Persistent Barriers to Optimal Care
These data support the need for effective HIV prevention and treatment programs for populations at high risk. A number of prevention measures are supported by a growing body of evidence,15-17 including:

  • Suppression of viral load in HIV-positive persons through the use of ART, also known as “Treatment as Prevention” (TasP)15,16,18,19
  • Post-exposure prophylaxis (PEP), effective if taken within 72 hours of a known HIV exposure,20 and
  • Pre-exposure prophylaxis, or PrEP, designed for use by individuals with confirmed HIV-negative status.15-17, 21-23 (See box, Evidence-based Strategies for HIV Prevention.)

Evidence-Based Strategies for Preventing HIV Infection

Antiretroviral therapy (ART)
Early initiation of ART to reduce viral load in people who are HIV-positive significantly reduces the chances of transmission to people who are HIV-negative.15,17,18,19 The 2016 PARTNER study in 14 European countries obtained data from 548 heterosexual and 340 MSM couples who reported having condomless sex. One partner was HIV-positive and taking ART and the other partner was HIV-negative. At a mean follow-up of 1.3 years per couple, there were no documented cases of within-couple transmission of HIV.19 The Centers for Disease Control and Prevention (CDC) notes that “people with HIV who take HIV medicine as prescribed and keep an undetectable viral load (or stay virally suppressed) have effectively no risk of transmitting HIV to their HIV-negative sexual partners.”15

Post-exposure prophylaxis (PEP)
Post-exposure prophylaxis (PEP) typically follows a CDC guideline-recommended 28-day course of 1 pill containing both tenofovir disoproxil fumarate (TDF) 300 mg and emtricitabine (FTC) 200 mg once daily plus either raltegravir 400 mg twice daily or dolutegravir 50 mg once daily.20 An alternative regimen for otherwise healthy adolescents and adults consists of TDF 300 mg/FTC 200 mg once daily plus darunavir 800 mg and ritonavir 100 mg once daily. Either regimen is intended to be started as soon as possible (within 72 hours) after a high-risk exposure. Post-exposure prophylaxis is not recommended if care is sought more than 72 hours after a potential HIV exposure. Afterward, an individual is retested for HIV at 4 to 6 weeks, 3 months, and 6 months after exposure.20

Pre-exposure prophylaxis (PrEP)
PrEP is a pharmacologic intervention that has shown great efficacy in preventing HIV infection.It is a fixed-dose regimen of 1 pill per day that contains 2 HIV medications, TDF and FTC, commonly known as Truvada.23 It is intended for use in individuals with confirmed HIV-negative status and is contraindicated in those who are HIV-positive or whose HIV status is unknown.23 HIV status must be confirmed every 3 months after beginning the regimen. The drug was approved for PrEP in 2012 after 2 large randomized, double-blind, placebo-controlled trials demonstrated its efficacy.21,22

One of the pivotal studies, iPrEX, evaluated PrEP among 2499 MSM and transgender women who have sex with men, all of whom reported high-risk sexual behaviors. Over the course of 4237 person-years, the use of PrEP resulted in a 42% reduction in the risk of HIV seroconversion compared with placebo.21 The other key study was the Partners PrEP study, which focused on 4758 serodifferent heterosexual couples in Kenya and Uganda. Based on 7827 person-years of follow-up, the risk reduction for PrEP compared to placebo was 75%.22 In both studies, efficacy was strongly correlated with adherence, based on post hoc analyses of plasma drug levels in 10% of study subjects.21,22

Current FDA approval is for once-daily administration of the medication. An alternative strategy is to take PrEP “on demand” — ie, before and after sexual activity rather than on a daily basis. A double-blind, randomized, placebo-controlled trial, ANRS IPERGAY, provides support for this method to be highly efficacious in HIV prevention for MSM. The authors calculated an 86% reduction in the risk of HIV infection.46

PrEP (daily oral tenofovir) has also been reported to reduce the risk of HIV infection by 49% (vs placebo) in a trial among more than 2400 injecting drug users in Thailand.47

A CDC initiative announced in February 2019 highlights 4 areas of strategic focus, with a goal of reducing HIV infections by 90% over the next decade4: (1) diagnosing HIV as early as possible, before disease has advanced, thus accelerating the timing of TasP,24 (2) treating HIV rapidly and effectively to achieve sustained viral suppression, (3) protecting people at risk for HIV through PrEP and other preventive approaches, and (4) responding rapidly to growing HIV clusters to stop new infections.4

A number of challenges may impede the implementation of these services. One of the main challenges is identifying patients who are likely to benefit from these interventions. Another is to overcome barriers in daily clinical practice, which are primarily related to the availability and accessibility of HIV prevention services.11

Availability refers to whether or not services exist at all within a given locale.11 Typically, underserved areas do not have adequate services available to them, including education on behavioral strategies (eg, low-risk sexual activities and condom usage) and pharmacologic interventions, such as TasP, PEP, and PrEP.11

Accessibility refers to the extent to which one is able to obtain HIV prevention services when they are available.11 One of the greatest barriers in patient access to adequate HIV prevention services is poor cultural competence among healthcare providers.25-30  Language barriers, for example, can prevent high-risk individuals from asking about prevention services and can impede clinicians from providing information about, and access to, those services.11 A limited understanding of individuals who are in sexually abusive/coercive relationships and domestic settings, reside in prisons or detention centers, and/or suffer from substance use and/or mental illness may also create barriers to adequate access and adherence to HIV prevention services.

The inability to handle potentially sensitive information about individuals from different cultures can negatively affect a relationship between a patient and a provider. Providers may not know how to approach questions related to sexual relationships and behaviors; drug and substance use; and economic, social, psychological, and cultural issues that may have an impact on HIV risk and access to prevention services.

Access to healthcare and preventive services is also hampered if providers are not aware of, or fully knowledgeable about, prevention options available in the community. For example, the CDC reported in 2015 that 1 in 3 primary care physicians and nurses were not aware that PrEP existed.31