How do doctors test for HIV drug resistance?
We can test for HIV drug resistance with tests called genotypes or phenotypes. The genotype test looks at the genetics of the virus to see if the virus has developed mutations of certain genes, which we have come to know are associated with resistance to certain HIV drugs. The phenotype test grows the virus in the laboratory in the presence of the HIV drugs to see if they no longer work. And if they no longer work in the laboratory against the HIV virus, then the virus is resistant.
