Outbreak of paralytic shellfish poisoning reported involving Oregon mussels

An outbreak of crippling shellfish poisoning that has sickened at least two dozen people has prompted health officials to urge those who have harvested mussels in a part of the Oregon coast since Saturday to throw away the mollusks.

Officials with the Oregon Health Authority’s Public Health Division also recommend that people experiencing symptoms of paralytic shellfish poisoning include numbness of the mouth and lips, nausea, vomiting, diarrhea, weakness and, in severe cases, shortness of breath or irregular heartbeat. to contact a healthcare provider immediately. Advice is also available by calling the Oregon Poison Center at 800-222-1222.

All 20 people who became ill reported recreationally harvesting mussels on May 25 or 26 at Short Beach near Oceanside in Tillamook County, and Hug Point and near Seaside in Clatsop County. Some cases have been hospitalized, but no deaths have been reported.

On May 23, the Oregon Department of Fish and Wildlife and the Oregon Department of Agriculture closed a stretch of the Oregon coast to mussel harvesting from Seal Rock State Park north to Cape Lookout due to high levels of paralytic shellfish poisoning. On Sunday, the mussel harvest closure was extended from Seal Rock State Park north to the Washington border.

“We have two messages: If you have been collecting mussels since Saturday from beaches in the coastal area that ODFW and ODA have closed for harvest – and are preparing them for a meal or storing them in the freezer for a later time – please throw them away gone now. and do not feed them to pets,” said Emilio DeBess, epidemiologist with the Oregon Public Health Division’s Acute and Communicable Disease Prevention Branch. “And if you eat any of these mussels and feel sick, see a doctor immediately.”

DeBess said the recommendations apply only to mussels harvested by private individuals, and not to mussels harvested commercially and purchased at a grocery store or restaurant.

Paralytic shellfish poisoning is a foodborne illness caused by saxitoxins produced by marine algae and caused by eating shellfish contaminated with the naturally occurring biotoxin, including scallops, mussels, clams, oysters and clams, as well as some fish and crabs , according to the Center for Disease Control and Prevention. There is no antidote for the poisoning. Treatment includes supportive care and, if necessary, respiratory support.

Paralytic shellfish poisoning is the most common and most serious form of shellfish poisoning. It occurs worldwide, but is most common in temperate waters off the Atlantic and Pacific coasts of North America.

Signs of illness usually appear 30 to 60 minutes after a person eats poisonous shellfish and include numbness and tingling in the face, lips, tongue, arms and legs. Patients may also have diarrhea and vomiting, headache and nausea. Severe cases involve ingestion of large doses of toxin and clinical features such as poor muscle control, clumsiness or slurred speech, difficulty swallowing, loose or floppy limbs, changes in mental status, and respiratory failure.

Shellfish paralysis can be fatal, especially for children. Appropriate medical care can reduce the risk of death.

Shellfish poisoning can be prevented by avoiding potentially contaminated shellfish, which is especially important in areas during or shortly after algae blooms. Seashell toxins cannot be destroyed by cooking or freezing, and the shellfish containing these substances do not necessarily taste different from uncontaminated shellfish.

Avoid harvesting and consuming seafood from beaches with biotoxin closures.

The treatment of paralytic shellfish poisoning is symptomatic and supportive. In severe cases of paralytic shellfish poisoning, mechanical ventilation may be necessary.