Vibrio bacteria have closed three commercial growing areas and caused 30 confirmed illnesses in Washington this summer, according to the state Department of Health. Totten Inlet near Olympia, North Bay and Dabob Bay in north Hood Canal are closed for the rest of the summer due to these bacteria, which are common in warm weather conditions. Once water temperatures begin to cool in October, these growing areas will reopen.
People get vibriosis from eating raw or undercooked oysters that have Vibrio parahaemolyticus bacteria in them. Cooking shellfish until the shells just open is not enough to kill Vibrio bacteria. Shellfish should be cooked to an internal temperature of 145 degrees F for at least 15 seconds. Don’t rinse cooked oysters in seawater, which can re-contaminate them.
Vibriosis symptoms include diarrhea, stomach cramps, nausea, vomiting, headache, fever, and chills. Symptoms usually appear 12-24 hours after eating infected shellfish, and can last two to seven days. Vibriosis can be life-threatening for people with low immunity or chronic liver disease. Also at greater risk are people who take antacids, heart or diabetes medication, or who’ve had antibiotic or cancer treatments recently.
“Shellfish is among our favorite local foods in Washington,” said Jerrod Davis, director of the Office of Shellfish and Water Protection. “Some simple steps can keep you healthy after that wonderful summer barbecue.”
Vibrio is a problem during summer months when warm temperatures and low tides allow bacteria to grow. In addition to Totten Inlet, North Bay and Dabob Bay, other growing areas are closed periodically because of high bacterial levels and also biotoxins such as paralytic shellfish poisoning. Be sure to check for closures.
Put shellfish on ice or refrigerate immediately after you buy or harvest them this summer. Make sure you’re buying from a reputable source that handles shellfish correctly with good cooling practices (refrigeration or ice). More tips for handling, storing, and cooking shellfish can be found in our Recreational Shellfish Harvesting fact sheet.
Vibrio isn’t the only health concern for shellfish lovers — and some can’t be cooked out. People who eat shellfish contaminated with biotoxins can become seriously ill or even die. You cannot tell if a toxin is present by looking at the water or the shellfish. Check before you dig. For information on recreational closures, call our toll-free Shellfish Safety Hotline at 1-800-562-5632 or check our online maps for beach closures.