Intrafamilial transmission of hepatitis B and C viruses in an Italian local health district.

The majority of investigations of HBV or HCV transmission were carried out on self-selected groups of people; the purpose of this study is to explore the routes of intrafamilial spread of HBV and HCV infection in a general population. Prevalence of hepatitis B and C virus markers was studied at various ages from 20 to 70 in a general population of 960 subjects of 422 households sampled from four towns. Serum specimens were collected for testing hepatitis B markers (HBsAg and anti-HBc) as well as hepatitis C antibodies (anti-HCV). The total prevalence of HBsAg was 5.8% and that of anti-HBc was 41.8%. The overall prevalence of anti-HCV was 4.7%. The odds on having HBsAg or anti-HBc infection for offspring with mother carrier are greater than for offspring with mother seronegative by a factor of about thirty and six respectively. Only anti-HCV positive mothers have a higher risk (OR = 12) of HCV infection in their offspring than in anti-HCV negative mothers. The risk on having a HBsAg or anti-HBc positive wife is significantly increased for exposure to a male partner respectively anti-HBc (OR = 5.6) or HBsAg positive (OR = 6.5), as compared with a male partner seronegative. A statistically significant risk of HBV infection (OR = 2.7) or carrier state (OR = 5.1) in husbands depends on the presence of anti-HBc positivity in their wives. There was no evidence (p >0.05) of a higher risk of HCV infection in spouses due to anti-HCV positivity in their partners. There is a higher risk in offspring exposed to mother seropositive for HBV or HCV infection in comparison with offspring not exposed. Evidence suggests that sexual contact does not play an independent role in the spread of HCV infection in the family setting as much as the HBV infection.