An investigation of the potential risk of an HAV outbreak in a prison population following the introduction of cases from a community outbreak.

: Increasing Hepatitis A (HAV) infection has been reported in communities in which there is a high level of intravenous drug use. Several cases were identified in a local prison and since the risk of transmission within the prison was felt to be high, it was decided to determine the prevalence of HAV antibodies in the prison population and therefore the number of susceptible inmates. Oral fluid was collected from 269 prisoners for testing for antibodies to HAV. Both IgM and IgG anti-HAV were assessed so that the percentage susceptible and the number recently infected could be ascertained. Eight inmates had evidence of a recent infection. Of the remaining 261, only 56 (21%) were immune to HAV. Therefore vaccination against HAV in addition to HBV should be considered for intravenous drug users and for prisoners remanded from a community where infection is known to be occurring.