ATLANTA – An ongoing investigation into a Salmonella Heidelberg outbreak related to Foster Farms' chicken products revealed more confirmed cases, the Centers for Disease Control and Prevention reported.

The CDC confirmed a total of 574 individuals were infected with seven outbreak strains of Salmonella Heidelberg in 27 states and Puerto Rico since March 1, 2013. In April, the agency reported 524 confirmed cases in 25 states. CDC said 37 people were hospitalized, but no deaths have been reported.

Livingston, Calif.-based Foster Farms implemented a number of food-safety interventions at three of its California processing plants that were linked to the outbreak. No recall notice was issued in the case, but some stores pulled Foster Farms products from shelves.