Hawaiian state health investigators have identified a relatively rare type of salmonella poisoning on Oahu that they linked to similar cases on the mainland through "fingerprints" of the bacteria’s DNA.

Dr. Paul Effler, state epidemiologist, said illnesses are believed due to raw ahi imported and distributed to Hawaii and other places, and that in Hawaii, it looks as though people became ill after eating raw ahi mostly in poke but also sashimi. A sushi restaurant was involved in some mainland cases, he said.

Janice Okubo, state Health Department spokeswoman, was cited as saying about 30 cases have been confirmed on Oahu since October, and that five people were hospitalized but have been released, adding, "They have all recovered or are recovering."

The unusual culprit is known as salmonella Paratyphi B. Okubo said usually, only about 10 cases of Paratyphi B occur annually.