1Population Health Sciences, University of Bristol, Bristol, UK.
2National Drug and Alcohol Research Centre, UNSW Sydney, Sydney, Australia.
3National Drug Research Institute, Melbourne, Australia.
4National Centre for Youth Substance Use Research, The University of Queensland, Brisbane, Australia.
5Kirby Institute, UNSW Sydney, Sydney, Australia.
6Department of Family Medicine and Emergency Medicine, University of Montreal, Montreal, Canada.
7Research Centre of the Hospital Centre of the University of Montreal, Montreal, Canada.
Introduction: Globally, hepatitis B virus (HBV) is a leading cause of liver disease. People who inject drugs (PWID) are at greater risk than the general population of contracting HBV. This risk could depend on societal factors in different countries. We investigated the associations between country-level chronic HBV prevalence in PWID with national indicators of development and prevalence of HIV and hepatitis C virus (HCV).
Methods: We used global systematic review data on chronic HBV prevalence (hepatitis B surface antigen-positive) among PWID and country-level sociodemographic characteristics from online databases. National random-effects meta-analysis estimates of HBV prevalence were the outcome in linear regression models testing for associations with country-level characteristics.
Results: The study included 131,710 PWID from 304 estimates in 55 countries: the pooled HBV prevalence among PWID in the countries analysed was 4.5% (95% CI 3.9-5.1), the highest regional pooled prevalence was in East and Southeast Asia (17.6% [13.3-22.3]), and the lowest was in Western Europe (1.7% [1.4-2.1]). In multivariable models, no indicators of development were associated with HBV prevalence, but there was evidence of positive associations between HBV prevalence in the general population and among PWID, and evidence of HIV and HCV prevalence in PWID being associated with HBV prevalence in PWID: multivariable coefficients 0.03 (95% CI 0.01-0.04); p < 0.001, and 0.01 (95% CI 0.00-0.03); p = 0.01, respectively.
Discussion and conclusions: HBV prevalence among PWID was associated with HIV and HCV prevalence among PWID and background HBV prevalence in the general population, highlighting the need for improving harm reduction in PWID and implementation of HBV vaccination, especially where HBV is endemic.