Campylobacter infection associated with consumption of duck liver pâté: a retrospective cohort study in the setting of near universal exposure

A retrospective cohort study was performed following several reported cases of gastrointestinal illness after a catered event. The attack rate was 45/77 (58·4%) by clinical case definition, with four individuals confirmed to have Campylobacter . There was near universal exposure to most foodstuffs served; consumption of duck liver pâte [relative risk (RR) 2·53, 95% confidence interval (CI) 1·05–6·10], mixed leaf salad (RR 2·91, 95% CI 1·22–6·92) and table water (RR undefined, P P Campylobacter jejuni and C. coli ; water sampling was negative. Making inferences about causation in the presence of near universal exposures in this study required consideration of the limitations of statistical analysis, with the most compelling evidence of the causal role of inadequately prepared duck liver pâte provided by environmental investigation.