[Application of HBV gene subtyping method in study on familial transmission]

A cross-section epidemiological study for hepatitis B was conducted in the population of a village in Hebei Province. The prevalence rate of HBsAg was 3.75% (22/586), and HBV infection rate, 27.65% (162/586), without significant difference between males and females; and increasing with age. This village belongs to a low HBV incidence region in China. This phenomenon might possibly be related to the characteristic of the population (mostly blood donors) and high incidence of HCV (prevalence rate of anti-HCV was 10.31%, 59/572). The anti-HBc and overall HBV infection rate showed family clustering by binomial distribution analysis. The family clustering of HBV infection resulted mainly from the transmission from parents to their children and among the children. The overall positivity rate of HBV DNA was 24.77% (27/109), and the majority of the family members belonged to the same subtypes (72.22%). On the basis of HBV subtyping, familial transmission of HBV was classified into six types, ie. generational, horizontal, recessive, intra- and extra-familial, non-familial and undetermined ones.