The protective effect of alcohol on the occurrence of epidemic oyster-borne hepatitis A.

Limited data indicate that drinking alcoholic beverages along with eating food contaminated with Shigella or Salmonella decreases the risk and/or the severity of illness. No such study has been reported following exposure to a viral pathogen. During an oyster-borne outbreak of hepatitis A, we studied the effect of ingestion of alcoholic beverages concomitant with consumption of contaminated oysters. The analysis was restricted to 51 cases and 33 controls who had consumed the implicated raw oysters. After controlling for potential confounders, we found a protective effect for beverages that have an alcohol concentration of greater than or equal to 10% (odds ratio = 0.1, 95% confidence interval = 0.02-0.9), but not for beverages with an alcohol concentration of less than 10% (odds ratio = 0.7, 95% confidence interval = 0.2-2.9).