The final report on the Salmonella outbreak last year associated with C.F. Prime Chophouse and Wine Bar and Pints & Quarts Pub and Grill in Muskegon County, Michigan has been released. Public Health-Muskegon County (PHMC) has been investigating the outbreak, which sickened 29 customers and employees of the restaurants.
The outbreak was discovered on November 7, 2013, when PHMC received notification of a positive case of Salmonella Enteritidis from the North Ottawa Community Hospital in Grand Haven, Michigan. The next day, six more people were diagnosed; all of those people had eaten at those restaurants in a four-day period from October 30 to November 2, 2013 before they became ill.
There were 16 Salmonella cases in 2011 and 7 cases total in 2012, so this number of people sick in a short period of time was indicative of an outbreak. An epidemiological investigation was launched, with a Case-Control Study to discover an association between illness and any particular food item.
Fifty-eight people participated in the study, along with 35 employees. Questionnaires were developed for the project, and interviews conducted. Six onsite investigations at the restaurants were conducted. Chicken and a Béarnaise sauce, which is made with raw egg yolk, were pinpointed as possible sources of the bacteria. Lettuce was a possible contender.
The outbreak totals were 29 customer confirmed cases, 25 customer probable cases, 2 restaurant staff confirmed cases, and 6 restaurant staff probable cases. Median age ranged from 9 months old to 80 years. Two-thirds of the cases were female. Most of the cases ate at the Pints & Quarts Pub.
Investigation at the restaurants found areas of good practice, including holding coolers ta the proper temperature, raw meat and eggs stored away from ready to eat items, proper final cook temperature of chicken, and clean and well maintained equipment. But there is an inadequate employee health police, no SOP for cross-contamination prevention, and no standard procedure for hot/cold holding. In addition, raw unpasteurized eggs were used in two of the salad dressings as well as the Béarnaise sauce, and hand sinks were used for more than hand washing.
The report concluded that the two restaurants were the source of the outbreak. Food items significantly associated with the Salmonella outbreak were salads, Thai chicken lettuce wraps, and grilled chicken added to the salad. The foods made with raw eggs were also suspect. No single source or act was specifically identified as the cause of the outbreak.
Recommendations were made to management about areas of improvement that can reduce the risk of another outbreak. Restaurant management believes that already-contaminated raw eggs were to blame. The restaurants are allowed to use raw eggs, as long as the menu notes the risks associated with consumption.
