Self-reported lifetime Hepatitis B virus testing, and vaccination uptake among people who inject drugs in Iran: a nationwide study in 2020.

Background: Hepatitis B virus (HBV) infection is a silent epidemic among people who inject drugs (PWID). HBV testing and vaccination are important for PWID to reduce the risk of infection, prevent chronic complications and contribute to public health efforts in addressing HBV transmission. Our objective was to assess the self-reported lifetime uptake of HBV testing and vaccination among PWID in Iran and their associated factors.

Method: This cross-sectional study was conducted among 2,684 PWID in 11 large cities from July 2019 to March 2020 using a respondent-driven sampling method. Participants were interviewed face-to-face and asked about their lifetime experience of HBV testing and vaccination uptake as the outcome. Logistic regression models were built to identify related factors for reporting HBV testing and vaccination uptake.

Results: The prevalence of HBV testing and vaccination uptake among PWID was 14.2% (95% confidence intervals [CI]: 12.8-15.6) and 16.4% (95% CI: 14.9-18.1), respectively. Shared needles, syringes, or equipment in the past 12 months decreased the odds of reporting lifetime HBV testing uptake (Adjusted odds ratio [AOR]:0.46, 95% CI: 0.29-0.72). However, having an academic education (AOR: 1.89, 95% CI: 1.09-3.30) and lifetime experience of homelessness (AOR: 1.58, 95% CI: 1.21-2.06) increased the odds of reporting lifetime HBV vaccination uptake.

Conclusion: Our study highlighted the low prevalence of HBV testing and vaccination uptake among PWID in Iran. It is essential to understand and address the obstacles preventing PWID from getting tested and vaccinated for HBV. Addressing these barriers could significantly reduce the burden of HBV among this socio-economically marginalized population.