1985 Illinois Milk Contamination Causes Largest Salmonella Outbreak in U.S. History

In 1985, a significant food safety crisis unfolded in Illinois when milk produced at Hillfarm Dairy in Melrose Park became contaminated with Salmonella, leading to one of the largest outbreak of foodborne illness in the United States. This incident resulted in hundreds of thousands of infections across the nation and at least 12 fatalities, marking it as the most severe Salmonella food poisoning outbreak in American history.

The outbreak raised numerous concerns about how contamination could occur in a modern dairy processing environment. Investigations revealed that a malfunctioning valve at the processing plant might have allowed pasteurized milk to mix with raw milk, which can harbor harmful microorganisms such as Salmonella. Laboratory testing of milk samples linked the contaminated lots, with expiration dates up to April 17, 1985, to the outbreak.

Overall, more than 16,100 suspected cases were reported across Illinois and five other Midwest states—Indiana, Iowa, Michigan, Minnesota, and Wisconsin—highlighting the extensive reach of this food safety breach. The contamination was traced back to the screw-on caps of a mixing pipe at Hillfarm Dairy, where Salmonella may have proliferated.

Regulatory actions followed, as the Food and Drug Administration identified 13 violations during an inspection, and legal proceedings ensued against Jewel Companies Inc., which operated the dairy. The company faced lawsuits over water pollution violations and was scrutinized for improper handling of contaminated products.

The political fallout was swift. The Illinois governor at the time dismissed the Public Health Department's director, who was found to be on vacation in Mexico amidst the crisis, and appointed a new health leadership team with medical expertise. The legal case concluded with Jewel officials being cleared of reckless intent, although the outbreak contributed to ongoing debates about food safety oversight.

This tragic episode underscores the importance of vigilant disease surveillance, rigorous safety protocols in food production, and the critical role of public health leadership. Revisiting this episode offers lessons on preventing future outbreaks and ensuring consumer protections in the food industry.

Source: https://medicalxpress.com/news/2025-05-contaminated-illinois-sickened-thousands-salmonella.html