The CDC, along with FDA and state and local officials, are investigating a multistate outbreak of Salmonella Muenchen illnesses linked to alfalfa sprouts produced by a Kansas company.

According to CDC, 13 people have been infected by the outbreak in four states—Kansas, Missouri, Oklahoma and Pennsylvania—with five people needing hospitalization. The reported illness onset dates range from Dec. 1, 2015 through Jan. 21.

A collaborative investigation indicated that sprouts produced by Sweetwater Farms LLC are the likely source of this outbreak. Irrigation water and alfalfa sprout samples collected by the FDA from Sweetwater Farms LLC tested positive for Salmonella. Testing to identify the specific strain of Salmonella is ongoing.