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

Abstract

Aims: 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.

Methods: Tainan County, located in southern Taiwan, consists of 533 villages in 31 townships. A total of 56 702 subjects >or= 40 years old (mean age, 60.9 +/- 11.8 years) were enrolled from 502 of the 533 villages between April and November 2004 (n >or= 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.

Results: 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 (r2 = 0.92, P < 0.001), HBsAg and anti-HCV (multiple r2 = 0.94) were correlated with hypertransaminemia prevalence by single and multiple linear analysis, respectively. At village levels, prevalence of anti-HCV (r2 = 0.52, P < 0.001), HBsAg and anti-HCV (multiple r2 = 0.53) were each correlated with prevalence of hypertransaminemia, respectively. The prevalence of thrombocytopenia (<150,000 platelets/microL) was 5.5%, and adopted as a surrogate prevalence for LC. At township levels, prevalence of anti-HCV (r2 = 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 r2 = 0.43) were each independently associated with prevalence of thrombocytopenia. At township levels, HBsAg prevalence (r2 = 0.42) was more correlated with HCC mortality than anti-HCV prevalence (r2 = 0.28) for male subjects, while anti-HCV prevalence (r2 = 0.45) was more correlated with HCC mortality than HBsAg prevalence (r2 = 0.14) for female subjects. Prevalence of HBV and HCV infection were associated by multivariate analysis with both male (multiple r2 = 0.62) and female (multiple r2 = 0.53) HCC mortality.

Conclusions: 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.