Ethnic and geographic variations in the prevalence of hepatitis A, B and C among aboriginal villages in Hualien, Taiwan

Background: Taiwan is endemic for viral hepatitis infections. A field survey was performed in the isolated aborigines in Hualien, eastern Taiwan, to investigate the geographic and ethnic variations in hepatitis epidemiology. Materials and Methods: From 1996 to 1998, blood was drawn from 1,748 subjects from two southern Ami and two northern Atayal villages for serum markers of hepatitis A, B and C. Results: Hepatitis A infection approached 100% in all groups. Hepatitis B infection and carrier rates were higher in the Atayal than in the Ami (92.3% vs 49.1% and 20.8% vs 5.3%; P < 0.01). Hepatitis C infection rates were higher in three villages (27.5%, 20.1% and 25.4% vs 3.6%; p < 0.01). Hepatitis C infection increased with age (p < 0.01) while hepatitis B infection did not. Conclusion: Hepatitis A infected most aborigines before the age of 15 years. Hepatitis B seldom infected people after the age of 15 yea rs, while hepatitis C continued to infect people who were older. Geographic factors are im porta nt for hepatitis C infection, whereas for hepatitis B infection, in addition ethnicity is also important.