genotype (or genotypic) – This term has several common uses:
1. a general term for the molecular structure of a living organism or virus.
2. a test that looks at the structure of an organism of virus (ie genotype resistance test looks for changes in the virus structure – called mutations).
3. a category for different types of similar viruses – ie hepatitis C has many subtypes, referred to as genotype-1, genotype-2 etc. HCV genotype is the strongest predictor of response to hepatitis C treatment.
See also phenotype.
high level resistance – when an HIV drug no longer works against the virus.
retinitis – inflammation of the retina (in the eye). CMV retinitis is an HIV-related infection that can cause permanent vision loss in someone with a CD4 count that is below 50 cells/mm3.
CMV section of the training manual.
compensatory mutation – this refer to an additional mutation, usually in the context of the fitness of a virus. For example, the mutations that stop a drug form working often stop the virus from reproducing as well. Additional mutations that return the virus to it’s former fitness are called compensatory mutations. They compensate for the reduced viral fitness. See revertant mutation.
