The state Department of Health announced Monday that there are 14 new cases of salmonella on Oahu and that they have been linked to limu poke, or cubed raw fish served with seaweed.

“The silver lining is we’re catching this one early,” said Dr. Sarah Park, state epidemiologist. “We want to get the word out to protect the public, and hopefully we don’t see more cases.”

The cases involve children and adults who developed the illness from mid- to late October. Four cases required hospitalization.

The department’s preliminary investigation has implicated one Oahu seaweed farm, which was ordered to stop its operations and advise its customers to immediately remove the product from sale.

However, the Health Department has not confirmed that the farm was the source of the precise strain of salmonella in question.

The department acted quickly after several patients reported eating limu poke, and found the same strain of salmonella in all cases, Park said.

“We found that the limu was being sourced from one farm,” she said. “Moving on a hunch, while still looking at other sources of contents, we collected samples” from the farm, which tested positive for salmonella.

“Whether it turns out to be different or the same (strain), it should not have come back positive,” Park said.

The department is still investigating other possible sources.

The seaweed has been distributed to a number of Oahu grocery stores, said Park, who did not disclose the farm’s name. The department ordered all distributors to stop sales beginning last weekend.

Clinicians were notified through a public advisory.

Park said reports often come from a laboratory rather than doctors, which can cause up to a three-week lag.

The scope of the outbreak and the distribution of the product are still being investigated.

The incubation period for salmonella is a half-day to three days, moving a lot quicker than the outbreak of hepatitis A, which has an incubation period of 15 to 50 days.

That hepatitis A outbreak began in June, and the source, raw scallops served at Oahu and Kauai Genki Sushi restaurants, was not identified until Aug. 15. One death has been attributed to that outbreak, which struck 292 people.

Salmonella is a bacteria that can cause illness in humans who come in contact with affected animals or their waste or with contaminated food or water. Diarrhea — sometimes bloody — abdominal pain, fever, nausea and vomiting are among the symptoms.