الفهرس 
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Abstract
INTRODUCTION
Since its discovery in 1989, hepatitis C has been recognized as a major worldwide public health problem.About 200 million people, 3% of the world’s population, are infected with hepatitis C virus (HCV) and 3 to 4 million persons are newly infected each year(WHO, 1999). The striking genetic heterogeneity of RNA genome of HCV is well recognized. Six major genotypes and over 50 subtypes and minor variants referred to as ”quasispecies” are described (Farci and Purcell, 2000).
HCV genotype 4 appears to be prevalent in the Middle East and Central Africa, where almost 13% of HCV carriers around the world live in the Eastern Mediterranean region. Prevalence rates of HCV genotype 4 ranges from 60% in Saudi Arabia to 90% in Egypt where it has been reported to be frequently associated with cirrhosis and a poor response to interferon (IFN) (Shobokshi et al., 2002).
Egypt has the highest worldwide prevalence of HCV, ranging from 6 to 28% (El-Sadawy et al., 2004) with an average of approximately 13.8% in the general population. These estimates lead roughly to 9 million persons who have acquired HCV infection and 7 million who had HCV chronic liver disease in 1996 (Sylvie et al., 2006).
In Egypt, the major route of exposure to HCV appears to be the mass parenteral anti-schistosomal treatment (PAT), with more than 35 million injections for more than 6million Egyptians given over a 20-year period (1960–1980). Although schistosomiasis was the major public health problem in the past, HCV has become the most important problem in Egypt (Frank et al., 2000).
HCV is a leading cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC), as well as the most common indication for liver transplantation in many countries. The rate of chronic HCV infection is affected by the age, gender, race, and viral immune response. Approximately 75-85% of HCV-infected persons progress to chronic HCV infection, and are at risk for the development of extrahepatic manifestations, compensated and decompensated cirrhosis, and HCC. The rate of progression to cirrhosis is highly variable, and is influenced by several factors. An understanding of the natural history of hepatitis C is essential to effectively manage, treat, and counsel individuals with HCV infection (Stephen and Timothy, 2006).