Remarks: HBeAg appears in acute B hepatitis with or shortly after HBsAg, when the patient is most infectious. HBeAg is found only in HBsAg positive sera. During the HBeAg-positive state, usually three to six weeks, hepatitis B patients are at increased risk of transmitting the virus to their contacts, including babies born during this period. Exposure to serum or body fluid positive for HBeAg and HBsAg is associated with three to five times greater risk of infectivity than when HBsAg positivity occurs alone. Persistence of HBeAg is associated with chronic liver disease.