Induction of asymptomatic HBeAG carrier state in a patient with Down's syndrome following human bite

A 56-year-old Japanese male patient with Down's syndrome was bitten by a hepatitis B envelope antigen (HBeAg) carrier and become an asymptomatic HBeAg carrier without seroconversion. His mitogen response of T cells was poor compared with that of healthy controls. An impaired T cell response to hepatitis B virus infection may be responsible for the HBeAg carrier with Down's syndrome.