Dozens of people across the country have fallen ill after eating sushi containing raw tuna, the Associated Press reports. Authorities are investigating the cause of a salmonella outbreak affecting nine different states.

The states affected are California, Arizona, Illinois, Mississippi, New Mexico, South Dakota, Virginia, Washington, and Wisconsin. Fifty-three people have been sickened and 10 people are hospitalized, but nobody has died from the condition. The outbreak occurred between March 5 and May 1.

Though most people who have been sickened reported eating raw tuna, the connection hasn't definitively been proven yet. The Los Angeles Times reports that officials are working to find restaurants and distributors linked ot the outbreak.

The FDA recommends that pregnant women, children, older adults, and people with compromised immune systems avoid eating raw fish. And in general, officials recommend you cook your fish thoroughly before eating it.