UC San Diego

Background

Our study aims were to assess hepatitis A virus (HAV) and hepatitis B virus (HBV) susceptibility and infection among young persons who inject drugs (PWID) who may have been vaccinated as children and to evaluate self-report of HAV and HBV vaccination.

Methods

We recruited PWID aged 18-40 years-old in San Diego during 2009 and 2010 and collected demographic, socioeconomic, health, and behavioral factors. Participants were asked if they had been vaccinated against HAV and HBV, and serum samples were collected for HAV and HBV serologic testing.

Results

Of 519 participants, 365 (72%) were male, 252 (49%) were white non-Hispanic, 38 (7%) were Black non-Hispanic, 138 (27%) were White Hispanic, and 22 (4%) were born outside the U. S. Of the total participants, 245 (47%) had surface hepatitis B antibody (anti-HBs) titers <10mIU/ml (i.e., HBV susceptible) and 325 (63%) had no detectable HAV antibodies (HAV susceptible). Hepatitis B surface antigen was detected in 7 (1%) of total participants; and 135 (26%) were anti-HCV-antibody positive. Compared to serologic findings, self-report of HBV and HAV vaccination was 71% and 41% sensitive, and 58% and 73% specific, respectively.

Conclusion

HAV and HBV antibodies in half or more of this young PWID population did not have levels indicative of protection, and about a quarter had HCV infection, putting them at risk for complications resulting from co-infection with HAV or HBV. Programs serving this population should vaccinate PWIDs against HAV and HBV and not rely on self-report of vaccination.