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Posts Tagged ‘treatment as prevention’

This post is by Global Center Director Christine Lubinski, reporting this week from CROI in San Francisco.

The notion of treatment as prevention got a significant boost this week at CROI, where the results of a new study were presented by Deborah Donnell, MD, of the Fred Hutchinson Cancer Research Centre in Seattle. Dr. Donnell detailed exciting evidence that ART can prevent HIV acquisition, at least in the context of heterosexual, HIV discordant couples. 

In a multinational prospective study, researchers followed of a large cohort of couples in south and east Africa and looked at the role of ART in reducing transmission risks. The study tested the uninfected partner at the beginning of the study and at 3 month intervals, while providing free condoms and intensive prevention counseling to the couples. The infected partners were placed on ART when their CD4 counts dropped below 250.  Thirty-one percent of the infected female partners and 28 percent of the infected male partners reported unprotected sex.

The study was able to confirm whether HIV transmission occurred within the partnership through special testing.  There were 151 HIV transmission events, 108 of which were linked to partnerships.  Only one transmission event was found within a partnership where the infected person was on ART, while 102 HIV infections occurred within partnerships with no ART.  There was a 92 percent reduced risk of infection for the discordant partnerships where the partner was on ART. 

HIV transmission occurred at all CDR levels, but transmission rates were highest when the infected partners CD4 count was under 200.  This finding emphasizes the prevention imperative to expand ART access to the 40-some percent of persons in developing countries with CD4 counts below 200 who do not yet have access.

Interestingly, there was a significant reduction in unprotected sex in the partnerships where ART was introduced, from 6.2 percent to 3.7 percent.

Dr. Donnell noted that further research and more data is needed to evaluate whether prevention benefits would persist during long-term ART use. Click here to read a Reuters story on the study.

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This post is by Global Center Director Christine Lubinski, who is attending the Conference on Opportunistic Infections and Retroviruses (CROI) this week in San Francisco. This is her first post; check back regularly for her blogs throughout the conference.

The opening plenary of this leading HIV scientific conference—titled “Guiding the Global Response”—highlighted efforts to model the impact of ART as a prevention  and treatment tool to ultimately end the epidemic. CROI’s kick-off session also showcased issues related to couples and offered an assessment of current treatment strategies and scale-up in Africa.

In a talk entitled, “Put Your Money Where Your Model Is:  ART for Prevention and Treatment of HIV,” Brian  Williams, a modeler from South Africa asked why, despite the expenditure of $150 billion, the world has failed to control HIV transmission. He theorized that if an average of 7 people are infected by any one person, and if we reduce transmission 7 fold, we can eliminate HIV.  ART reduces viral load by 10,000 times, so if we start ART within one year of seroconversion and reduce Infectiousness by 70 percent, we can end the epidemic, Williams said.

While physicians and scientists are beginning to identify people early enough to save them from death, they are not intervening early enough to keep people from transmitting HIV to others.  He proposes a “test annually and treat immediately” strategy for low-prevalence settings, and a combination of test and treat and pre-exposure prophylaxis—or PREP—in high prevalence settings, like South Africa, which has a 17 percent HIV prevalence. Williams suggests that PREP would be appropriate for younger persons at high risk, while a test and treat strategy could be effectively deployed for older persons.  Benefits of this type of early intervention include a reduction in TB of about 60 percent.  Moreover, he noted that HIV-positive persons have a 2.5 times greater risk of mortality, compared to their HIV-negative counterparts, regardless of CD4 count or level of immunosupression.

Williams acknowledges that these strategies will require  a big initial capital outlay, but notes that we will ultimately save money in the long run.  If we don’t take measures to stem HIV transmission, we will continue to need huge fiscal resources to respond to the epidemic.  According to Williams, we can expect to spend $60 billion dollars, and the question is whether we will save millions of additional lives while incurring those costs.

He highlighted recent successful efforts at community-based testing in Kenya as an indication that test and treat could work. But an audience member responded that only about 30 percent of those identified as positive in this campaign were successfully linked to care and treatment.

Dr. Rebecca Bunnell, from the CDC, outlined the centrality of couples in the HIV epidemic in Africa and attributed the failure to significantly reduce HIV transmission rates in part to a failure to employ couple-based strategies.

She noted that the term “couple” describes many types of partnerships and that there are cultural, legal, and regional variations.  In a number of African countries in east and southern Africa, the majority of HIV-infected persons cohabiting are married.  Mutual knowledge of serostatus is low, and condom use is low. In east Africa, 40 to 50 percent of married HIV-infected persons have an uninfected spouse. There are an estimated 340,000 discordant couples in Kenya.  In Uganda, 74 percent of recent infections occurred in married couples. Studies have also shown that MSM who are part of a couple have a higher HIV risk than those who are not paired, as a result of more sex acts, more receptive sex, and less condom use. (more…)

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The idea of HIV treatment as prevention got a major boost yesterday in the wake of a WHO meeting in Geneva on the use of antiretroviral therapy as a way to curb new HIV infections.

“In the past, there has been a false dichotomy between prevention and treatment,” Teguest Guerma, interim director of the WHO’s AIDS department, told Bloomberg news, according to this story, as the WHO meeting wrapped up. “That is really what has been corrected. Prevention and treatment are two faces of the same coin.” Guerma said providing wider access to ARV drugs “will achieve a significant transmission benefit.”

His comments are likely to bring fresh attention to the debate over scale up of HIV programs. They come at the same time the WHO is considering changing in its HIV treatment guidelines to support earlier initiation of antiretroviral therapy, reflecting scientific evidence that such a move significantly enhances survival. With evidence mounting that wider access to ARVs would have benefits for everything from HIV prevention to AIDS mortality to tuberculosis control, the chasm between the need for ARVs and the funding for treatment seems to be getting wider by the minute. Let us know what you think about Guerma’s statement and these related issues.

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