Prevalence of delta infection in the western Pacific region.

The prevalence of coinfection and superinfection with the delta agent was studied in 2,645 hepatitis B surface antigen (HBsAg)-positive subjects from six countries and nine islands in the Western Pacific region. The study group comprised 262 patients with acute hepatitis B and 2,383 chronic carriers of HBsAg, of whom 278 were suffering from chronic liver disease or primary hepatocellular carcinoma. While major foci of infection were observed in Nauru, Niue, and Western Samoa, delta infection appears to be uncommon in other parts of the region.