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Raw oyster consumption continues, as do vibriosis outbreaks

Since the beginning of June, Public Health Officials have investigated multiple reports of people developing vibriosis symptoms after consuming raw oysters at several restaurants and markets in Seattle-King County area.

There are now 25 confirmed and probable victims who all experienced the watery diarrhea, abdominal cramping and vomiting of vibriosis, as reported by Public Health of Seattle-King County.

“Environmental health inspectors conducted on site investigations to ensure that the oysters were from approved sources, being cold held properly at refrigeration temperatures at or below 41 degrees F and handled in such a way to minimize the risk of cross-contaminations,” according to the update this week from the public health officials.

“The Vibrio bacterium is naturally found in salty, brackish waters where oysters are grown. Therefore, while temperature violations before and after delivery to restaurants can contribute to the growth of Vibrio, the restaurants are not the direct source of Vibrio in oysters.”

Health officials have asked that anyone who has eaten raw oysters in the Seattle area and developed symptoms of vibriosis report the illness to assist with the investigation into the source of the bacteria.

The restaurants implicated thus far, the number of sick customers and the dates they ate at the locations:

Meal date
Salted Sea* 4915 Rainier Ave S, Seattle 7/8/2017 3
Wild Salmon Seafood Market^ 1900 W Nickerson St, Seattle 7/6/2017 4
Salted Sea* 4915 Rainier Ave S, Seattle 7/6/2017 3
Chinooks 1900 W Nickerson St, Seattle 7/6/2017 1
The White Swan Public House* 1001 Fairview Ave N, Seattle 7/3/2017 3
Salted Sea* 4915 Rainier Ave S, Seattle 7/2/2017 2
The White Swan Public House* 1001 Fairview Ave N, Seattle 6/30/2017 3
Costco Wholesale #1225 7725 188th Ave Ne, Redmond 6/25/2017 1
Matt’s Rotisserie & Oyster Lounge^ 7325 166th Ave Ne Ste. F210, Redmond 6/17/2017 1
Salted Sea* 4915 Rainier Ave S, Seattle 6/17/2017 1
Salted Sea*^ 4915 Rainier Ave S, Seattle 6/9/2017 2
Elliott’s Oyster House^ 1201 Alaskan Way Pier 56, Seattle 6/6/2017 1

*Disclosures posted previously online at: www.kingcounty.gov/outbreak
^Includes at least one case with Lab-confirmed Vibrio parahaemolyticus.

Advice to consumers
It’s routine for local public health officials to report vibrio illnesses to the Washington State Department of Health (DOH) Shellfish Program, which is responsible for tracking the harvest locations of the oysters implicated in these illnesses. When multiple illnesses are tracked to a common growing area, enforcement will close the implicated harvest locations. The DOH Shellfish Program website is regularly updated with information on areas closed to harvesting.

Anyone who has eaten raw oysters in the Seattle area recently and developed symptoms of vibriosis should seek medical attention and tell their doctors of the possible exposure to the bacteria so the proper diagnostic tests can be performed.

Symptoms include watery diarrhea, bloody diarrhea, abdominal cramping, nausea, vomiting, headache and fever. People are usually sick for one to seven days, according to the U.S. Centers for Disease Control and Prevention. People usually become sick within 24 hours of eating contaminated seafood.

Annually, vibriosis causes an estimated 80,000 illnesses and 100 deaths in the United States, CDC reports.

Seattle-King County has seen between 20 and 90 confirmed cases of vibriosis reported annually for the past 10 years. The five-year average is 30 cases per year, but higher numbers in recent years spurred action by health officials.

In 2015 there were 32 laboratory-confirmed cases of vibriosis in the state, with 34 cases and 46 cases confirmed in 2014 and 2013, respectively.

To prevent infection by Vibrio bacteria, the Seattle-King County Public Health Department offered these tips:

  • Always cook shellfish and other seafood thoroughly before eating;
  • Wash cutting boards and counters used for shellfish preparation immediately after use to avoid cross contaminating other foods;
  • Wash hands thoroughly with soap after handling raw shellfish;
  • Stay out of brackish or salt water if you have any wounds — including minor scrapes and cuts — or cover wounds with waterproof bandages to prevent a skin infection; and
  • Wash wounds and cuts with soap and water if they have been exposed to seawater, raw seafood or raw seafood juices, to prevent skin infections from Vibrio bacteria.

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