Acute delta hepatitis without hepatitis B surface antigen detectable in the blood

The case is described of a 42-year-old man suffering from acute delta hepatitis without hepatitis B surface antigen (HBsAg) being detectable in his blood. Tests on the patient's blood were negative for anti-HBcIgM and HBeAg but positive for anti-HBs, anti-HBe, HDAg and anti-DIgM. It is well known that the delta antigen-antibody system is detectable only in HBsAg carriers except rarely in persons recently recovered from acute hepatitis B virus (HBV) and delta infection. We report one of the rare cases in which the circulating HBsAg as well as anti-HBcIgM and HBeAg were not found in the patient's serum, thus indicating the absence of recent infection with HBV.