The changing epidemiology of hepatitis B virus infection in the Canadian north.

Hepatitis B virus infections are common in the Eskimo (Inuit) populations of the world. In this study, serologic markers of hepatitis B infection were measured in 172 inhabitants (78%) of an isolated Canadian Inuit settlement. Evidence of hepatitis B infection was found in 22% of residents. The prevalence increased with age, being uncommon under the age of 20 (7%), yet present in the majority of inhabitants over the age of 40 (64%). Sera from four individuals (2.3%) were hepatitis B surface antigen- (HBsAg) positive. All four HBsAg carriers were negative for immunoglobulin M (IgM) antibody to hepatitis B core antigen (IgM anti-HBc), hepatitis B e antigen (HBeAg), and DNA polymerase, but positive for antibody to hepatitis B e antigen (anti-HBe). These data suggest that hepatitis B infection has become relatively uncommon in the inhabitants of this community born during the past 20-30 years. The apparent decline in prevalence did not appear to be related to recent demographic or socioeconomic changes in the area.