Six major strains (genotypes) of the
hepatitis C virus (HCV) cause infection. You may be
infected with more than one genotype at a time.
Genotype 1 is the most common strain in North America.
Genotypes 1, 2, and 3 are found
Genotype 4 is found throughout northern
Genotype 5 commonly is found in South
Genotype 6 is common in Asia.
Genotype testing is done with a blood test.
How genotype affects treatment
Although genotype tests are not used to diagnose HCV infection,
they may be done before treatment begins. Knowing the genotype may help a
doctor choose the best treatment plan. You should know your genotype before
The genotype of HCV does not appear to have any effect on the
severity of HCV infection or to affect your risk of developing cancer of the
ByHealthwise Staff Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine Brian D. O'Brien, MD - Internal Medicine Adam Husney, MD - Family Medicine Specialist Medical ReviewerW. Thomas London, MD - Hepatology