In order to clarify epidemiologic characteristics in the mode of transmission of the hepatitis B virus which are highly prevalent in this country, both HBsAg and anti-HBs measurements were made on 4,386 freshmen studen4s of a college together with que...
In order to clarify epidemiologic characteristics in the mode of transmission of the hepatitis B virus which are highly prevalent in this country, both HBsAg and anti-HBs measurements were made on 4,386 freshmen studen4s of a college together with questionnaire survey on risk factors associated with hepatitis B virus infection. Positive rates of HBsAg and anti-HBs were 5.7% and 17.1%, respectively The following factors such as sex, georaphic district and HBV vaccination have shown close association with the positive rates of HBsAg and anti-HBs but ABO blood type have not. Family contact seemed to be one of the most evident risk factors in the transmission of the virus with relative risk of 3.0. Drinking alcohol and smoking also played a role in acquisition of the infection with relative risk of 1.50 for the former and 1.39 for the latter. On the other hand, family size, formites, sexual behaviors, eating outside or visiting coffee-shops seemed not to be risk factors. The above results seem to suggest that multiple factors, not only poor environmental sanitary conditions but also socioeconomic status, immunologic responsiveness and genetic factors, may play important roles in the transmission of hepatitis B virus.