Intense intrafamilial transmission of HBV in a rural area in Egypt is a probable cause of non-response to vaccination: A cross-sectional-seroprevalence-community-study

Background: Worldwide, the prevalence of hepatitis B virus (HBV) infection is decreasing particularly in the vaccinated population. However, there are foci of increased transmission particularly in localized communities and within families. Objective: This study aimed at identifying HBV infection status among family members (FMs) of a cohort of HBsAg positive index cases (ICs) living in a village near Ismailia City, North-East Egypt. Design and participants: The study targeted ICs with chronic hepatitis B and their FMs. All were inquired for socio-demographic data, previous vaccination, kinship, and risk factors. All were tested for hepatitis markers and in HBcAb positive sera, HBV DNA and ALT were added. Results: The study included 96 participants including 14 ICs, 51 (53.1%) were females and 73 (76%) self-reported receiving hepatitis B vaccine after birth. Among 82 FMs, HBcAb was found in 49 (59.76%) of whom overt and occult HBV were diagnosed in 24 (49%) and 18 (36.7%). HBs Ag and HBcAb were more frequent in unvaccinated compared to vaccinated FMs; being 60.9% vs. 32.9% for HBsAg (p < /em>=0.017) and 91.3% vs. 57.5% for HBcAb (p < /em>=0.003). Among the FMs, active HBV were more related to male than female ICs (54.9% vs. 45.2%, p < /em>=0.73) while among children, it is more related to females more than male ICs (38.9% vs. 25%, p < /em>=0.33). In all HBsAg positive participants, HBeAg was negative and HBV DNA load was higher among female than male ICs (median 3500 vs. 2594.5 IU/mL, p < /em>=0.82). Conclusion: The study shows a high rate of HBV transmission among FMs of HBsAg carriers living in a remote area in North-East Egypt. Both overt and occult HBV infections were frequent despite previous vaccination