Diseases & National Health Programme
What is the most important risk factor for becoming a chronic carrier following an acute episode of hepatitis B?
a. The likelihood becoming chronically infected with hepatitis B is inversely related to the age at which the infection occurs. Up to 90 percent of infants born to HBcAg-positive mothers will become carriers. Between 25 and 50 percent of children infected before the age of 5 will become carriers. Only 6 to 10 percent of acutely infected adults become chronically infected. The risk of becoming a chronic carrier is the same for men and women. Parenteral transmission is not associated with a higher risk of chronic disease compared with sexual transmission.
b. Although antigen dose may affect the risk of acquiring hepatitis B, it has no impact on chronic carrier status. Immunodeficiency may affect response to vaccine, but has not been proved to be a risk factor for chronic carrier status following an acute infection.