The Alaska Division of Public Health has released a new report, showing a decrease in paralytic shellfish poisoning in recent years.
The report found that between 1993 and 2021, 132 poisoning cases were reported in Alaska. Five deaths were recorded. Most incidents occurred in the boroughs of Kodiak Island, approximately 20-25%. The next highest was Juneau with 16% to 20%.
According to the Centers for Disease Control and Prevention, Paralytic shellfish poisoning (PSP) is the most common and severe form of shellfish poisoning. PSP is caused by eating shellfish contaminated with saxitoxins. These powerful neurotoxins are produced by various marine planktons.
Symptoms usually appear 30 to 60 minutes after eating poisonous shellfish and include numbness and tingling of the face, lips, tongue, arms and legs. There may be headaches, nausea, vomiting and diarrhea.
Severe cases are associated with ingestion of large doses of toxin and clinical features such as ataxia, dysphagia, mental status changes, flaccid paralysis and respiratory failure. The case fatality rate depends on the availability of modern medical care, including mechanical ventilation. The mortality rate can be particularly high in children.
According to one of the report’s contributors, Katherine Newell, a CDC Epidemic Intelligence Officer who is assigned to the Alaska Division of Public Health, PSP is a reportable disease in Alaska due to of the severity of the disease.
Commercially harvested shellfish are tested for the toxin, which is why cases of PSP almost always occur in self-harvested seafood. Contaminated shellfish also tastes and looks the same as uncontaminated seafood. Cooking or freezing fish has no impact on toxins.
The report suggests that, although unclear, the reasons for the recent decline in reported PSP cases may be linked in part to declining consumption of subsistence shellfish, improved awareness of the community at risk of PSP and reduced reporting of suspected cases of PSP.
“It is important to note that the decline in reported cases is not indicative of a reduced risk of PSP in Alaska,” Newell said. Noting that harmful algal blooms, which create saxitoxins and lead to widespread contamination of shellfish, still form every year in the state.
The full report can be found here.
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