Risk factors for intrafamilial spread of hepatitis B in northeastern Bosnia and Herzegovina

BACKGROUND: Accurate estimations of hepatitis B virus transmission risk for any region in Bosnia and Herzegovina are not clearly established. We aimed to determine levels of risk associated with intrafamilial transmission of hepatitis B infection within families in our region. PATIENTS AND METHODS: Family members of 81 chronic carriers of hepatitis B surface antigen (>6 months positive and considered as index case) were tested for hepatitis B markers. For family members, we recorded their age, sex, and family relationship to the index case, and vaccination status. RESULTS: The proportion of HBsAg positive family members was 25/207 (12.1%), while the proportion of family members with evidence of exposure to HBV was 80/207 (38.6%). Only 17/207 (8.2%) family members had evidence of past HBV vaccination. Age was found to be a significant predictor of HBV exposure of family members (odds ratio 1.05, 95% CI 1.03-1.07, P<.001). In a multivariate analysis, HBsAg positivity was associated with a female index case (odds ratio 11.31, 95% CI 3.73-34.32, P<.001), HBeAg positivity in the index case (odds ratio 5.56, 95% CI 1.80-17.23, P<.005) and being a mother of the index case (odds ratio 9.82, 95% CI 2.43-39.68, P<.005). A female index case (odds ratio 4.87, 95% CI 2.21-10.72, P<.001), HBeAg positivity in the index case (odds ratio 3.22, 95% CI 1.15-9.00, P<.05) and being a mother of the index case (odds ratio 3.72, 95% CI 1.19-11.64, P<.05) were also risk factors for HBV exposure among family members. The combination of HBeAg positivity and female index case was a significant predictor for HBsAg positivity of family members (odds ratio 70.39, 95% CI 8.20-604.61, P<.001). CONCLUSIONS: Children of HBeAg positive mothers are at highest risk for becoming chronic carriers themselves and generally, the combination of female sex and HBeAg positivity dramatically increases the chances of HBV transmission within the family.