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.
HIV is a retrovirus that replicates quickly using reverse transcriptase, known for its lack of error correcting mechanisms, resulting in a high mutation rate.
Mutations that confer a substantial selective advantage to HIV survival can therefore quickly replicate within an individual, creating a new, resistant strain.
Several mechanisms of resistance have been identified, including mutations that block the incorporation of nucleosides, a class of HIV drug, into the viral DNA.
Missing doses of medication or taking them late poses a major issue because it can allow for the virus to once again begin to replicate inside the body.
[16] Current medical and scientific opinion is mixed on the most effective treatment methods, but is focused on drug cocktails and the importance of first-line regimens.
[18] The most successful treatments are combinations of three drugs used simultaneously, as this greatly reduces the probability of the virus developing resistance.
[20] Shortly after the advent of ART therapy, there was much controversy about how to make the drugs accessible to the developing world in countries where the disease was most widespread.
[12] These high adherence rates in resource-poor countries can be attributed to the success of community-based approaches like the HIV Equity Initiative in Haiti, which employed local workers and trained them in how to safely distribute HIV medication, as well as programs such as that in Brazil, in which generic drugs are able to be mass-produced and distributed for little to no cost.
[22][21] The number of people with resistant strains of HIV are growing, making the matter a more pressing issue for health care officials.
[3] New classes of drugs are constantly being researched and produced to help address the issue of resistance, as well as to try to alleviate the steep costs associated with managing HIV.