hepatitis C virus

HISTORICAL BACKGROUND The hepatitis C virus is a small, spherical enveloped RNA virus approximately 50 nm diameter. Its buoyant density in sucrose is only 1.06 g/cm3 but much of the virus in chronically infected individuals appears to be bound to antibody, which imparts a higher density of approximately 1.17g/cm17. Genomic organization of hepatitis C virus shows A 5’ non-coding (NC) region consists of approximately 340 nucleotides and contains an apparent internal ribosomal entry site (IRES). Immediately downstream is a single large open reading frame (ORF) of approximately 9,000 nucleotides, encoding a large poly protein precursor of approximately 3,000 amino acids that is co-translationally or post-translationally cleaved into separate proteins by a combination of host and viral proteases. A capsid protein, two envelope proteins (E1 and E2), and a small protein (P 7) of unknown function are encoded in the 5’ region of the ORF. At least six nonstructural proteins, including protease, helicase, and RNA polymerase enzymes and regulatory peptides, are arrayed in the 3’ portion of the ORF. Finally, there is a 3’ NC region that consists of approximately 50 nucleotides, a polypyrimidine tracked and a highly conserved terminal sequence of approximately 100 nucleotides. Testing for HCV infection typically involves analysis of a serum sample for anti-HCV antibody and for viral genomic DNA. However, current diagnostic tests are often limited in the sensitivity ith which they can detect genetically and serologically altered HCV strains. The mechanism of liver injury in acute and chronic hepatitis C type is unknown, but since there is little evidence as to the cytopathogenicity of HCV, it is thought that liver damage may in fact be mediated by the host’s cellular immune response to the infection. Given the lack of definitive symptoms, liver histology and the circulating levels of liver enzymes are currently considered to be the most reliable predictors of progression to cirrhosis. Studies show that severe necro-inflammatory activity, as well as severe fibrosis in hepatic tissue, both due to elevated levels of liver enzymes can be correlated with progression to cirrhosis within 10 years. In cases where inflammation and fibrosis is mild, progression is slowed and even limited Factors influencing the rate of progression of chronic hepatitis C to cirrhosis and liver cancer include alcohol abuse, the duration of the infection and possibly viral titer. REFERENCES: 1. Khan R U. A case – control study of Risk factors associated with hepatitis C infection among pregnant women in hospitals of Karachi Pakistan 2006. (1-4) 2. Ghaz H O Hepatitis C virus in pregnancy Umma-Qura univ J Sci Med Eng [2007]; vol 19; No. (137-144) 3. Shah F U, Salih M, Malik I A, Hussain I. Increasing prevelance of chronic hepatitis and associated risk factors. Pak J Med, 2002; 41(2):1-8. 4. Haider Gulfareen, Zehra Nishat, Munir A A. Hepatitis C Freequency, Risk factors and pregnancy outcome 2009. JSur, 2009; 14(1) 5. Shaikh F, Naqvi S Q H, Jilani K, Memon R A D. Prevalence and Risk factors for Hepatitis C Virus during pregnancy. Gomal J Med 2009 Vol 7, No. 2 6. Roberts A.E, Yeung Latifa Maternal infant transmission of hepatitis C virus infection 2006 (S106-S113) 7. Martin j. C. Preganant with Hepatitis C: Preventing Mom-To-Child Transmission 2005; (1-3) 8. Baker N Philip. Perinatal infections obstetrics by Ten Teachers 2000; 16(200-219) 9. Yee J L, Weiss L H, Langner G R, Herrera J, Kaslow A R, Leeuwen J D Risk factors for acquisition of hepatitis C virus infection: a case series and potential implications for disease surveillance 200 10. Kumar A, Sharma A, Gupta R.K, Kar P, and chakravarti A. Prevalence and risk factors for hepatitis C virus among pregnant women. Indian J M 2007; vol 26: (211-215) 11. Summaries for patients. Hepatitis c virus infection in the United States 1999 through 2002. Ann Intern Med 2006; 144:120 12. Zhou DX, Tang NL, Tam JS et al, Hepatitis C virus genotype distribution among intravenous drug user and the general population in Hong Kong J Med Virol. 2006; 78: 574-81. 13. Parkin SP, Khan Hl, Cubitt WD. Detection of antibodies to hepatitis C virus in dried blood spot samples from mother and their offspring in Lahore. Pak J Clin Microbiol 1999; 37; 2061 14. Roy KM, Goldberg D, Taylor A, Mills P. Investigating the source of hepatitis C virus infection among individuals whose route of infection is undefined: a study of ten cases, Scand J Infect Dis 2003; 35: 326-28. 15. Benjelloun S, Bahbouhi B, Sekkat S, Bernnani A. Had N, Benslimane A. Anti-HCV seroprevalence and risk factors of hepatitis C virus infection n Moroccan population groups. Res Virol 1996; 147:247-255. 16. Robinson JW, Rosas M, Guzman E, Patarroyo ME, Moreno A. Comparison of prevalence of anti-hepatitis C virus antibodies in differing South America population. J Med Virol 1996; 50: 188-192. 17. Alter MJ, Mast EE, Moyer LA, Margolis HS. Hepatitis C, infect Dis Clin North Am 1998; 12:13-26. 18. Guadagnino V, Stroffolini T, Rapicetta M, Costantino A, Kondili LA. Prevalence, risk factors and genotype distribution of hepatitis C virus infection in the general population: a community-based survey in south Italy, Hepatology 1997; 26: 1006-1011. 19. Esteban JL, Lopez-Talavera JC. Gensca J. Madoz P. Viladomia L. Muaniz E, Martin-Vega C. High rate of infectivity and liver disease in blood donors with antibodies to hepatitis C virus. Ann Intern Med 1991; 115:443-449. 20. Report of a WHO consultation organization in collaboration with the Viral Hepatitis Prevention Board, Antwep, Belgium. Global surveillance and control of hepatitis C. J Viral Hepat 1999; 6:35-47. 21. Takahashi M, Yamanda G, Miyamoto R, Doi T, Endo H,Tsuji T, Natural course of chronic hepatitis C. Am J Gastroentrol 1993; 88:240-243 22. Roy KM, Goldberg D, Taylor A, Mills P. Investigating the source of hepatitis C virus infection among individuals whose route of infection is unidentified: a study of ten cases. Scand J Infect Dis 2003; 35; 326-328. 23. Laurer GM, Keefe EB, Ahmed A. The epidemiology of HCV infection, J Clin Gastroenterol 2003; 36:47. 24. Yusuf A, Muhammad A, Ishaq M. Can we afford to operate on patient with HBsAg screening. J Coll Physicians surg Pak1996;9:98-100. 25. Malik IA. Legters IJ. Luqman M. The serological markers of Hepatitis A and B in health population in northern Pakistan. J Pak Med Assoc 1988; 38:67-72. 26. Umer M, Bushra HT, Shuaib A. Spectrum of chronic liver diseas due to HCV infection. J Coll Physicians surg Pak 1999;6:234-237. 27. Wasim J, Nadim J, Jved Y. Hepatitis B and C prevalence and risk factors associated with seropositivity among children in Karachi, Pakistan. BMC infect Disease 2006;6:101-103. 28. Parker SP, Khan HI. Cubitt WD. Detection of antibodies to Hepatitis C virus in dried blood spot samples from mothers and their offspring in Lahore, Pakistan J Clin Microbiol 1999;37:2061-2063. 11. Terrault N A. Sexual Activity as a Risk factor for hepatitis C hepatology 2002 (1-6) 12. Massari M; Petrosillo N, Ippolito Giuseppe, solforosil, Bonazzil, Clementi M, and Manzin A. Transmission of hepatitis C virus in a gynecological surgery setting JCM 2001; vol 39; No 8 13. Mboto Ci , Andy iE, Eni O I, Jewell A P. Prevalence, socio demographic characteristics and Risk gactores for Hepatitis C infection among pregnant women in Calabar Municipality, Nigeria [Online] 2010, 10(2)L 116-120 14. Khattak S T, Marwat M A, Khattak I D, Khan T M, Naheed T. Comparison of frequency of Hepatitis B and Hepatitis C in pregnant women in urban and rural area of district swat. J Ayub Med Coll Abbottabad. 2009; 21(2) 15. Wodak A. An over view of Hepatitis C in st. vinvent’s hospital darling hurst NSW 2010 16. Landes M, Newell M L, Barlowp, Fiores, Malyuta R, Martinelli P, Posokhoya S, Sarasiv, Semenenko, Stelmah A, Tibaldic and Thomec. Hepatitis Bor Hepatitis C Coinfection in HIV infected pregnant women in Europe. British HIV Medicine 2008: 9(526-534) 17. Murphy E L, M Stephen, Bryzman A simon, Glynn A met. Thomason Ruth A, Williams Alan E, Nass Catherie C, Ownby Helen E, B George, Sehreiber, Kong fanhul, R Keith, Neal, and George J Nemo. Risk factors for hepatitis C virus infection in united states blood donors. Hepatology 2000; vol 131, No. 3