Using both tests together may not necessarily overcome this obstacle. Moreover, it is important to recognize that solid evidence proving the utility of these tests needs to be generated for a number of clinical situations. Further clinical trials and research will attempt to answer these questions. However, these strains are often too limited in number and strength to compete with wild-type virus, and they stand a good chance of being killed off by initiating combination antiretroviral therapy. After all, the purpose of combination therapy is to serve as a multipronged attack on such strains.
People harboring such virus can then transmit it to others.
Such cases are likely to increase dramatically in the near future. Two percent of patients had substantial resistance to at least one drug. Although presently neither genotypic nor phenotypic testing is being used by many healthcare providers for this purpose, recently released federal guidelines state that use of resistance testing be considered for selecting an initial treatment regimen. Although drug failure can also be used to describe the experience of people who must stop their medication because of intolerable side effects, it is most often associated with the presence of genetic mutations and decreased drug sensitivity. Viral load tests are likely to remain the most important tool for determining whether or not drug failure is occurring.