Multiple outbreaks of Salmonella Typhimurium infections occurred during September and October, 1984, in The Dalles, Oregon. Most of the illnesses were linked to eating at ten different restaurants, particularly from salad bars at these restaurants.

The implicated food items in the salad bars differed from one restaurant to another. No water supply, food item, supplier, or distributor was common to all affected restaurants. There was no evidence that employees were exposed to any common source. In some instances, infected employees may have contributed to the spread of illness by inadvertently contaminating foods, but there was no actual evidence of this. Errors in food rotation and inadequate refrigeration may have facilitated growth of the Salmonella Typhimurium, but could not have initiated the outbreak. A subsequent criminal investigation revealed that members of a religious commune had deliberately contaminated the salad bars in order to affect an upcoming election. Salmonella Typhimurium was found in a laboratory at the commune; it was a genetic match to the Salmonella Typhimurium that had been isolated from the stool of the cases.