Attention A T users. To access the menus on this page please perform the following steps. 1. Please switch auto forms mode to off. 2. Hit enter to expand a main menu option (Health, Benefits, etc). 3. To enter and activate the submenu links, hit the down arrow. You will now be able to tab or arrow up or down through the submenu options to access/activate the submenu links.

Viral Hepatitis and Liver Disease

Quick Links
Veterans Crisis Line Badge
My healthevet badge

Hepatitis C Genotypes

for Health Care Providers

Genotypes - Hepatitis C

Hepatitis C Virus Genotypes

An important variable for all patients with chronic hepatitis C virus (HCV) is the "genotype" of HCV with which they are infected. This is the strain of the virus to which they were exposed when they were infected, often many years prior to their evaluation, and it is determined by a simple blood test. Genotypes of HCV are genetically distinct groups of the virus that have arisen during its evolution.(1) Approximately 75% of Americans with HCV have genotype 1 of the virus (subtypes 1a or 1b), and 20-25% have genotypes 2 or 3, with small numbers of patients infected with genotypes 4, 5, or 6.(2) Most patients with HCV are found to have only one principal genotype, rather than multiple genotypes.(3, 4, 5) Genotype 4 is much more common in Africa than in many other parts of the world, genotype 6 is common in Southeast Asia, and each area of the world has its own distribution of genotypes.(6)

Clinical Significance of Hepatitis C Genotypes

Genotype generally has not been found in epidemiological studies to play a large role in liver disease progression due to HCV. Rather, genotype is of clinical importance principally as a factor in selecting the appropriate HCV medications for treatment. Please see the HCV Treatment Considerations
for more information.


  1. Bukh J, Miller R, Purcell R. Genetic heterogeneity of hepatitis C virus: quasispecies and genotypesLink will take you outside the VA website.. Semin Liver Dis 1995;15:41-63
  2. McHutchison JG, Gordon SC, Schiff ER, et al. Interferon alfa-2b alone or in combination with ribavirin as initial treatment for chronic hepatitis C Link will take you outside the VA website.. N Engl J Med 1998; 339:1485-1492.
  3. Manns MP, McHutchison JG, Gordon SC, et al. Peginterferon alfa-2b plus ribavirin compared with interferon alfa-2b plus ribavirin for initial treatment of chronic hepatitis C: a randomized trialLink will take you outside the VA website.. Lancet 2001; 358:958-965.
  4. Fried MW, Shiffman ML, Reddy R, et al. Peginterferon alfa-2a plus ribavirin for chronic hepatitis C virus infectionLink will take you outside the VA website.. N Engl J Med 2002; 347:975-982.
  5. Hadziyannis SJ, Sette H Jr, Morgan TR, et al. Peginterferon alpha-2a and ribavirin combination therapy in chronic hepatitis C: a randomized study of treatment duration and ribavirin doseLink will take you outside the VA website.. Ann Intern Med 2004; 140:346-355.
  6. Simmonds P. Genetic diversity and evolution of hepatitis C virus - 15 years onLink will take you outside the VA website.. J Gen Virol. 2004;85:3173-88.