Direct milk excretion of Campylobacter jejuni in a dairy cow causing cases of human enteritis

Consumption of milk contaminated with Campylobacter jejuni has been described as a cause of human enteritis. Although faecal contamination of milk with the organism has frequently been described, direct milk excretion of Campylobacter jejuni into milk has rarely been linked with cases of human infection. We describe the investigations undertaken following the isolation of Campylobacter jejuni from samples of unpasteurized milk prior to retail. Results of epidemiological investigations including typing of Campylobacter jejuni isolates using pyrolysis mass spectrometry, Penner and Lior serotyping, biotyping, phage typing and restriction fragment length polymorphism analysis provided convincing evidence implicating direct milk excretion of Campylobacter jejuni by one asymptomatic dairy cow as the source of the milk contamination and the cause of local cases of human enteritis.