An outbreak of hepatitis A associated with a bakery, New York, 1994: the 1968 "West Branch, Michigan' outbreak repeated.

In a community hepatitis A outbreak in the Rochester, New York area, 64 of 79 (81%) people with anti-hepatitis A IgM-antibodies and onset of symptoms from 9 April-31 May 1994, recalled eating food obtained from a retail buyer's club. Eleven (65%) of 17 households with cases contained club members compared with 7 (21%) of 34 neighbourhood-matched control-households (matched odds ratio 8.5; 95% CI 1.7-41.6). Club employees who ate sugar-glazed baked goods were at fourfold increased risk for hepatitis. The source of infection was an IgM-positive baker who contaminated baked goods while applying sugar glaze. Computer-generated purchase lists implicated 11-12 March and 21-24 March as the most likely dates when contamination occurred. This investigation demonstrates the importance of food workers adhering to established hygiene practices. Computer-generated commercial datasets can be useful in epidemiologic investigations.