Excess mortality of hepatocellular carcinoma and morbidity of liver cirrhosis and hepatitis in HCV-endemic areas in an HBV-endemic country: Geographic variations among 502 villages in southern Taiwan

The aim of this study was to investigate excess mortality for hepatocellular carcinoma (HCC) and prevalence of hepatitis and liver cirrhosis (LC) in hepatitis C virus (HCV)-endemic areas in Taiwan, which is a hepatitis B virus (HBV)-endemic country. Tainan County, located in southern Taiwan, consists of 533 villages in 31 townships. A total of 56 702 subjects >= 40 years old (mean age, 60.9 +/- 11.8 years) were enrolled from 502 of the 533 villages between April and November 2004 (n >= 20/village). Serum blood HBV surface antigen (HBsAg), antibody to HCV (anti-HCV) and alanine transaminase (ALT) levels and platelet counts were measured. Township-specific mortality for liver cancer (ICD = 155) for both sexes between 1992 and 2001 were obtained from official publications. The prevalence of anti-HCV in Tainan County was 10.2% (township range, 2.6-30.9%; village range, 0-90.5%). The prevalence of HBsAg was 10.9% (township range, 5.5-17.2%; village range, 0-30.8%). The prevalence of hypertransaminemia (serum ALT > 40 IU/L) was 12.8%. At township levels, prevalence of anti-HCV (r(2) = 0.92, P < 0.001), HBsAg and anti-HCV (multiple r(2) = 0.94) were correlated with hypertransaminemia prevalence by single and multiple linear analysis, respectively. At village levels, prevalence of anti-HCV (r(2) = 0.52, P < 0.001), HBsAg and anti-HCV (multiple r(2) = 0.53) were each correlated with prevalence of hypertransaminemia, respectively. The prevalence of thrombocytopenia (< 150 000 platelets/mu L) was 5.5%, and adopted as a surrogate prevalence for LC. At township levels, prevalence of anti-HCV (r(2) = 0.58) was the only factor correlated by multivariate analysis with prevalence of thrombocytopenia. At village levels, prevalence of anti-HCV and female-to-male ratio (multiple r(2) = 0.43) were each independently associated with prevalence of thrombocytopenia. At township levels, HBsAg prevalence (r(2) = 0.42) was more correlated with HCC mortality than anti-HCV prevalence (r(2) = 0.28) for male subjects, while anti-HCV prevalence (r(2) = 0.45) was more correlated with HCC mortality than HBsAg prevalence (r(2) = 0.14) for female subjects. Prevalence of HBV and HCV infection were associated by multivariate analysis with both male (multiple r(2) = 0.62) and female (multiple r(2) = 0.53) HCC mortality. Prevalence of anti-HCV showed significant correlations with prevalence of hypertransaminemia, thrombocytopenia and liver cancer mortality. The findings indicate excessive mortality due to HCC, and LC and hepatitis prevalence in HCV-endemic areas in Taiwan, an HBV-endemic country.