Unusual number of seafood poisoning cases reported this summer

Oct 16, 2019

The Alaska Department of Health recorded an unusually high number of cases this summer of a rare allergy-like condition related to unsafely handled fish.
    The condition is Scombroid Poisoning, and is usually associated with tuna, mackerel and mahi-mahi. But at least four of the seven victims of Scombroid reported eating salmon immediately before onset of symptoms. According to CDC figures, of 1,555 cases over the past 20 years, only 11 have been associated with salmon.
    According to the State Section of Epidemiology, the symptoms of Scombroid Poisoning are similar to — but are not — an allergic reaction. What’s happening, according to the section’s Anna Frick, is a protein in the fish is being converted by bacteria into a histamine, which is also part of the body’s reaction to an allergen. 
    “In this case you eat a bunch of histamine and then your body says, ‘Oh my goodness, histamine,’ and responds accordingly,” Frick said. “So if you're familiar with what histamine does in the body, it has a role in allergic responses and it has a role in activating your immune system, which sometimes is good and on purpose and sometimes is not quite correct.”
    Frick says the bacteria are ever-present in the fish, but only become an issue when fresh seafood is improperly handled. Prevention of Scombroid depends on cooling the fish promptly and keeping it cool until it’s cooked. Once scombrotoxin has developed, it cannot be cleaned, frozen or cooked away.
    “What you need to do to prevent Scombroid poisoning is make sure that after you catch a fish that it stays cold below 40 degrees until such time as you're ready to cook it,” she said. “And then once you cook it, you should be good to go as long as you, you know, don't keep the leftover out for too long.”
    Unfortunately, the state was not able to test leftover samples of the seafood any of the seven victims ate. They mostly suffered dizziness, rash, itching, and nausea, with some also experiencing cramping, flushing, headache and shortness of breath. One reported throat tightness and wheezing.
    “Yeah, Scombroid has a very fast onset time. Because you sort of directly consumed that histamines that communicates with your body that it should be responding,” Frick said.
    The symptoms of Scombroid Poisoning generally last between 12 and 48 hours. One case was reported in late May, two in mid June, and one each on July 21st and 28th and again on August 4th and 11th. Four of the seven were female, and all ranged in age from 33 to 58. Two patients were tourists, the other five residents.
    All of those affected this summer in Alaska recovered without complication.
    The Section of Epidemiology says the reason for the unusually high number of scombroid cases this year is unknown.