ConAgra Foods has recalled its Marie Callender’s Cheesy Chicken & Rice meals, after federal food inspectors reported a possible link between the frozen dish and a 15-state outbreak of salmonella.

Since consumers began reporting illnesses in April and May, the Centers for Disease Control and Prevention, the U.S. Department of Agriculture and the U.S. Food and Drug Administration have been investigating how a rare type of salmonella called Salmonella Chester managed to affect dozens of people in 15 states, coast-to-coast.

The federal probe has not conclusively traced the outbreak to any foods, but eight out of 30 affected by Salmonella Chester also reported eating the Marie Callender’s dinner. No deaths have been reported.

On Friday, the Minnesota Department of Agriculture laboratory told the CDC that it had isolated Salmonella Chester from an unopened package of the frozen food, submitted by a case patient.

Major grocery chains like Giant Food LLC and Stop & Shop Supermarket Co. have also removed their stocks of the Marie Callender’s dish. The CDC has advised consumers to thoroughly follow cooking instructions on frozen dinner labels. Consumers must bake their dinners for as long as they need to be cooked, it said, and should check the food’s internal temperature.