Intrafamilial transmission of hepatitis B virus in the eastern Anatolian region of Turkey.

Objective: To determine the possible route of hepatitis B virus (HBV) transmission throughout a family setting.
Method: Two hundred and forty family members (42 spouses, 32 offspring, 34 mothers, 35 fathers and 97 siblings) of 84 HBsAg carriers attending the Ataturk University Medical Faculty Hospital between July 2000 and May 2001, and 384 first time blood donors (control group) were screened prospectively for markers of HBV by using an ELISA. The chi-squared and Fisher's exact tests were used for statistical analysis.
Results: The prevalence of HBsAg and HBV infection among the family members (29.6% and 43.8%, respectively) was significantly higher than in the control group (9.6%, and 29.7%), P < 0.001. Among family members, the highest prevalences of HBsAg and HBV infection were in the husbands (70.0% and 90.0%, respectively), offspring (66.7% and 100.0%) of female index cases, and siblings (40.2% and 49.5%, respectively) of all index cases. Transmission of HBV to offspring was high in cases where both the parents were positive, but there was no difference in cases where only the mother or father was positive. Despite a high prevalence of HBsAg in the offspring of female index cases, HBsAg and anti-HBs seroprevalences in the mothers of index cases were not higher than the control group (P < 0.05). Thus, it appears that mothers do not have an important role in the acquisition of HBV infection.
Conclusion: In the area studied, in addition to the sexual route, both parents-to-child and sibling-to-sibling horizontal transmission might be the main route of intrafamilial spread of HBV infection.