State health officials are asking people who recently harvested or ate any shellfish from the Oregon Coast to complete a survey as part of an investigation of at least 20 illnesses linked to shellfish biotoxins.

On May 28, Oregon Health Authority (OHA) urged people to throw out mussels gathered from beaches between Seal Rock State Park north to the Washington border after cases of paralytic shellfish poisoning (PSP) were reported to the agency. The shellfish were harvested at beaches in Lincoln, Tillamook and Clatsop counties.

Among other symptoms, paralytic shellfish poisoning can paralyze respiratory muscles.

The health authority is now asking people who harvested or ate Oregon shellfish since May 13 to take a short survey to help investigators identify a possible cause of the outbreak and how many people became sick. Responses are secure and confidential, and will help OHA Public Health Division investigators learn more about the sources and size of this outbreak.

Those who already completed an interview with their local public health agency do not need to complete the survey.

Contact Rosalie Trevejo (rosalie.trevejo2@oha.oregon.gov) or June Bancroft (june.e.bancroft@oha.oregon.gov) of OHA’s Public Health Division with any questions or concerns about the survey.

On May 23, the Oregon Department of Fish and Wildlife (ODFW) and the Oregon Department of Agriculture (ODA) closed a stretch of Oregon Coast to mussel harvesting from Seal Rock State Park north to Cape Lookout due to high levels of PSP. The mussel harvest closure was extended from Seal Rock State Park north to the Washington border on May 26.

People who experience any symptoms of paralytic shellfish poisoning (PSP) – numbness of the mouth and lips, nausea, vomiting, diarrhea, weakness, and in severe cases, shortness of breath or irregular heartbeat – should immediately contact a health care provider. They can also get advice by calling the Oregon Poison Center at 800-222-1222.

PSP 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 cockles, as well as some fish and crabs, according to the Centers for Disease Control and Prevention. There is no antidote for PSP – treatment involves supportive care and, if necessary, respiratory support.