Minnesota is one of 42 states with confirmed cases of salmonella. The Minnesota Department of Health says 30 people have been sickened by the bacteria since early November. Eleven of those were hospitalized.
One person died, but officials don't know if salmonella poisoning caused the death because the person was already quite ill with other health conditions.
Spokesman Doug Schultz says the Health Department is working with the U.S. Centers for Disease Control and Prevention to determine the cause of the outbreak. He says there are no strong leads yet.
"It would be highly unlikely that all of these cases would by person-to-person transmission. It's more than likely going to be some type of a food source that was distributed widely. But it's hard to say what that might be," said Schultz.
The Health Department is also working closely with a group of student investigators from the University of Minnesota called "Team Diarrhea" to determine the cause of the outbreak.
The agency says it is possible that more salmonella cases will be reported in the days and weeks ahead.
Nationwide, nearly 400 people have been sickened by the bacteria.
Health officials in Georgia said Thursday they've identified cases in five people who became ill from mid-October to mid-December. No one died, but at least one person was hospitalized.
In Ohio, 51 people in 20 counties had the same type of salmonella, which happened about the same time as the Georgia cases, health officials said. At least a dozen were hospitalized.
California officials say they had 51 cases as of last week.
Most people infected with salmonella develop diarrhea, fever and abdominal cramps 12 to 72 hours after infection. The illness usually lasts four to seven days, and most people recover without treatment.
Officials say steps to protect against the illness include careful handling and preparation of raw meat, and frequent hand washing.
CDC officials say the cases in the outbreak have all been genetically fingerprinted as the Typhimurium type, which is among the most common forms of salmonella food poisoning.
(The Associated Press contributed to this report)