FDA warns some oysters and clams from Pacific Northwest could be contaminated with paralytic shellfish toxins

The Food and Drug Administration has issued a warning to avoid shellfish from Oregon and Washington that could be “contaminated with paralytic shellfish toxins.”

The shellfish include oysters and bay clams from Netarts Bay and Tillamook Bay, Oregon, harvested on or after May 28 and all shellfish species from the area of Willapa Bay, Washington, harvested from May 26 to May 30.

The FDA said in a warning last week that the shellfish were distributed to restaurants and food retailers or bought by consumers in Arizona, California, Colorado, Hawaii, Nevada, New York, Oregon and Washington.

Businesses should not serve or sell the shellfish, which should be thrown out. Consumers are warned not to eat them, as “they may be contaminated with the toxins that cause paralytic shellfish poisoning.”

Paralytic shellfish poisoning, or PSP, happens after someone eats shellfish contaminated with saxitoxin, which can cause gastrointestinal distress, neurological symptoms and a sensation of “floating” or disassociation. While most patients recover without treatment, weakness could progress to respiratory paralysis and asphyxiation, according to the National Library of Medicine.

The FDA said shellfish are contaminated with natural toxins from the water where they live, most produced by naturally occurring marine algae.

“Shellfish can retain the toxin for different lengths of time. Some species cleanse themselves of toxins rapidly, whereas others are much slower to remove the toxins. This lengthens the period of time they pose a human health risk from consumption,” the FDA warning said.

Shellfish containing paralytic shellfish toxins can look, smell and taste normal. The toxins can’t be removed by cooking or freezing.

Most people with paralytic shellfish poisoning develop symptoms within 30 minutes of consuming contaminated seafood; symptoms range from the tingling of the lips, the mouth and the tongue and a “pins and needles” sensation to vomiting and respiratory paralysis.

People who experience symptoms should contact their health care providers and report their symptoms to their local health departments, the FDA advised.

The Oregon Agriculture Department had advised the FDA of the recall of certain oysters and bay clams on May 30 “due to elevated PSP levels.” The same day, the Washington Health Department advised the FDA of a recall for all shellfish species harvested from growing areas in Willapa Bay, also because of elevated PSP levels.

“The FDA is awaiting further information on distribution of the shellfish harvested and will continue to monitor the investigation and provide assistance to state authorities as needed. As new information becomes available, the FDA will update the safety alert," the agency said.

This article was originally published on NBCNews.com