The Washington State Department of Health and Snohomish County Health District have identified a confirmed case of paralytic shellfish poisoning (PSP) in a Snohomish County resident. The individual experienced tingling and numbness of the lips, tongue, and extremities after consuming butter clams that were recreationally harvested in Island County.
The butter clams harvested by the ill person had PSP levels over five times the allowable level for harvest. Recreational butter and varnish clam harvesting have been closed for PSP since 2021 in most of Island and Snohomish counties.
PSP can be especially dangerous because:
- Butter and varnish clams are known to retain marine biotoxins and may remain toxic for years.
- Marine biotoxins cannot be reduced or destroyed by cooking, freezing, or cleaning shellfish.
- High levels of marine biotoxins do not always discolor the water.
- Contaminated shellfish do not look or taste different than other shellfish.
PSP symptoms can occur within minutes to a few hours of consuming contaminated shellfish. Death from PSP has occurred in less than 30 minutes. Symptoms can include:
- Tingling and numbness of the lips, tongue, and extremities.
- Nausea, vomiting, and diarrhea.
- Loss of coordination, difficulty speaking, difficulty swallowing, and total muscular paralysis with respiratory arrest (in severe cases).
Anyone who experiences these symptoms should see a health care provider immediately, or call 911 if their symptoms are life-threatening. Prompt medical care can support the person during the temporary paralysis. Suspected PSP and other biotoxin illnesses should be reported to your health care provider and local health jurisdiction.
Butter and varnish clam closure signs are posted at public beaches throughout Island and Snohomish counties. In addition, current biotoxin closures are listed on the Shellfish Safety Map: Washington Shellfish Safety Map. For a recorded list of areas closed for biotoxins, call the biotoxin/red tide hotline at 1-800-562-5632. To learn more about marine biotoxins and marine biotoxin illnesses, visit Marine Biotoxins | Washington State Department of Health