A case-control study on risk factors of hepatitis a outbreak

A 1∶2 case-control study was carried out to asses the risk factors of a hepatitis A outbreak. 56 cases of acute hepatitis A and 112 controls were studied. Odds ratios and their 95% confidence limits were computed. The results showed that Jiaban shrimp was the dietary factor of hepatitis A outbreak. The relative risk of eating raw Jiaban shrimps were 19.82 times than that of no eating, and there was a relationship of dosage-reaction in the outbreak. It was concluded that the departments concerned should enhance the sanitary administrating and hepatitis A virus surveil-lance in seafood products.