Hepatitis D virus infection among intravenous drug abusers in Taiwan: analysis of risk factors and liver function tests.

To investigate the prevalence of hepatitis D virus (HDV) and hepatitis B virus (HBV) infection among intravenous drug abusers in Taiwan, a total of 761 male prisoners, including 680 intravenous drug abusers, were studied for serological markers of HBV and HDV. Questionnaires were distributed to evaluate the risk factors for HDV infection and also to estimate the strength of association among HDV infection and the risk factors. HBV infection was common, and the positive rates of HBV markers between intravenous drug abusers and non-drug abusers were not statistically different. However, the positive rate of the antibody to HDV was significantly higher among intravenous drug abusers than among non-drug abusers (21.3% vs. 8.6%). Of 131 chronic HBV carriers with intravenous drug abuse, 119 (91%) were anti-HD positive. Using multiple logistic regression models, we found that the most important risk factor for HDV infection was hepatitis B surface antigen (HBsAg) carriage, and intravenous drug addiction the next. A matched case-control study also was conducted to compare liver function tests among both anti-HD- and HBsAg-positive group anti-HD-negative, and HBs-AG-positive group as well as those with neither positive. Statistically significant difference in liver function tests was not found. It is concluded that the HBsAg carriers with intravenous drug abuse in Taiwan are commonly HDV infected with and that the infection does not seem to affect the liver as assessed by liver function tests.