Hepatitis A prevalence among injection drug users.

OBJECTIVE

The purpose of this study was to develop a descriptive model of the association between injection drug use and hepatitis A (HAV) in a sample of injection drug users (IDUs).

DESIGN

From May 1997 to July 1999, 493 subjects were administered the NIDA Risk Behavior Assessment (RBA). Participants had blood drawn; sera were tested for antibodies to HAV, hepatitis B core (HBcAB), and hepatitis C. The principal method of analysis was logistic regression.

SETTING

The study took place in a community-based field station in Anchorage, Alaska.

PARTICIPANTS

Eligibility was determined using the following criteria: a) age greater than 17 years, b) possession of picture identification, c) positive urinalysis for cocaine metabolites, morphine, and/or amphetamines using the ONTRAK system (Roche Diagnostics), and d) injection drug use in the last six months as confirmed by presentation of track marks.

MAIN OUTCOME MEASURE: Presence of antibodies to HAV infection.

RESULTS

The prevalence of total HAV antibody in our sample was 33% (161/493). The final multivariate logistic model, using positive HAV serostatus as the outcome, included positive HBcAB serostatus (OR = 3.43; 95% CI, 2.22-5.30), less than high school education (vs. high school or greater education) (OR = 2.05; 95% CI, 1.33-3.17), age (OR = 1.06 (each year); 95% CI, 1.03-1.09), number of days injected heroin in the last 30 days (OR = 1.05 (each day), 95% CI, 1.01-1.08), and race (White vs. all other race/ethnicities) (OR = 0.49; 95% CI, 0.32-0.75).

CONCLUSIONS

A model including both demographic and drug use variables best describes HAV prevalence in this sample. Findings suggest that IDUs are targets for interventions focusing on hepatitis vaccinations and hygiene practices. Further research is needed to understand the association of HAV with hepatitis B infection.