The impact of hepatitis B vaccination in a Western country: recall of vaccination and serological status in Australian adults

Notifications of acute icteric hepatitis B have declined since the introduction of vaccination but it is not clear whether the reservoir of infection and the proportion of adults who remain susceptible have also changed. This has been investigated by evaluation of serological evidence of infection and immunity, patient recall of vaccination and risk factors for exposure to hepatitis B in 2115 adult endoscopy patients in central Sydney. Twenty-one percent were immune, two thirds of these by vaccination. One third of the 440 who recalled "vaccination" were anti-HBs negative. 2.1% of the cohort was HBsAg positive and of these 31% (14/45) were viraemic. Amongst epidemiological risk groups recommended for vaccination, multivariate analysis showed that health care workers (odd ratio, OR = 5.35) and patients diagnosed with hepatitis A (OR = 2.6) or hepatitis C (OR = 2.1) were 5.35, 2.6 and 2.1 times more likely to be immunised, respectively. The great majority of immigrants from high prevalence countries, and of patients reporting other known risks for hepatitis B exposure remain susceptible.