Prevalence of hepatitis A virus and hepatitis B virus immunity in patients with polymerase chain reaction-confirmed hepatitis C: implications for vaccination strategy

Abstract

OBJECTIVES: Administration of vaccine for hepatitis A virus (HAV) and hepatitis B virus (HBV) is recommended for patients with chronic hepatitis C (CHC) because of the potential for increased severity of acute hepatitis superimposed on existing liver disease. The aim of this study is to determine the prevalence of antibodies directed against HAV and HBV in patients with CHC, analyze demographic and risk factors associated with this prevalence, and develop a cost-effective vaccination strategy. METHODS: We reviewed records from 1092 CHC patients. Demographics and information regarding risk factors were obtained by history and questionnaire administered to all patients. The costs of vaccination and antibody testing were determined, based on standard laboratory and clinic charges at our institution. HAV and HBV markers were correlated to race, age, and risk factors. RESULTS: Of the total population studied (n = 1092), 72% were African-Americans, 27% white, and 1% others. Of 671 CHC patients tested for anti-HAV IgG, 252 (38%) were positive. Of 743 CHC patients tested for HBV antibodies (anti-hepatitis B core IgG or anti-hepatitis B surface), 494 (67%) were positive. African-Americans are more likely to have antibodies to HAV and HBV (67% and 75%, respectively) compared to whites (27% and 20%). The prevalence of anti-HAV was 76% in patients >60 yr, 34% in the 40- to 60-yr-old age group, and 21% in patients <40 yr. The highest prevalence of HBV antibodies was found in patients between the ages of 40–60 yr. No HCV risk factors were associated with increased HAV risk. In CHC patients with HBV antibodies, however, illicit injection drug use was the predominant risk factor. CONCLUSIONS: The prevalence of anti-HAV in patients with CHC was found to be similar to that of the general population in the United States (33% according to recent Centers for Disease Control data), consistent with the hypothesis that the two infections do not share risk factors. Because the prevalence of HAV immunity is low in CHC patients <40 yr, empiric HAV vaccination is cost effective. If two doses of vaccine are to be given, however, antibody testing of all HCV patients is indicated. In the subset of patients >60 yr of age or who are African-American, where the prevalence of HAV exposure is considerably higher, it would be cost effective to check the antibody ($36.00), before vaccination ($97.00). The prevalence of HBV antibodies, however, is significantly increased in patients with CHC compared with the general population (5.3% per the Centers for Disease Control), likely as a result of exposure to similar parenteral risk factors. HBV antibody testing ($26.00 per test) should, therefore, be undertaken in all CHC patients who are hepatitis B surface antigen negative, as this approach is cost-effective compared to empiric HBV vaccination ($438.00 for a three injection course).