The changing epidemiology of hepatitis B in Iran

Abstract

Hepatitis B is one of the most prevalent infectious diseases with 2 billion people infected worldwide, and 350 million chronic HBV carriers. At least one million chronically infected persons die annually of HBV-related complications, namely cirrhosis and hepatocellular carcinoma (1, 2), despite the availability of an effective vaccine (3). The prevalence of HBV carriers varies from 0.1 percent to 2 percent in low prevalence areas (United States and Canada, Western Europe, Australia and New Zealand), to 3 to 5 percent in intermediate prevalence areas (Mediterranean countries, Japan, Central Asia, Middle East, and Latin and South America), to 10 to 20 percent in high prevalence areas (southeast Asia, China, sub-Saharan Africa) (3-7). The prevalence of chronic carrier state in Iran had been reported to be 3% in 1980s (8). It is estimated that over 35% of Iranian have been exposed to the HBV and about 3% were chronic carriers (8). The wide range in HBV carrier rate in different parts of the world is largely related to differences in the age at infection, which is inversely related to the risk of chronicity. The rate of progression from acute to chronic HBV infection is approximately 90 percent for perinatally acquired infection, 20 to 50 percent for infections between the age of 1 and 5 years,