8th Circuit Resurrects Causation Expert Witnesses in Contaminated Baby Formula Case

Kristin Casler

Written by
— Updated on June 22, 2020

baby formulaCase:

Scott Johnson v. Mead Johnson & Co., Nos. 13–1681, 13–2685, Eighth Circuit U.S. Court of Appeals; June 6, 2014


Scott Johnson, as guardian ad litem for his infant, H.T.P., asserted claims against baby formula maker Mead Johnson & Co. for negligence, products liability and failure to warn after the child sustained severe, permanent brain damage from Cronobacter sakazakii, or C. sak bacterial infection.

The containers of formula taken from the home did not contain any C. sak bacteria; however, one emptied container was not recovered. Mead Johnson twice previously had issued a nationwide recall for C. sak-contaminated baby formula. The home environment was not tested, nor was the specific Mead plant where this Enfamil was manufactured.

Medical Causation / Epidemiology Expert Witnesses:

Plaintiff’s expert witnesses, Drs. Jason, Farmer and Donnelly, concluded that C. sak bacteria in the formula caused the baby’s injuries. The U.S. District Court for the District of Minnesota found the experts’ opinions unreliable because the experts didn’t do adequate differential diagnosis. Specifically, the experts did not adequately rule out other possible sources of C. sak contamination, such as the municipal water supply or the pipes/environment in the Johnson home, the judge said.

Consequently, the District Court granted Mead Johnson’s motion to exclude the plaintiff’s experts and granted summary judgment in the manufacturer’s favor.

Admissibility of Medical Causation / Epidemiology Expert Witnesses:

The Eighth Circuit U.S. Court of Appeals panel held that the District Court abused its discretion in excluding the experts’ testimony.

The District Court violated the liberal admission standards outlined in Federal Rule of Evidence 702 and Daubert v. Merrell Dow Pharmaceuticals, Inc. (509 U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469 [1993]) by resolving doubts in favor of keeping the testimony out and relying upon its own assessment of the correctness of the expert opinions, the panel said.

“By doing so, it disallowed the adversarial process to work,” the panel said.

Of the Rule 702 admissibility factors, only the question of whether the testimony was trustworthy enough to assist the trier of fact was in dispute, the panel said.

Relying on Glastetter v. Novartis Pharmaceuticals Corp. (252 F.3d 986 [8th Cir.2001]) (per curiam), the District Court found the experts’ differential etiology methodology lacking. The appeals panel differentiated Glastetter because the expert there had no proof that the drug at issue caused the resulting medical condition. In this case however, no one disputes that Enfamil can be and has been a source of C. sak.

Regarding the experts’ ruling out of other possible sources of the bacteria, the appeals panel said it has consistently ruled that experts are not required to rule out all possible causes when performing the differential etiology analysis.

“So even if the district court believed there were better grounds for some alternative conclusion (perhaps that the microwave killed any C. sak), or there were some flaws in the experts’ methods (for not having tested the household environment or that water testing was incomplete), because the expert testimony in this case was within ‘the range where experts might reasonably differ,’ the jury, not the trial court, should be the one to ‘decide among the conflicting views of different experts,’” the panel ruled.

The panel found Johnson’s experts’ methodology was scientifically valid, could properly be applied to the facts of this case, and, therefore, was reliable enough to assist the trier of fact. It reversed summary judgment for Mead Johnson.



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