HIV drug resistance occurs when microevolution causes virions to become tolerant to antiretroviral treatments (ART). ART can be used to successfully manage HIV infection, but a number of factors can contribute to the virus mutating and becoming resistant. Drug resistance occurs as bacterial or viral populations evolve to no longer respond to medications that previously worked. In the case of HIV, there have been recognized cases of treatment resistant strains since 1989, with drug resistance being a major contributor to treatment failure. While global incidence varies greatly from region to region, there has been a general increase in overall HIV drug resistance. The two main types of resistance, primary and induced, differ mostly in causation, with the biggest cause of resistance being a