Trends in chronic hepatitis B prevalence in Australian women by country of birth, 2000 to 2016

Routine antenatal screening for chronic hepatitis B (HBV) in countries with high migrant populations provides an opportunity to monitor trends in HBV prevalence and can inform estimates locally and in countries with limited seroprevalence data. We linked perinatal birth register records with HBV notifications in the largest Australian state, over the period 2000-2016. Among women aged 15-44 years, we estimated age-standardized chronic HBV prevalence overall and by country of birth and also estimated trends in age-standardized HBV prevalence over time using regression modelling. Among 903 831 women, 8001 linked to a chronic HBV infection record (overall age-standardized prevalence 0.76%, 95% CI: 0.74-0.78). Prevalence varied by country of birth with the highest estimates among women born in Sierra Leone (11.13%, 95% CI: 8.29-13.96), Taiwan (8.08%, 95% CI: 6.74%-9.43%), Cambodia (7.47%, 95% CI: 6.50%-8.45%) and Vietnam (7.36%, 95% CI: 6.97%-7.75%); more moderate estimates among women from North Korea (2.76%, 95% CI: 1.99-3.53) and Samoa (2.64%, 95% CI: 1.99%-3.29%); prevalence was 0.18% (95% CI: 0.17-0.19) in Australian-born women. Over 17 years, there were significant reductions in HBV prevalence among all women (from 0.88% in 2000 to 0.57% in 2016; P < .0001). Among women from high prevalence countries, the greatest absolute reductions were observed among those from Taiwan (10.1%, P < .001) followed by Tonga (5.4%, P < .001), whereas no reductions were observed for women born in Vietnam (P = .08), South Korea (P = .41) and Sudan (P = .06). In conclusion, routine antenatal HBV testing can be used to inform HBV prevalence estimates and vaccine programme impact in countries with limited surveillance and high migration to Australia