On August 22, 2000, Marion County Health investigators contacted the Oregon Health Department to report that a number of County residents were suffering from E. coli O157:H7. Three days later Wendy’s International, Inc voluntarily closed its Salem restaurant. The findings by the Marion Health Department made the link to this Wendy’s restaurant clear:
The matched case-control study implicated Wendy’s Restaurant at 2375 Commercial Street SE in Salem as the source of this outbreak of E. coli O157:H7 infection. Molecular sub-typing linked the first nine cases to eight additional cases, including one whose only exposure to Wendy’s was a [Wendy’s] restaurant in Tualatin, Oregon.
Importantly, “[n]o cases of infection caused by this strain of E. coli O157 with illness onset after August 25, 2000, have been detected in Oregon or elsewhere.”
The health department’s final report, attached hereto as Exhibit 1, defined the outbreak victims as follows:
Confirmed case: a person with laboratory-confirmed E. coli O157 infection with onset after eating at Wendy’s Restaurant on SE Commercial Street in Salem (Oregon) since August 7, 2000, or with e. coli O157 infection of the same molecular subtype confirmed by PFGE after eating at any other Wendy’s Restaurant since August 7, 2000;
Presumptive case: a person who developed bloody diarrhea within 7 days of eating at Wendy’s Restaurant on SE Commercial Street in Salem between August 14 and 18, 2000 (the exposure dates of confirmed cases);
Suspect case: a person who developed non-bloody diarrhea within 7 days of eating at Wendy’s Restaurant on SE Commercial Street in Salem between August 14 and 18, 2000 (the exposure dates of confirmed cases);
Secondary case: a person with bloody diarrhea or laboratory-confirmed E. coli O157 infection who did not eat at a Wendy’s Restaurant during the week before onset of diarrhea, but who developed this illness within 7 days of the onset of laboratory-confirmed or presumptive E. coli O157 infection in a household member who ate at Wendy’s Restaurant on SE Commercial Street in Salem between August 14 and 18, 2000, or a household member of a case with E. coli O157 infection of the same molecular subtype confirmed by pulsed field gel electrophoresis after eating at any other Wendy’s Restaurant between August 14 and 18, 2000.
The health department investigation revealed that cross contamination from contaminated ground beef was the outbreak source. The role of cross-contamination as the source of other major E. coli outbreaks has been well documented. Independent events of cross-contamination from beef within the restaurant kitchens, where meats and multiple salad bar items were prepared, were the most likely cause of four separate chain-restaurant associated outbreaks in Washington and Oregon in August, 1993. See Lisa A. Jackson, M.D., et al., “Where’s the Beef?” Archives of Internal Medicine, Volume 160, August 14/28 2000, 2380-2385.
Marion County Inspectors found several food-handling problems that likely resulted in cross-contamination, causing E. coli bacteria in the meat to contaminate other foods. These included:
Food-preparation staff soaked lettuce in the first compartment of a three-compartment sink that was used to rinse bloody-meat-juice-covered pans in which raw hamburger patties had been held, without cleaning and sanitizing the sink between uses.
Food-preparation staff used a cleaning and sanitizing “wet towel, dry towel” process, whereby a shelf above the grill that held raw hamburger patties was wiped clean first with a dry towel, then with a sanitized-soaked wet towel. The dry, bloody-meat-juice-soaked towel was used for hand wiping in both the grill area and the sandwich assembly area (where raw products are placed on cooked burgers).
Poor hand washing was observed.
Prior to reopening, the restaurant was required to do the following:
1. Hand wash Sink/Produce sink in Prep area to be switched to improve accessibility at back prep area hand washing.
2. A new hand wash sink will be provided in the grill/sandwich prep area.
3. All open foods/not sealed will be removed from the facility and replaced with new product.
4. A new utensil washing system will be installed.
5. A barrier will be provided to separate the grill from the sandwich assembling area.
6. In the near future, food preparation sink will be installed at the baked potato station.
7. Prior to reopening, training and re-orientation will be provided to all staff over food preparation procedures. Initially at the Commercial St. Store and then all other Marion County Facilities.
8. Increased monitoring of cooking hot/cold holding, sanitizer rotation and towel rotation.