Common source outbreak of salmonellosis in a food factory

Seventy-three employees at a food processing factory employing 2700 staff reported vomiting, diarrhoea, or abdominal pain between 30 July and 3 August 1997. Salmonella enteritidis phage type (PT) 4 was isolated from 47 symptomatic cases and five asymptomatic canteen staff. The epidemic curve suggested a point exposure to a common source: 60% of cases reported illness on 31 July. An uncooked dessert containing raw shell eggs was identified as a possible vehicle of infection. Caterers are reminded that pasteurised egg should be substituted for shell egg in dishes that are eaten raw or only lightly cooked.