During the investigation of an interstate outbreak of gastroenteritis due to Salmonella newbrunswick, epidemiologic data led to the hypothesis that instant nonfat dry milk was the vehicle of infection. The same serotype was isolated from shelf samples of the product and from a single large milk-drying plant where equipment and processing were conductive to introduction and spread of salmonellae. Subsequent surveys of milk-drying plants in various states resulted in isolation of numerous Salmonella serotypes from dried milk products. Instant nonfat dry milk should be considered to be a possible source of infection in future epidemiologic investigations of cases of human salmonellosis.
Collins RN, Treger MD, Goldsby JB, Boring JR, Coohon DB, Barr RN. Interstate Outbreak of Salmonella newbrunswick Infection Traced to Powdered Milk. JAMA. 1968;203(10):838-844. doi:10.1001/jama.1968.03140100020005