The New England Journal of Medicine today published an article profiling the investigation into the 2009 Peanut Corp. of America Salmonella Typhimurium outbreak.  The outbreak killed 9 and sickened more than 700 people (confirmed cases), requiring 166 people to be hospitalized.  Our clients included the families of Cliff Tousignant and Shirley Almer, both of whom died and were among the 9 dead, among many others.  Some of these folks have since had a chance to participate in the passage of historic food safety legislation. 

The outbreak occurred as a result of some of the more abhorrent food safety violations that we’ve encountered in 20 years litigating Salmonella and E. coli cases.  But back the 2009 PCA Salmonella outbreak, as profiled in the New England Journal of Medicine:

Background

Contaminated food ingredients can affect multiple products, each distributed through various channels and consumed in multiple settings. Beginning in November 2008, we investigated a nationwide outbreak of salmonella infections.

Methods

A case was defined as laboratory-confirmed infection with the outbreak strain of Salmonella Typhimurium occurring between September 1, 2008, and April 20, 2009. We conducted two case–control studies, product “trace-back,” and environmental investigations.

Results

Among 714 case patients identified in 46 states, 166 (23%) were hospitalized and 9 (1%) died. In study 1, illness was associated with eating any peanut butter (matched odds ratio, 2.5; 95% confidence interval [CI], 1.3 to 5.3), peanut butter–containing products (matched odds ratio, 2.2; 95% CI, 1.1 to 4.7), and frozen chicken products (matched odds ratio, 4.6; 95% CI, 1.7 to 14.7). Investigations of focal clusters and single cases associated with nine institutions identified a single institutional brand of peanut butter (here called brand X) distributed to all facilities. In study 2, illness was associated with eating peanut butter outside the home (matched odds ratio, 3.9; 95% CI, 1.6 to 10.0) and two brands of peanut butter crackers (brand A: matched odds ratio, 17.2; 95% CI, 6.9 to 51.5; brand B: matched odds ratio, 3.6; 95% CI, 1.3 to 9.8). Both cracker brands were made from brand X peanut paste. The outbreak strain was isolated from brand X peanut butter, brand A crackers, and 15 other products. A total of 3918 peanut butter–containing products were recalled between January 10 and April 29, 2009.

Conclusions

Contaminated peanut butter and peanut products caused a nationwide salmonellosis outbreak. Ingredient-driven outbreaks are challenging to detect and may lead to widespread contamination of numerous food products.