LOS ANGELES (CBSLA.com) — Authorities say 31 Californians have been sickened so far in a multistate outbreak of a strain of Salmonella possibly linked to sushi made from raw tuna.

Public health officials said as of Thursday 53 Salmonella cases have been reported in nine states, 31 of which were in California, according to the California Department of Public Health.

Karen Smith, the director of the CDPH, said in a statement:

“As the investigation continues, this is a good reminder to Californians that there are sometimes risks when eating raw or undercooked meats, fish or poultry.

“This is particularly true for young children, the elderly, or people with compromised immune systems who may be at an increased risk of severe illness.”

Thus far, 10 of the nationwide patients have been hospitalized, but no deaths have been reported.

The CDPH statement said most of the patients reported eating sushi containing raw tuna in the week before falling ill, and the illness dates ranged from March 5 to May 13.

“At this time, the investigation has not conclusively identified a food source,” the U.S. Food and Drug Administration said in a statement, which also indicated that a common brand or supplier of raw tuna hasn’t been identified, either.

Several agencies are investigating the source of the outbreak.

Nine of the California patients live in Los Angeles; six in Orange; four in Riverside; seven in San Diego; one in Santa Barbara; and four in Ventura. The ages of the patients range from under the age of one to 83.

Salmonella infection symptoms include: diarrhea, fever, and abdominal cramps, officials said.

“If there’s a reasonable colony, it will give you vomiting, nausea, diarrhea,” Thomas Horowitz, a family practitioner, said. “It’s very important to get cultures because if we don’t have the cultures, we can’t do the outbreak management, which public health does so well.”