PREVALENCE AND DETERMINANTS OF HEPATITIS-A VIRUS EXPOSURE AMONG PRISON ENTRANTS IN QUEENSLAND, AUSTRALIA - IMPLICATIONS FOR PUBLIC-HEALTH CONTROL

In September 1997, a multicentre outbreak of hepatitis A virus (HAV) i nfection occurred in the Queensland prison system following a prolonge d community-based HAV epidemic among illicit drug users. As part of th e public health response, a cross-sectional survey was undertaken to e stimate the seroprevalence of, and identify the determinants for, rece nt and past HAV infection among the incoming male prisoner population, Exposure data were collected through face-to-face interviews with 214 consenting inmates, whose sera were screened for immunoglobulin G (Ig G) and immunoglobulin M (IgM) antibodies to HAV. Overall, 81 (37.9%) i nmates were HAV-IgG seropositive, and four inmates were HAV-IgM seropo sitive, HAV-IgG seropositivity was strongly associated with year of bi rth (age) (P-trend<0.0001), being born outside Australia (relative ris k (RR) 1.9, 95% CI 1.4-2.7) and being of a non-English speaking backgr ound (RR 2.5, 95% CI 1.7-3.7). Lifestyle exposures (such as occupation , overseas travel and illict drug use) were not associated with an inc reased risk of HAV-IgG seropositivity. In contrast, all four HAV-IgM s eropositive inmates were English-speaking, Australian-born males who u sed illicit drugs, These findings suggest that the risk factors for re cent and past HAV infections among prisoners differ, with implications for HAV control in correctional settings. Strategies for HAV preventi on, including routine screening of inmates and vaccination of suscepti bles, are considered in the context of current models of disease trans mission.