UPDATE ON PREVALENCE, DIAGNOSIS AND TREATMENT OF HEPATITIS B VIRUS (Master Degree Thesis)

HBV is a Hepatotropic DNA-containing virus, discovered in 1966 by Blumberg. The virion of hepatitis B (Dane particle) consists of surface and core with a diameter of 42 nm (Kumar and Agrawal, 2004). The protein composition of HBV particles; either surface protein (HBs proteins) composed of LHBs (largest Hepatitis B proteins), MHBs (middle Hepatitis B proteins), SHBs (small Hepatitis B proteins) or core proteins; composed of HBc protein and HBe protein.

The world health organization (WHO, 2004) estimated that 2 billion people have been infected by HBV worldwide; of these more than 300 millions are chronically infected carriers of whom 25% are at risk of serious illness and eventually death from cirrhosis or hepatocellular carcinoma. The prevalence of HBV infection varies markedly throughout regions of the world; highly endemic in South East Asia, moderately endemic in Eastern and Southern Europe and low endemic areas as in North America (Tsai, 2004).

Concerning transmission of HBV; there is peri-natal transmission, sexual contact, blood and blood products, parentral drug abuse, opportunities for parentral infection, transmission in high endemic areas, exposure of unknown origin is still present.

As regards clinical presentation and sequelae; HBV can present as acute infection, fulminant hepatic failure (FHF), chronic hepatitis, extra-hepatic manifestations, post hepatitis B cirrhosis or combinations with HDV or HCV. Occult HBV infection is characterized by the presence of HBV infection with undetectable hepatitis B surface antigen (HBsAg).

Concerning the diagnosis of acute and chronic hepatitis B; the advances in molecular biology techniques led to the development of hybridization and polymerase chain reaction (PCR) assays for direct determination of HBV DNA. The diagnosis of HBV infection can also be made by the detection of HBsAg or HBcAg in liver tissues by immunohistochemical staining and of HBV DNA by Southern hybridization, in-situ hybridization, or PCR.

Treatment of chronic hepatitis B include Interferon therapy, nucleoside analogues such as Lamivudine, Adefovir Dipivoxil, Entecavir, Famciclovir, Emtricitabine/ coviracil, Combination therapy, Therapeutic vaccine, Gene therapy and Immunotherapy.

Prophylaxis against viral B infection is highly recommended using vaccination alone or combined with hepatitis B immunoglobulin for infants and individuals at risk of exposure.