In October 2015 dozens of teachers and staff at Roosevelt High School in Des Moines, Iowa were ill with Clostridium perfringens following a taco meal served at a catered luncheon. The bacteria were found in taco meat and in stool samples collected from ill attendees. School officials purchased the cooked taco meat from a Hy-Vee store located in Windsor Heights. School officials said the meat was left out on a table in a warming tray for an hour before it was served. The Polk County Health Department could not determine if food handling errors at the store or school's food handling were responsible for the outbreak.