Illinois news organizations reported late Friday that health officials are investigating a Salmonella outbreak that may have sickened as many as 50 people in nine counties, most of them since Nov. 1.

The Illinois Department of Public Health was cited as saying many of the people who have become ill reported eating alfalfa sprouts at Jimmy John’s restaurants.

IDPH officials are reportedly scrutinizing alfalfa sprout producers and suppliers and testing produce.

The affected counties are: Adams, Champaign, Cook, Kankakee, McHenry, McLean, Peoria, Will and Winnebago.