Raw bar patrons got a heads up from the U.S. Food and Drug Administration (FDA) Saturday.

FDA said oysters recently harvested from Louisiana’s Area 7 on the Gulf of Mexico near the mouth of the Mississippi River at Port Sulphur are responsible for an outbreak of norovirus.

The federal agency is working with the states of Mississippi and Louisiana to get the word out to consumers about the contaminated oysters, which are sold and distributed nationwide.

Public health officials say consumers should not purchase or eat oysters from Area 7, and they are warning retailers and food-service operators not to sell or serve them.

Oysters harvested on March 10 from Area 7 made almost a dozen people sick in Mississippi, state officials told FDA.

Norovirus is a foodborne pathogen that can cause acute gastroenteritis in humans.

The Louisiana Department of Health and Hospitals has recalled oysters harvested from Area 7 from March 6 through March 24, 2010.

State health officials closed the area to harvesting on March 24 to protect the public health.

Public health officials are currently working to investigate potential sources of pollution that may have caused the area to become contaminated.

Consumers who are uncertain about the origin of oysters they have in their possession should contact the place of purchase to determine if the oysters are from the affected area.

Retailers and food service operators can check the tag or labeling that should accompany all raw molluscan shellfish to verify their origin.

Eleven people reported becoming sick after eating raw oysters at a conference center in Jackson County, MS.

Test results by the Mississippi State Department of Health confirmed that the patients were infected with norovirus.  

More advice from FDA follows:

Symptoms of norovirus illness usually include nausea, vomiting, diarrhea, and some stomach cramping. Sometimes people also have a low-grade fever, chills, headache, muscle aches, and a general sense of tiredness. The illness often begins suddenly, and the infected person may feel very sick. In most people the illness is self-limiting with symptoms lasting for one or two days.

People who have eaten raw oysters harvested from the affected area during the specified dates and have had symptoms of norovirus infection are encouraged to contact their health care professionals and local health departments.

People with weak immune systems, including those affected by AIDS; chronic alcohol abuse; liver, stomach, or blood disorders; cancer; diabetes; or kidney disease and those taking certain medications for rheumatoid arthritis or cancer chemotherapy, should avoid raw oyster consumption altogether, regardless of where the oysters are harvested.