LINCOLN, Neb. (AP) — A food inspector says most — if not all — the prepackaged salad mix that sickened hundreds of people in Iowa and Nebraska wasn’t grown in either state. Iowa Food and Consumer Safety Bureau chief Steven Mandernach said Wednesday that at least 80 percent of the vegetables were grown and processed outside both states’ jurisdictions. Mandernach says officials haven’t confirmed the origins of 20 percent and may never know because victims can’t always remember what they ate.

Officials have said the salad was infected with a rare parasite that causes a lengthy gastrointestinal illness. Outbreaks have been reported in 15 states, although it’s not clear whether they’re connected. Mandernach says state law prohibits his office from releasing the information unless there’s an immediate threat. Officials believe the threat has passed.