Preexposure Prophylaxis for HIV Prevention

Excerpt

While human immunodeficiency virus (HIV) infection is not curable, it is preventable. Yet worldwide, about 1.3 million people acquired HIV in 2022, approximately 130,000 of whom were children.[WHO. HIV Data and Statistics. 2023] In the United States, the number of people newly diagnosed with HIV amounted to more than 36,000 people in 2021, the most recent year for which data is currently available.[CDC. Basic Statistics. 2023] Transmission occurs most commonly via heterosexual contact in Africa, while in most other regions of the world, it occurs predominantly in those with male-to-male sexual contact. Rates of acquisition are often highest in people who inject drugs (PWID) or transgender people. The rates of HIV acquisition are decreasing worldwide due mainly to reduced transmission in Africa. However, some areas are experiencing increasing incident rates, notably Eastern Europe, Central Asia, the Eastern Mediterranean, North Africa, and Latin America.

Preexposure prophylaxis of HIV (PrEP) is an essential component of the recommended package for HIV prevention, according to the World Health Organization (WHO) and United States Centers for Disease Control and Prevention (CDC). Preexposure prophylaxis (PrEP) involves the intake of antiretroviral medications either continuously or for identified high-risk events and is highly effective in preventing HIV. Compared to placebo, consistent use of daily oral PrEP reduces the risk of sexual transmission of HIV by up to 92%. PrEP with bimonthly injectable cabotegravir lowers the chance of sexual transmission of HIV by about 70% compared to those taking tenofovir disiproxil fumarate/emtricitabine (TDF/FTC).[CDC. PrEP Guidelines. 2021] Though one trial of PWID observed individuals 40 years or older, those who used methamphetamines, and those with recent incarcerations had lower adherence than those without these risk factors, other studies have indicated the efficacy and cost-effectiveness of PrEP in preventing HIV in this population.

In 2015, the WHO first recommended PrEP to anyone who was at substantial risk for HIV infection as part of combination HIV prevention programs. Populations that may benefit from preexposure chemoprophylaxis are those with an HIV incidence rate of about 3 per 100 person-years or higher.[WHO. Consolidated HIV Guidelines. 2021] The addition of PrEP to locally available prevention measures is necessary to end global transmission of HIV, particularly in areas with a high burden of HIV. However, PrEP remains underutilized. In 2022, more than 2.5 million people worldwide received PrEP at least once, far short of the 10 million person target, but a considerable advance from 2019 when only 233,00 people were estimated to have received PrEP.[UNAIDS. Global Report. 2023]

HIV can infect individuals of any age, gender, race, or social class, and anyone who is sexually active or shares illicit drug equipment should be advised of the availability of PrEP. However, certain groups are at higher risk and are a global priority for the implementation of PrEP services: gay, bisexual, and other men who have sex with men (MSM); transgender individuals; people who trade sex for money, goods, or services; and people who share injection drug needles, syringes or other equipment.[UNAIDS. Global Report. 2023]

Whenever possible, PrEP should be started on the same day the client seeking PrEP or identified via screening to be at high risk for HIV acquisition presents to healthcare services after exclusion of active HIV and baseline creatinine testing.[CDC. PrEP Guidelines. 2021][WHO. Consolidated HIV Guidelines. 2021] Treatment with PrEP requires an ongoing commitment to connection with healthcare as part of a combination package that includes support, risk factor reduction, and counseling to improve treatment adherence. Individuals who regularly miss doses of their medication are at high risk for acquiring HIV.

However, barriers to PrEP treatment exist. In many countries, the availability of PrEP is limited or nonexistent despite increases in available therapeutic options. Even in countries with PrEP programs, availability remains limited for many in the highest-risk groups. Understanding local epidemiology, social context, and implementation science aids in developing policies, programs, and services that best serve the local population.

PrEP for HIV is an essential part of clinical HIV prevention and health maintenance. The rationale for PrEP, epidemiology of HIV transmission in high-risk populations, the identification of those at risk, treatment options, monitoring of PrEP, management of complications, client support for adherence to therapy, and individual, programmatic, and systems methods to enhance healthcare team outcomes in providing PrEP to clients are integral to HIV prevention. Using quality improvement and public health lenses ensures maximal benefit to those most at risk.

(See StatPearls' companion topic, "HIV Prevention," for further information on modes of transmission of HIV, pharmaceutical strategies for at-risk populations, implementation considerations for select populations, and select public health measures of relevance across the interdisciplinary team.)