An individual in Clam Gulch may have suffered paralytic shellfish poisoning from clams the person harvested Sunday, the Alaska Department of Health and Social Services said Tuesday.

The case was not reported until Monday. The person became ill about four hours after eating razor clams Sunday evening, DHSS spokesperson Greg Wilkinson said. This is the first probable case of paralytic shellfish poisoning on the Kenai Peninsula this year, he said.

State epidemiologist Louisa Castrodale said symptoms of PSP vary, but typically start with numbness around the mouth and tongue and difficulty breathing.

Wilkinson said if the toxin is strong enough it can stop the lungs from working and cause death. He said there is no treatment for PSP; victims must wait for it to pass. In extreme cases a respirator and oxygen masks are used.

This case involved razor clams and possibly butter clams that were dug about 1.5 miles down the beach near the big tower in Clam Gulch, according to a DHSS press release.

The person did not seek medical care and no food was left over to test for toxins, Castrodale said. The toxin did pass through the individual’s system. The individual has since recovered, she said.

Incidence of toxic shellfish depends on how much algae blooms contaminate the clams, Castrodale said. According to a Division of Environmental Health fact sheet, clams and mussels absorb and expunge PST at different rates and retain the toxins for different lengths of time. One beach can have safe or no levels of the toxin, and another beach might have levels high enough to make someone sick.

“It is tricky. There are no obvious skull and crossbones on the clams,” Castrodale said.

All locally harvested shellfish — including clams, mussels, oysters, geoducks and scallops — can contain PSP, which cannot be cooked, cleaned or frozen out of shellfish, according to the release.

Shellfish from restaurants and stores must be purchased from certified growers that are required to have their products regularly tested, according to a DEC fact sheet.

Wilkinson said DHSS is asking recreational clam diggers to be careful when harvesting and to seek immediate care if they exhibit any symptoms. He said doctors are required to report PSP to the state.

The Kachemak Bay Research Reserve tests razor clams, butter clams and mussels on south Kenai Peninsula beaches and plans to dig clams in Clam Gulch to test for toxins, Castrodale said. Results should take about a week.

The toxins can cause death in as little as two hours, according to the release.

“Our position is (clams are) just not safe,” Wilkinson said.

Paralytic shellfish poisoning is considered a public health emergency. Suspected cases must be reported immediately to the Section of Epidemiology by health care providers at 907-269-8000 during work hours or 800-478-0084 after hours.

Reach Dan Balmer at daniel.balmer@peninsulaclarion.com.