HCV genotype
There are at least six different strains of hepatitis C, known as genotypes.
They are numbered from 1-6, in the order that they were discovered. Each genotype has variations, called subtypes. Subtypes are named by lower-case letter (i.e. a, b, c, etc). One genotype cannot change into another, but it is possible to catch more than one genotype at the same time, or to catch a different genotype from the one you already have. You can also catch the same genotype again after successfully clearing the virus with treatment.
It is essential to know your HCV genotype in order to plan when to use treatment and how long to treat for. If your clinic hasn’t done this, then be more insistent.
This is strongly recommended in the British HIV Association (BHIVA) guidelines for treatment of HIV and HCV coinfection.
Table: Predominant hepatitis C genotype by region
| Region | Predominant HCV genotype |
|---|---|
| Europe, North America, Japan | Genotype 1a or 1b (genotypes 2 and 3 are less common) |
| Southeast Asia | Genotype 3 |
| Egypt, the Middle East, Central Africa | Genotype 4 |
| South Africa | Genotype 5 |
| Asia | Genotype 6 |