On Sunday, May 22, 2005, the Department of Health and Environmental Control (DHEC) was alerted to a possible outbreak of foodborne illness centered at Old South restaurant in Camden, South Carolina. See Final Report, as Attachment No. 1. DHEC officials commenced their investigation the same afternoon. The outbreak they would soon confirm turned out to be one of the biggest in South Carolina history, sickening over 300 people and killing one man.
The environmental investigation commenced the same afternoon with an inspection of the restaurant. The facility had closed for the day, and food from the previous week had already been discarded. Officials returned on May 23 after receiving reports of illness from a family who had received catered food from the previous Thursday’s menu. This time, environmental staff collected surface swabs and questioned staff and owners about food preparation. Officials returned again on May 24, and on this date collected samples of raw turkey and eggs from the lot that had been used in meals on May 19 and 22. The turkey samples were taken for testing to the Food Safety and Inspection Service laboratory in Athens.
Meanwhile, DHEC officials had also begun their epidemiological investigation. Information, including reports of illness, suggested an outbreak at Old South between and including May 18 and May 22. Officials developed the following case definition:
A case is an individual with onset of diarrhea with or without fever, vomiting, abdominal cramps, or nausea OR with at least 3 of 4 non-diarrheal symptoms with onset of symptoms after May 18 and who ate at [Old South] between Thursday, May 18 and Sunday, May 22.
For their case-control study, DHEC officials initially analyzed only people who had dined at Old South on May 19. This analysis revealed that roast turkey was significantly associated with illness, thus prompting second and third studies involving diners from both May 19 and May 22. Ultimately, the combined results of all studies implicated roasted turkey and biscuits as the likely foods that caused illness.
Laboratory results from the environmental investigation further implicated the roast turkey. The raw turkey samples that had been taken for testing at the FSIS laboratory returned positive for Salmonella enteritidis. The Final Report states:
The laboratory results documented the presence of Salmonella enteritidis in the roasted turkey sample collected from the catered event. All the isolates of Salmonella [including stool samples from “cases”] were indistinguishable by PFGE testing using both the Xba I enzyme and the Bln I enzyme. The phage typing of nine isolates from the outbreak by the CDC also identified all of them to be identical.
The final circumstances implicating the turkey were discovered by Old South employees during the course of the investigation. The convection oven that employees had used to cook the contaminated turkey had malfunctioned, thus preventing the turkey from reaching a temperature sufficient to kill Salmonella. More specifically, two of the oven’s three heating elements were inoperable during the outbreak exposure period, leaving only one element to warm the oven.
Nonetheless, and by design, the green indicator light on the oven’s control panel remained lit, thus preventing Old South employees from learning of the malfunction. This was despite the representation in the oven’s manual that, “when lit,” the light “indicates [that] elements are operating.” With no device to indicate that the oven had malfunctioned, restaurant employees continued to cook the contaminated turkey to an insufficient temperature.
In addition, the oven contained no gauge, display, or device to disclose the oven’s actual temperature, thus creating a variance between the operator-designated temperature and the actual oven temperature. This variance was not disclosed to the operator, thus producing false, misleading, and confusing information regarding the operation and actual internal temperature of the oven.
The confluence of these several circumstances formed one of the largest outbreaks in South Carolina history. A total of 304 confirmed and suspected cases were identified during the course of the investigation, and one man died as a result of his infection. The restaurant remained closed during the investigation, re-opening on June 10, after employees had completed food safety training.