HEPATITIS B INFECTION IN HOUSEHOLDS OF CHRONIC CARRIERS OF HEPATITIS B SURFACE ANTIGEN

Abstract

Epidemiologic and serologic data were obtained on 422 household contacts of 157 blood donor candidates in the Baltimore Regional Red Cross Blood Program who were asymptomatic chronic carriers of hepatitis B surface antigen (HBsAg) (index carriers), and on 318 household contacts of 157 blood donors who were negative for serologic markers of hepatitis B virus (index controls). Index carriers were matched to index controls and their household contacts were similar with respect to race, sex, and education level completed. HBsAg prevalence was 6.8 times higher, and antibody to HBsAg (anti-HBs) prevalence 2.7 times higher among the contacts of carriers. The combined prevalence for au hepatitis B virus markers was 29.9% among the contacts of carriers compared to 8.8% among the contacts of controls (p < 0.001). Being non-white, the sibling of a carrier, of older age, of lower educational status, and a member of a small household were significantly associated with either a higher antibody or combined hepatitis B prevalence rate. The contacts of female carriers had an HBsAg prevalence rate 4.7 times greater than the contacts of male carriers. Children who had a mother as their index carrier had an eleven fold higher HBsAg prevalence than did children who had a father as their index carrier (18.0% vs. 1.6%, p <0.005). Epidemiologic characteristics of the contacts or their Index carriers, such as the sharing of Items belonging to the index carrier, the type and frequency of sexual relations, and the frequency of potential exposure to body fluids of the index carriers were examined. Contacts of carriers who had had skin lesions in the past year had a higher prevalence of serologic markers for hepatitis B than contacts of carriers without such lesions. No sex-related factors among spouses were significantly associated with an increased prevalence of serologic markers. These data give further support to the concept that person-to-person modes of transmission are important in the spread of hepatitis B within households. The patterns of hepatitis B serologic markers observed here suggest that mother to child transmission is most important in accounting for the high HBsAg prevalence among the contacts; other presently unidentified but close types of contact best explain the patterns of antibody prevalence.