In 1984, the community of The Dalles, Oregon experienced a large-scale outbreak of Salmonella Typhimurium. This foodborne disease outbreak, which infected a total of 751 people, was eventually traced back to the salad bar of a local restaurant. However, as investigators continued to pursue this case to further understand the primary food source and gather more information on the pathogen, the investigation continued to turn up with inconsistent information due to the sporadic nature of the outbreak. Following an inconclusive environmental study, a criminal investigation was conducted to find that the Salmonella outbreak was an intentional act of terrorism conducted by the members of the Rajneeshpuram religious association to affect the voter turnout of an upcoming election.
In her case study, Khadija Akther discusses the epidemiological events that made up this case along with the management of the outbreak and communication of information between health officials and the public. The 751 patients were identified through passive surveillance and examination of stool samples for the sample pathogen, which helped investigators categorize the cases into three cohorts: case employees, case customers, and secondary cases. As Akther explains, many different agencies were involved in this case due to the inconsistencies in the identification of the outbreak source. Healthcare workers first reached out to the CDC to aid in the investigation but the case was eventually passed over to law enforcement.
While the Rajneeshpuram organization was identified as the culprit, the overall handling of the case faced many limitations and inefficiencies due to lack of proper management. Akther reports lack of communication and cooperative collaboration amongst the agencies involved leading to disorganization and delays in closing the case.
You can read more about the investigation and it’s implications on the future of foodborne outbreak surveillance in Akther’s case study found here.