There are 1.2 million people living with HIV (PLWH) in the United States, an increase of 60% over the past 15 years.1 With approximately 50,000 new HIV infections each year and improved survival due to improved efficacy and access to treatment, the increase in HIV prevalence presents a challenge for primary prevention as the number of people with the potential to transmit HIV has grown. Periodic estimates show a stable number of annual new infections in the United States and reflect a decreasing transmission rate per person with HIV from 8 new infections per 100 in 1997 to 5 in 2006.
Ultimately, reducing the number of new HIV infections in the United States will require better implementation of effective prevention interventions. Working with PLWH to reduce their risk of HIV transmission to sex or needle-sharing partners offers potential gains in cost-effectiveness because it concentrates efforts on the estimated 1.2 million Americans with HIV rather than the much greater number of those at risk for infection. In addition, PLWH are more likely to be engaged with the health care system, presenting an opportunity for leveraging existing resources and systems for prevention.
Recent studies highlight the importance of prevention with people with HIV infection (PWP) and the linkage of primary prevention and treatment for HIV. PLWH who know they are infected reduce risky sexual behavior by about 60%,2 and antiretroviral therapy (ART) has been shown to reduce HIV transmission by 96% in a randomized trial among HIV-serodiscordant couples.3 Increasingly, the highest priority interventions for care and treatment of people with HIV such as HIV testing, linkage to care, and use of and adherence to ART are also high priorities for preventing HIV transmission.
The US National HIV/AIDS Strategy (NHAS) emphasizes the connections between prevention and care and identifies key goals related to prevention with PLWH.4 These include (1) increasing the percentage of PLWH who know their serostatus, (2) reducing the HIV transmission rate, (3) increasing the proportion of diagnosed persons linked to care within 3 months of diagnosis, (4) increasing the proportions of patients in continuous care, and (5) increasing the proportions of priority populations of infected persons with undetectable viral loads.
Effective evidence-based interventions for PWP are increasingly available. However, service coverage is currently incomplete at each of the following steps in the continuum from knowledge of infection status to successful reduction in transmission risk.
Knowledge of HIV infection status substantially reduces transmission risk behavior in people with HIV2 and is the gateway to accessing care and treatment services. An estimated 80% of persons with HIV are aware of their infection status,1 whereas the NHAS goal for 2015 is 90%.4 Considerable efforts are being made to increase this proportion, including CDC's Expanded Testing Initiative, in which 2.8 million HIV tests were conducted during 2007–2010, and more than 18,000 people with HIV were newly diagnosed.
LINKAGE TO CARE
Linking patients with providers of longitudinal HIV care is a critical step in accessing care and treatment and ongoing prevention interventions. Evidence-based interventions to increase linkage rates are available. However, only about 77% of HIV-diagnosed persons enter medical care within 3–6 months after diagnosis,5 whereas the NHAS 2015 goal is 85% linked to care within 3 months.4
RETENTION IN CARE
Retention in longitudinal HIV care is necessary to maintain access to care, treatment, and prevention interventions. Best practices to increase retention have been identified, but only 50%–60% of those who enter care remain in care over the long term.5 NHAS set a goal of 80% retention in care by 2015 for clients of the Ryan White HIV/AIDS Program.4
Effective interventions to assess risk and encourage behavior change have been identified,6 but only a minority of people with HIV is routinely counseled by their HIV care providers regarding behavioral risk reduction.5
ANTIRETROVIRAL TREATMENT AS PREVENTION
ART reduces the risk of HIV transmission,3 and new HIV/AIDS treatment guidelines recommend offering ART at any CD4 count to reduce the risk of HIV transmission.7 However, 10%–25% of PLWH in care are not receiving ART and, of those on ART, 15%–25% do not have an undetectable viral load.5,8 Efforts to increase use of ART need to focus both on patients and on providers who may not be aware of the benefits of early treatment and the current treatment recommendations.
Good adherence to ART is required to realize both the treatment and the prevention benefits, including increased survival and reduced transmission, however, adherence levels in practice are low and decrease over time. A recent systematic review has identified 8 effective interventions to increase HIV medication adherence.6
Taken together, the potential impact of increasing the use of these prevention interventions is enormous. But current implementation is suboptimal. It is estimated that as few as 20%–30% of people with HIV in the United States are aware of their diagnosis, in care, taking ART, and have a suppressed viral load.5,8 In addition, 26% of HIV-diagnosed men who have sex with men have had recent unprotected sex with an HIV-uninfected partner or someone with unknown infection status.9 Important barriers to full implementation of PWP interventions include challenging social, structural, economic, and contextual issues such as substance abuse and mental health problems, stigma, legal barriers, cultural and linguistic barriers, homelessness, and incarceration. Even as treatment of HIV improves and the individual and public health benefits are increasingly recognized, limited health care financing and capacity are critical barriers; in 2011, more than 9000 people with HIV in 13 states were on waiting lists to access the federal AIDS Drug Assistance Program.10
Despite the barriers and significant gaps in implementation, there is reason for optimism. The provisions of the 2010 Patient Protection and Affordable Care Act promise to expand access to health insurance coverage and care, especially for populations with high HIV disease burden, diagnosed and undiagnosed, such as young men, the poor, and those with pre-existing conditions, including HIV infection. The law provides that HIV testing and other preventive services be covered with no cost sharing and requires coverage of other essential health benefits, such as prescription drugs, laboratory services, chronic disease management, and treatment for mental illness and substance abuse. And it will improve the quality of care and accountability through interventions such as promoting effective prevention and treatment practices, developing performance standards for providers and payers, and establishing community-based health teams to support primary care practices. Even without full implementation of the Affordable Care Act, increasing focus on PWP and opportunities for prevention through health care can substantially reduce HIV transmission through awareness of status, risk reduction, and viral load suppression. The Affordable Care Act also mandated the creation of a National Prevention Strategy, which includes a focus on eliminating health disparities, including HIV, and prioritizes sexual and reproductive health as one of seven national prevention priorities. With concerted efforts of federal, state, and local health agencies; health care systems; community-based organizations; and, most importantly, people with HIV and their partners, ambitious goals for HIV prevention can be achieved.
1. Centers for Disease Control and Prevention. HIV Surveillance—United States, 1981–2008. MMWR Morb Mortal Wkly Rep. 2011;60:689–693.
2. Marks G, Crepaz N, Senterfitt JW, et al.. Meta-analysis of high-risk sexual behavior in persons aware and unaware they are infected with HIV in the United States: implications for HIV prevention programs. J Acquir Immune Defic Syndr. 2005;39:446–453.
3. Cohen MS, Chen YQ, McCauley M, et al.. Prevention of HIV-1 infection with early antiretroviral therapy. N Engl J Med. 2011;365:493–505.
4. The White House Office of National AIDS Policy. National HIV/AIDS Strategy for the United States. Washington, DC: The White House; 2010.
5. CDC. Vital signs: HIV prevention through care and treatment—United States. MMWR Morb Mortal Wkly Rep. 2011;60:1618–1623.
8. Gardner EM, McLees MP, Steiner JF, et al.. The spectrum of engagement in HIV care and its relevance to test-and-treat strategies for prevention of HIV infection. Clin Infect Dis. 2011;52:793–800.
9. Crepaz N, Marks G, Liau A, et al.. and HIV/AIDS Prevention Research Synthesis (PRS) Team. Prevalence of unprotected anal intercourse among HIV-diagnosed MSM in the United States: a meta-analysis. AIDS. 2009;23:1617–1629.