LOS ANGELES » A salmonella outbreak likely linked to raw tuna has sickened 53 people in nine states, health officials said Thursday.

Most of the cases — 31 — are in California, officials at the California Department of Public Health said. Other affected states include Arizona, Illinois, Mississippi, New Mexico, South Dakota, Virginia, Washington and Wisconsin.

Ten people have been hospitalized but no deaths have been reported, according to state and federal officials. The source of the outbreak is unknown, but most who fell ill reported eating sushi containing raw tuna.

"At this time, a common brand or supplier of raw tuna has not been identified," the Centers for Disease Control and Prevention said on its website.

Salmonella is a bacteria and the most common source of food poisoning in the U.S. Symptoms include diarrhea, cramping and fever.

Health officials said the elderly, young children, pregnant women and people with weak immune systems should not eat raw fish or raw shellfish.

"This is a good reminder to Californians that there are sometimes risks when eating raw or undercooked meats, fish or poultry," Dr. Karen Smith, director of the California Department of Public Health, said in a statement.