Treatment as prevention

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Treatment as prevention (TasP) is a concept in public health that promotes treatment as a way to prevent and reduce the likelihood of HIV illness, death and transmission from an infected individual to others. Expanding access to earlier HIV diagnosis and treatment as a means to address the global epidemic by preventing illness, death and transmission was first proposed in 2000 by Garnett et al. The term is often used to talk about treating people that are currently living with human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) to prevent illness, death and transmission. Although some experts narrow this to only include preventing infections, treatment prevents illnesses such as tuberculosis and has been shown to prevent death. In relation to HIV, antiretroviral therapy (ART) is a three or more drug combination therapy that is used to decrease the viral load, or the measured amount of virus, in an infected individual. Such medications are used as a preventative for infected individuals to not only spread the HIV virus to their negative partners but also improve their current health to increase their lifespans.^[1] When taken correctly, ART is able to diminish the presence of the HIV virus in the bodily fluids of an infected person to a level of undetectability.^[2] Consistent adherence to an ARV regimen, monitoring, and testing are essential for continued confirmed viral suppression. Treatment as prevention rose to great prominence in 2011, as part of the HPTN 052 study, which shed light on the benefits of early treatment for HIV positive individuals.

Evidence through observational, ecological and clinical trials reveal positive results in regards to the implementation of antiretroviral drugs as preventative measures against HIV transmission.^[3] Progress in scaling up access to treatment is brisk, and as of 2023 there are over 29 million people receiving antiretroviral therapy.^[4] Challenges to scaling access to treatment include cost^[5] and drug resistance.^[6]

TasP's legitimacy has influenced the World Health Organization's (WHO) 2015 shift from "test and wait" to "test and treat" recommendation, focusing on alerting as many people as possible of their HIV status through testing and starting them on ART treatment, regardless of their viral load or CD4 count.^[7] The diminished rate of new HIV infections brought about by these strategies are marked progress towards UNAIDS' 90-90-90 and 95-95-95 target to eliminate HIV/AIDS as a public health crisis by 2030.^[8] However, key populations in countries in Africa, Asia, and the Middle East may still have lower access to treatment.^[9] Understanding whether marginalized groups have access to testing and treatment are often hampered by harsh laws that do not allow for the accurate collection of data regarding these communities. Estimates of the number of people who are men who have sex with men, female sex workers, and/or drug users are very difficult to ascertain, rendering understanding diagnosis and access to treatment levels also difficult to determine.

TasP and test and treat to maximize access to early treatment is now the global standard for HIV prevention.