Paralytic Shellfish Poisoning: Here’s What to Know

Oysters at the raw bar at Fiola Mare restaurant on the Georgetown Waterfront in Washington, DC. Credit - Scott Suchman/ Getty Image

The FDA issued a warning last week that shellfish originating from growing areas in Netarts Bay and Tillamook Bay, Oregon, may be contaminated with the toxins that cause paralytic shellfish poisoning, or PSP. The administration is advising consumers to avoid eating oysters and clams from the region, including calling on restaurants and food retailers to dispose of them.

The contamination has been found in oysters and bay clams distributed in Arizona, California, Colorado, Hawaii, Nevada, New York, Oregon and Washington. As of May 30, the FDA had not reported any illnesses or deaths from the poisoning.

Here’s what to know about paralytic shellfish poisoning.

What is PSP?

Paralytic shellfish poisoning originates from paralytic shellfish toxin, a naturally occurring biotoxin that is produced in some species of microscopic algae. When molluscan shellfish, such as clams, mussels, oysters, geoduck, and scallops, consume the toxin in algae, they can accumulate the poison. While some species are able to quickly rid themselves of the toxins, others take longer to cleanse it from their systems. The toxin can be passed on to humans through eating shellfish and crabs, which might also become toxic when they feed on infected shellfish.

What are the symptoms of PSP?

Symptoms of PSP can occur within 30 minutes of consuming contaminated seafood and can range from tingling of the lips, mouth, and tongue, to respiratory paralysis and may include these other symptoms: numbness of arms and legs, “pins and needles” sensation, weakness, loss of muscle coordination, floating feeling, nausea, shortness of breath, dizziness, vomiting, and headache.

The FDA advises that Individuals experiencing symptoms of PSP to contact their healthcare provider and report their symptoms to their local Health Department.

Is PSP life-threatening?

There is no specific treatment for PSP and it can be life threatening to humans. Patients are usually given respiratory support and fluid therapy. If patients survive the first 24 hours, their prognosis is considered good, In fatal cases, death is typically due to asphyxiation.

Can you tell if your food contains Paralytic shellfish toxins (PSTs)?

Food containing PSTs may look, smell, and taste normal. Cooking or freezing shellfish does not remove the toxins. Most nations have certified PSP testing programs. 
However, commercially harvested shellfish come from licensed, certified growers that are required to meet state and federal health standards and undergo regular testing for toxins.

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