The state has shut down oyster and clam beds off Westport and Norwalk, and issued a voluntary recall of the shellfish harvested there over the last month, warning that those taken from the affected areas could cause illness.

The state Department of Agriculture says the affected shellfish beds -- both recreational and commercial -- are closed indefinitely.

The bacteria Vibrio parahaemolyticus, which has been detected in oysters and clams taken from the affected beds from July 3 through Aug. 2, can cause gastro-intestinal illness. Symptoms, which usually occur 12 to 24 hours after eating infected shellfish, include diarrhea, stomach cramps, nausea, vomiting, head-ache, fever and chills.

Vibrio infections can be life-threatening for immune-compromised people or those with chronic liver disease, officials warn. Also at greater risk are people who regularly take antacids, heart or diabetes medication, and those who have had antibiotic or cancer treatments recently.

Oysters, mussels, hard clams, littleneck clams, chowder clams, quahogs and soft-shell/steamer clams from the affected areas are harvested both commercially and recreationally. A commercial recall is underway, the state agency said.

"We are advising the public not to consume shellfish obtained from the closed recreational and commercial areas, and to discard recalled shellfish to reduce the risk of contaminating other food and food contact surfaces," state Agriculture Commissioner Steven K. Reviczky said in a press release.

"I want to emphasize the importance of heeding this advice. If there is any doubt, throw it out, regardless of how much you love shellfish," he said. "It's just not worth risking the health of you or your loved ones."

Anyone who has bought clams or oysters harvested locally and is concerned that they may be contaminated with the bacteria should contact the store where they were bought for details on where the shellfish were harvested.

Restaurant and store managers who believe they may have acquired infected shellfish should contact their local health departments for more information.

This recall does not include all shellfish commercially harvested from the waters of Norwalk and Westport, but only specific harvest locations. The following harvest locations are included in the recall:

CT 79 Westport, CT 123 Westport, CT 207 Westport, CT 173 Westport, CT 109 Norwalk CT 20 Westport and CT 21 Norwalk.

Also, CT 109 Norwalk, CT 253 Norwalk, CT 268 Westport, CT 254 Westport, CT 599 Westport, CT 255 Norwalk, CT 270 Norwalk, CT 595C Westport and CT 595D Westport.

And CT 105 Westport, CT 207 Westport, CT 67 Westport, CT 171 Westport, CT 71 Westport and CT 73 Norwalk.

All of the preceding locale information may not be on each shellfish tag, and the information may appear in a different order. For example, state officials said, CT 79 Westport may read as "Westport Lot 79, CT," "L-79 Westport," or simply "L-79" with no town designation.

Consumers who think they might have become ill from eating contaminated shellfish should notify their local health departments, as well as consult health-care providers for treatment.

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