In China, the Nationwide Disease Surveillance and Monitoring System has reported HCC-related mortality to be 15 per 100 000 in 1991 and 21 per 100 000 in 2000; HCC mortality was higher in the rural population than that in the urban population, and higher in men than women. The prevalence of HBV infection is highly endemic throughout the world, with much higher prevalence in Asia and the Pacific Islands, sub-Saharan Africa, the Amazon Basin, and Eastern Europe.4 About three quarters of chronic HBV carriers live in the Asia-Pacific region and 15% to 25% of them will eventually die of HBV-related liver disease.5 Although

less than one third of the global population inhabits the Western Pacific region, defined by World Health Organization as 37 countries including China, Japan, South Korea, Philippines and Vietnam, it accounts for nearly 50% of all chronic HBV infection worldwide.6 The seroprevalence check details of HBsAg is generally lower in women than in selleck products men. Before the introduction of the HBV vaccine, the male-to-female

ratio was 1.4:1 in mainland China, 1.3:1 in Thailand and 1.1:1 in Hong Kong.7 Among Asian countries, the prevalence of chronic HBV infection also varies greatly. High-prevalence (≥8%) regions include mainland China, Taiwan, Korea, Philippines, Thailand, Vietnam, and South Pacific island nations. In China, nationwide survey in 1992 showed that the prevalence of hepatitis B surface antigen (HBsAg) was 9.75%, while the HBV infection rate in the general population was nearly 60%.8 Intermediate-prevalence (2%–7%) regions include central Asia, the Indian subcontinent, Indonesia, Malaysia and Singapore. Australia and New Zealand belong to the low-prevalence (< 2%) countries, selleck kinase inhibitor but the prevalence has increased in recent years due to immigrants from high-prevalence countries.9 In Asian regions with high HBV endemicity, most HBV infection occurs within the first five years of life.10 In China, the prevalence of HBsAg in un-vaccinated children at the age of one already reached

that of the general population, implying that chronic HBV infection starts in early life in most patients.8 Therefore, vaccination against HBV infection in early life, especially during infancy, is of paramount importance for prevention of chronic HBV infection in adults. By the end of 2006, 168 countries had implemented an universal HBV immunization program for newborns, infants and/or adolescents.2 HBV vaccination has already changed the epidemiology of chronic hepatitis B in Asia. There were high rates of chronic HBV infection (7.8%–13%) in Cambodian blood donors before the introduction of HBV vaccination (World Health Organization 2002, unpublished data).11,12 The seroprevalence among Cambodian immigrants (15–92 years of age) in Australia was 8% before the era of vaccination.13 A more recent study in Cambodia to evaluate the impact of hepatitis B vaccination programs showed HBsAg seroprevalence of 3.5% among five-year-old children.