In October 2015 local and state public health officials in Wyoming investigated an outbreak of gastrointestinal illnesses among inmates and staff at a correctional facility. Seventy-nine cases were detected. No one was hospitalized and no one died.

The majority of persons reported onset of symptoms within 1-3 hours after eating lunch served at the facility cafeteria. Seventy nine cases were identified. The predominant symptoms included nausea, gas/bloating, stomach cramps and diarrhea. Lunch served on October 11, 2015 was the only meal significantly associated with illness. Tortilla chips were the only food item associated with illness in multivariate analysis. Laboratory testing of the chips detected hexanal, a measure of rancidity. Investigators determined that the tortilla chips were the likely source of the outbreak. No enteric pathogens were identified in stool specimens tested by the Wyoming Public Health Laboratory.