The MDL court overseeing the coordinated federal litigation stemming from a 2007 peanut butter recall recently granted summary judgment to the defendant manufacturer ConAgra Foods in multiple cases.  See Southern v. ConAgra Foods Inc., MDL 1845, No. 09-1544  (N.D. Ga. 9/29/10).

Readers may recall that in 2007, ConAgra Foods Inc. recalled jars of Peter Pan and Great Value peanut butter that were made at its Georgia plant, after the CDC and FDA observed a possible association between these products and reports of salmonella poisoning.  As part of the recall, ConAgra instructed consumers to discard the jar but to save the lid, which contained the product code identifying when and where the peanut butter was manufactured.  After the recall, multiple consumers sued ConAgra, alleging they had contracted salmonella after eating either Peter Pan or Great Value peanut butter. The lawsuits were consolidated in an MDL in the Northern District of Georgia.

To prove causation, each plaintiff must show that it is more likely than not that contaminated peanut butter caused his or her illness. The best way to show that peanut butter is contaminated with Salmonella is to test the peanut butter itself, said the court. The fact that the peanut butter was recalled here does not mean that it was contaminated. In fact, most of the recalled peanut butter was completely free of Salmonella contamination. During discovery, accordingly, ConAgra asked the plaintiffs to provide the product code for the peanut butter that allegedly caused their illnesses. It also asked the plaintiffs whether they submitted a blood, urine, or stool sample to a doctor for testing. Because the symptoms of Salmonellosis are similar to those of other common gastrointestinal illnesses, these samples were important in determining causation, said defendant.

Here, the 19 plaintiffs could not establish causation, as a matter of law. First, they could not show that the peanut butter they ate was manufactured by ConAgra at the Sylvester plant during the outbreak.  Plaintiffs did not know the product codes from their peanut butter. Without these numbers, which indicate when the peanut butter was manufactured, it was impossible to know whether the peanut butter was at risk of contamination.

Second, the plaintiffs did not provide enough evidence to show that they contracted Salmonellosis shortly after eating the peanut butter. Symptoms alone are not enough to permit a reliable diagnosis of this disease because the symptoms of Salmonellosis – usually diarrhea, abdominal cramps, and fever – are more commonly associated with viruses, parasites, fungi, other bacteria, toxins, and various chronic diseases. Indeed, the CDC estimates that nearly 300 million cases of diarrhea and related gastrointestinal symptoms occur each year of other causes. A positive blood, urine, or stool sample is the best way to show that Salmonella caused a plaintiff’s illness. A proper differential diagnosis by a physician who examined and treated a plaintiff during his illness may also support a finding of causation in some cases, said the court.

But none of the plaintiffs here provided evidence of a differential diagnosis or a positive blood, urine, or stool culture. None of the plaintiffs’ available medical records indicated that the plaintiffs’ doctors considered and excluded other causes or performed any form of differential diagnosis or diagnostic tests. To the contrary, the records showed that most plaintiffs did not even visit the doctor until several months after eating the allegedly contaminated peanut butter.

Without more, concluded the court, no reasonable jury could find that it was more likely than not that
contaminated peanut butter caused the plaintiffs’ alleged illnesses.