Several cases of foodborne illness from local fish, suspected to be caused by the ciguatera toxin, are under investigation through the Department of Fisheries.

For Richalene Knights and her family, early symptoms mimicked food poisoning — then intensified to a burning under the skin, accompanied by an intense bitter taste in their mouths.

“It’s no joke — your hands and feet feel like they’re on fire, and at night you start itching,” said Ms Knights, whose parents and sister also fell ill.

“My parents are in their 70s. To see my mother get so sick was awful. I’m not trying to point the finger of blame at anyone, I just spoke out to make people be careful.”

Ciguatera, known in islands to Bermuda’s south, is a rarity in local waters, where the tiny organisms that carry the toxin have not been present in high enough numbers to cause the illness.

Poisons from the reef plankton accumulate in the meat of grazing fish, and are then concentrated in the larger species that feed on them.

The undetectable toxin is not broken down by cooking, causing rapid sickness in unsuspecting diners.

Early symptoms, which hit Ms Knights’ family within six hours, include vomiting and diarrhoea. Ciguatera leads to headaches, muscle pain and a burning, tingling sensation on contact with anything cold.

“There’s nothing you can do about it, just go through the process,” said Ms Knights, who found her hands stinging when she washed them, followed by a metallic taste in her mouth “as if I had been drinking brine”.

The family had purchased bonito from a Southampton fisherman on November 19, and consumed the fish separately over the next few days. They traced it back to the same meal, which she said had tasted “nice and fresh”, after noticing that all of them were experiencing leg pain.

“By Friday last week it felt like a bad case of the flu, with my legs and arms hurting and itching,” Ms Knights said.

When contacted, the fisherman informed them that he had been speaking with the Department of Fisheries after another customer attended the hospital with a suspected case of ciguatera.

Ms Knights said she had confirmed that the department was testing fish samples. A positive result would buck a long trend for Bermuda, which has the same reef fish such as barracuda that are known elsewhere for carrying ciguatera — but has seldom seen actual cases of the sickness. In rare cases, ciguatera’s neurological symptoms can persist over weeks or even months. For the Knights family, the worst seems to have passed.

“I have an appointment for Wednesday with my doctor,” Ms Knights said. “I didn’t feel deathly sick, once I got over the vomiting. We’ve just been waiting it out, drinking Gatorade and flushing it out of our systems. I just want people to be aware of the symptoms, so they’ll know.”