The Ketchikan area accounted for 11 of the 132 — or 14% — of paralytic shellfish poisoning cases confirmed in Alaska between 1993 and 2021, according to an April 21 bulletin released by the state Section of Epidemiology. 
PSP is a neuroparalytic condition that can be fatal, and its symptoms — which include dizziness, tingling, difficulty swallowing, weakness, respiratory failure, ataxia, paralysis, brainstem dysfunction, and a pins and needles sensation — can come on between minutes and hours after ingesting a contaminated shellfish such as clams or mussels, according to the bulletin. Some people affected by PSP require hospitalization or intubation — the bulletin reported five fatalities (with one as recent as 2020) and six intubations during the report's timeframe. 
The poisoning is caused by saxitoxins, which occur during harmful algae blooms, according to the bulletin. 
PSP is particularly common in Alaska, according to the SOE bulletin, which attributes the prevalence of PSP in Alaska to "a combination of factors including a large coastline, abundant shellfish populations, and environmental conditions conducive to HAB formation." 
The majority of PSP cases between 1993 and 2021 were reported from Kodiak (20 cases, 25%), Juneau (16 cases, 20%) and Ketchikan and the Prince of Wales Island area (11 cases each, 14%) although cases were found in all regions of the state. 
The Alaska Department of Health and Social Services last issued a statement confirming a PSP case in Ketchikan in 2015. That announcement stated that the case involved various clams harvested from a north Ketchikan beach in late April of that year, and symptoms were noticed a half hour after eating the clams about four days after collection.
The department also issued warnings about possible cases in Sitka and Juneau in fall 2013 and spring 2012, respectively. 
Online data from the Southeast Alaska Tribal Ocean Research organization showed that an advisory was put in place in October for all shellfish in the area of Ketchikan's Seaport Beach and new samples have not yet been collected. At that time, an advisory also active for Kasaan Harbor on Prince of Wales Island, according to SEATOR information. 
Of the 132 reports of PSP, the average age of the affected individual was 42, although cases affected those ranging in age from 2 to 83, according to the SOE bulletin. Most of the cases involved men. About 53% of those involved were Alaska Native, 26% were Asian and 21% were white.
The majority of cases are reported to have occurred during the spring and summer months, although cases have been reported during every month in Alaska, according to the report. 
The bulletin noted that the PSP-causing biotoxins found in shellfish cannot be cooked, cleaned or frozen out of the shellfish.