Issue Brief: The Prevention Benefits of HIV Treatment

Challenges and the Future of HIV Prevention

The landmark HPTN 052 clinical trial was conducted almost solely among heterosexual couples who, as part of the study, received frequent counseling related to HIV, sexually transmitted diseases (STDs), and family planning. Additional data are needed to estimate the prevention benefit of treatment for other populations, such as MSM, IDUs, and persons with acute or primary HIV infection,¹⁹ and in other settings such as North America and during routine clinical care.

As HIV treatment has evolved from a complicated regimen of numerous pills taken several times a day with severe side effects to a now once-daily pill with few side effects, some persons living with HIV may have become complacent about maintaining safer sex and safer injection use practices. Since HIV treatment became widely available in developed countries, several studies have shown a resurgence of HIV infections and increases in STDs, in particular syphilis, and especially among MSM.²⁰ Some studies have cautioned that the prevention benefits of effective ART would be offset by risk compensation, meaning that increases in risky sexual and injection-drug-use behavior might be observed as effective ART is widely disseminated.^21-23 However, results of one meta-analysis demonstrated that HIV-positive persons receiving ART, compared with those not receiving ART, did not show increased sexual risk behavior, even when therapy resulted in an undetectable viral load.²⁴ Yet, persons with HIV who believe that using ART or having a suppressed viral load protects them against transmitting HIV may be more likely to engage in unprotected sex or other risky behaviors. These behaviors might be amenable to change through prevention messages and other effective approaches.^24-27 Making sure that preventive behaviors are sustained in communities facing higher risk of HIV infection is crucial.²⁸

The future of HIV prevention will be shaped by operational and implementation research on the efficacy of combination prevention strategies, of which treatment may be one component.^29-31 Providing treatment to all HIV-infected persons will be an important step -- a recommendation that is included in the current Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents.³² The Department of Health and Human Services panel based its recommendations primarily on mounting evidence showing the harmful impact of ongoing HIV replication on AIDS and non-AIDS disease progression. In addition, the updated recommendations reflect emerging data showing the benefit of effective ART in preventing secondary transmission of HIV. Although the panel agrees that this public health benefit of ART is significant, its recommendations on when to begin ART are based primarily on the benefit of treatment to the HIV-infected individual.³² If treatment is to achieve its full prevention potential, current gaps in the HIV prevention, treatment, and care continuum must be narrowed or closed. Considerable changes in the US health care delivery system will be required to accommodate the increased demand for services that expanded testing, treatment, and linkage and retention in care will bring.³³

Now that early ART of HIV-infected persons has been shown to be very effective at preventing secondary transmission of HIV among individuals, the current goal is to determine the extent to which ART can be used broadly and effectively to reduce the spread of HIV within a population. At least two community randomized trials that use ART as their basis are planned,³⁴ and the results could determine the conclusive benefit of this successful intervention.³⁵

Still, resource constraints, logistical hurdles, emergence of drug-resistant viral strains, adherence to therapy regimens, and risk compensation remain concerns that scientists, health care providers, policymakers, and communities must confront if the individual and public health benefits of treatment are to be fully realized.³⁶

What CDC Is Doing

Much of CDC's funding supports and expands prevention services for persons living with HIV, including

• linkage to care and treatment, and interventions to improve retention in and re-engagement to care, prevention, and treatment for people living with HIV;
• referral to other medical and social services, such as substance abuse and mental health services; and
• behavioral interventions and other risk-reduction services for HIV-positive persons and their sexual or needle-sharing partners to reduce the likelihood of HIV transmission.

Three evidence-based interventions have proven effective in treatment settings and can be delivered by providers as brief messages during clinic visits: Partnership for Health, Options, and Positive Choice.

In addition, CDC's Prevention IS Care campaign also emphasizes ongoing, brief prevention counseling to help health care providers integrate, into routine care, simple approaches to prevent transmission by persons living with HIV. Medical visits provide a vital opportunity to reinforce HIV prevention messages, discuss sex- and drug-related risk behaviors, diagnose and treat other STDs, review the importance of medication adherence, and foster open communication between provider and patient.

Expanded HIV testing efforts will help more people know their status so that they can get life-saving treatment and will strengthen the impact of efforts to increase adherence to treatment, particularly in areas where large numbers of persons remain undiagnosed.

Additionally, CDC and the Health Resources and Services Administration (HRSA) have supported studies that suggest several promising opportunities to improve retention in care, including collaborating with other service providers to identify persons poorly retained in care, enhancing outreach programs, and addressing unmet psychosocial needs.^37,38

Summary

To realize the full prevention benefit of treating HIV infection, we should keep in mind four overarching tenets:

• HIV testing is the foundation for both prevention and care efforts.
• Early identification of infection empowers individuals to take action that benefits both their own health and the public health.
• Early treatment of infected persons substantially reduces their risk of transmitting HIV to others.
• The prevention benefit of treatment can only be realized with effective treatment, which requires linkage to and retention in care, and adherence to antiretroviral therapy.