contaminated surfaces and by eating contaminated food, including raw or undercooked oysters. Symptoms of norovirus usually begin 12 to 48 hours after a person has come in contact with the virus and can last for 1 to 3 days. Common symptoms include vomiting, diarrhea, nausea, and stomach cramps.  

Norovirus cannot be treated with antibiotics and most norovirus infections resolve without need for medical care. Those with severe symptoms or at risk for severe disease should consult their health care providers. For more information on norovirus, please see CDPH's norovirus webpage.    

The most current information on shellfish advisories and quarantines are available at CDPH's toll-free Shellfish Information Line at (800) 553-4133. For additional information, please visit the CDPH Shellfish Advisories Web page.  ​​​​​​​