In general, according to Public Health, raw oysters are most likely to be contaminated in the water before harvesting. Regardless, Environmental Health Investigators conduct onsite visits for each report of illness associated with raw oyster consumption. This helps control risk factors that may be present that could contribute to the spread of norovirus or Vibrio parahaemolyticus. Risk factors for each illness vary, but may include: oysters from unapproved sources, improper refrigeration of oysters (temperatures must be at or below 41 degrees F), handling of raw foods in such a way to minimize the risk of cross-contamination, ill food workers, and/or improper handwashing practices.
Public Health routinely reports the 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. Multiple illnesses tracked to a common growing area may result in the closure of implicated harvest locations or other enforcement actions. For more information, see the DOH Shellfish Program website.
2021 Illnesses Associated with Raw Oysters
| Restaurant/Venue/vendor | Meal date | Number ill | Suspected organism |
| The Crabpot^ 1301 Alaskan Way, Seattle |
6/28/2021 | 1 | Vibrio |
| Crawfish King^ 701 8th Ave S, Seattle |
7/2/2021 | 1 | Vibrio |
| The Crab Pot^ 1301 Alaskan Way, Seattle |
7/2/2021 | 1 | Vibrio |
| Damn the Weather^ 116 1st Ave S, Seattle |
7/3/2021 | 1 | Vibrio |
| Salty’s on Alki^ 1936 Harbor Ave SW, Seattle |
7/4/2021 | 1 | Vibrio |
| Taylor Shellfish^ 1521 Melrose Ave, Seattle |
7/5/2021 | 1 | Vibrio |
| Emmett Watson’s Oyster Bar^ 1916 Pike Pl, Seattle, WA 98101 |
7/5/2021 | 1 | Vibrio |
| Walrus and Carpenter^ 4743 Ballard Ave NW #1b, Seattle |
7/5/2021 | 1 | Vibrio |
| The Crab Pot^ 1301 Alaskan Way, Seattle |
7/7/2021 | 2 | Vibrio |
| White Swan Public House 1001 Fairview Ave N, Seattle |
7/17/2021 | 2 | Vibrio |
* Disclosures posted previously online at: www.kingcounty.gov/outbreak
^ Includes at least one ill person with laboratory-confirmed Vibrio parahaemolyticus
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