Norovirus-related illnesses linked to eating oysters, reveals report

Dec 7 2009

FDA, CDC, and States Investigating Norovirus Illnesses Linked to Oysters
Consumers advised to avoid oysters harvested from San Antonio Bay

The U.S. Food and Drug Administration is advising consumers to avoid eating oysters harvested from the San Antonio Bay on or after Nov. 16 due to reports of norovirus-associated illnesses in some people who had consumed oysters harvested from this area, which is located on the Gulf of Texas.

The FDA, along with the Centers for Disease Control and Prevention (CDC) and the states of North Carolina, South Carolina and Texas, are investigating about a dozen reports of norovirus-related illnesses from South Carolina and North Carolina consumers who ate oysters recently harvested from the San Antonio Bay.

Consumers who purchased oysters on or after Nov. 16 that have a label showing they came from San Antonio Bay are advised to dispose of the oysters and not eat them. At restaurants, consumers can ask about the source of oysters offered as menu items. Restaurant operators and retailers should not serve or offer for sale oysters subject to this advisory. Restaurant operators and retailers who are unsure of the source of oysters on hand should check with their suppliers to determine where the oysters were harvested. No other seafood is affected by this advisory.

The Texas Department of State Health Services has ordered a recall of all oysters harvested from the San Antonio Bay between Nov. 16 and Nov. 25.

Noroviruses are a group of viruses that cause gastroenteritis. Symptoms of illness associated with norovirus include nausea, vomiting, diarrhea and stomach cramping. Affected individuals often experience low-grade fever, chills, headache, muscle aches and a general sense of tiredness. Most people show symptoms within 48 hours of exposure to the virus. The illness typically lasts one to two days. Norovirus typically is not life-threatening and does not generally cause long-term effects.

Consumers who ate oyster products on or after Nov.16 and have experienced symptoms of norovirus are encouraged to contact their health care provider and local health department.

The implicated oyster beds in the San Antonio Bay were closed by the Texas Department of Health Services on Nov. 26, 2009, and remain closed. 

The FDA and CDC will continue working with health officials in the affected states to track any additional cases of norovirus illness.

Persons with weakened immune systems, including those affected by AIDS, and persons with chronic alcohol abuse, liver, stomach or blood disorders, cancer, diabetes or kidney disease should avoid raw oyster consumption altogether, regardless of where the oysters are harvested.