FACT SHEETw

ww

.glo

ba

lhe

alt

h.o

rg

Treatment as prevention: challenges and opportunities

“Treatment as prevention” refers to the prevention of HIV transmission by treating people living with HIV/AIDS (PLWHA) with anti-retroviral therapy (ART). PLWHA on ART have plasma viral loads up to six times lower than those not on ART.1 This means they have fewer copies of the HIV circulating in their bodies and are less likely to transmit the virus.

Evidence

Observational studies have shown that among heterosexual serodiscordant couples, PLWHA !on ART are five times less likely to transmit the virus to their partners than those not on ART.2

The World Health Organization currently recommends that PLWHA begin ART when their !CD4+ count drops below 350. A recent randomized control trial (HPTN 052) showed that starting ART earlier, when CD4+ count is between 350 and 550, can reduce HIV transmission between heterosexual partners by 96 percent.3 Studies have documented community-wide declines in HIV transmission as access to and use !of ART has risen.4 Though a causal relationship has not been proven, the declines may be due to reduced community viral load.

Test-and-treat

Given recent evidence on the efficacy of treatment as prevention, some advocate for a “test- !and-treat” policy that would support widespread, frequent HIV testing combined with imme-diate treatment of all positive cases. One model predicted that 55 percent more lives could be saved by 2050 by changing from the !current treatment strategy to a test-and-treat model.5 It also predicted that, given near-perfect implementation, universal voluntary testing and immediate treatment could move HIV into an elimination phase, even in high-burden areas.

Health systems and resource needs

Test-and-treat would require scale-up of HIV testing. In sub-Saharan Africa, people are often !diagnosed in the later stages of the disease.6 More frequent testing will be necessary to identify PLWHA in the early stages of the disease, particularly during the period of high infectiousness following infection.Implementing a test-and-treat policy would increase the number of people in need of treat- !ment while many health systems are still struggling to meet current demand. In 2009, only 36 percent of patients that were eligible for ART received treatment in low- and middle-income countries.6

Antiretroviral (ARV)-based prevention: Includes treatment as prevention as well as post-exposure prophylaxis (PEP), pre-exposure prophylaxis (PrEP), prevention of mother-to-child transmis-sion, and microbicides.CD4+ count: A measure of cells in the blood that reflect the status of the immune system; a declining count is an indicator of HIV progression.Community viral load: Amount of HIV circulating in an entire community, rather than in an indi-vidual.Serodiscordant couple: Sexual partners in which one partner is HIV-positive and the other is HIV-negative.

JUL

Y 2

01

1

1111 19th Street NW Suite 1120 Washington DC 20036 202.833.5900

Higher near-term costs could save money over the long-term by decreasing the number of infections, thus �reducing the burden on health systems in the future by freeing up resources and capacity.7

Ethics and human rights

The individual risks and benefits of early initiation of ART are not yet clear. � 4 It is possible that early treat-ment could produce side effects or that a longer treatment period could lead to chronic health conditions.There is concern that the community benefit of treatment as prevention could lead some governments to �institute mandatory testing and treatment policies, a potential violation of human rights and individual autonomy.

Drug resistance

Rapid scale-up of treatment without complementary patient support could lead to poor adherence to medi- �cation regimens, increasing the development of drug resistance.4

Close monitoring will be necessary to detect signs of drug resistance. Second-line drugs, though costly, must �be available to treat patients not responding to first-line medications.

Co-infection

Early initiation of ART is already recommended for PLWHA with tuberculosis, as it reduces morbidity �and mortality in those with both infections.8 The same may be true for other HIV-associated infections. Moreover, earlier ART could reduce transmission of these diseases at a community level.

Behavior change

Earlier treatment and education about treatment as prevention could possibly lead to decreased sexual inhi- �bition, including reduced condom use, if HIV risk perception was lowered.4

Ongoing research

A large, multi-country randomized control trial (strategic timing of antiretroviral treatment or START) will �compare immediate initiation of ART upon HIV diagnosis with initiation of ART when CD4+ count drops below 350.9 Results are expected in 2015.A U.S.-based study (HPTN 065) will explore rapid scale-up of community-based testing and treatment �referral.10 Because ART initiation will follow current treatment guidelines, the study will not technically follow a test-and-treat model. However, the results will provide important evidence about the feasibility of wide scale community testing and treatment.

References1. Kilby J, Lee H, Hazelwood J, Bansal A, Bucy R, Saag M, et al. Treatment response in acute/early infection versus advanced AIDS: equivalent first and second phases of HIV RNA decline. AIDS. 2008; 22: 957-62.2. Anglemyr A, Rutherford G, Egger M, Siegfried N. Antiretroviral therapy for prevention of HIV transmission in HIV-discordant couples. Cochrane Database of Systematic Reviews. 2011; (5).3. National Institute of Allergy and Infectious Diseases. Treating HIV-infected People with Antiretrovirals Protects Partners from Infection. NIH News: National Institutes of Health; 2011.4. Cambiano V, Rodger AJ, Philips AN. 'Test-and-treat': the end of the HIV epidemic? Current Opinion in Infectious Diseases. 2011; 24: 19-26.5. Granich RM, Gilks CF, Dye C, De Cock KM, Williams BG. Universal voluntary HIV testing with immediate antiretroviral therapy as a strategy for elimination of HIV transmission: a mathematical model. The Lancet. 2009; 373: 48-57.6. UNAIDS. UNAIDS report on the global AIDS epidemic; 2010.7. World Health Organization. Consultation on antiretroviral treatment for prevention of HIV transmission. Geneva; 2009.8. World Health Organization. Antiretroviral therapy for HIV infection in adults and adolescents; 2010.9. National Institutes of Health. Strategic timing of antiretroviral treatment (START). 2011 [cited 2011 July 14]; Available from: http://clinicaltrials.gov/ct2/show/NCT0086704810. Network HPT. HPTN 065 TLC-Plus: A study to evaluate the feasibility of an enhanced test, link to care, plus treat approach for HIV prevention in the United States. [cited 2011 July 14]; Available from: http://www.hptn.org/research_studies/hptn065.asp