What’s the latest on biomedical prevention efforts for HIV globally?

By on .

Infectious Diseases experts give progress updates on treatment as prevention, prevention of mother-to-child transmission, and medical male circumcision

Julio Montaner, MD (far left), director of the British Columbia Centre for Excellence in HIV/AIDS presents at a Saturday session of the 49th Annual Meeting of the IDSA.

Treatment as prevention
“Really this is as good as it’s going to get in terms of preventing HIV transmission,” said Julio Montaner, MD, director of the British Columbia Centre for Excellence in HIV/AIDS at a Saturday session of the 49th Annual Meeting of the Infectious Diseases Society of America updating the audience on biomedical HIV/AIDS prevention interventions.

He was talking about the HPTN 052 study, which recently demonstrated a 96.3 percent reduction in sexual transmission of HIV to an uninfected partner when the HIV-infected partner starts immediate highly-active antiretroviral therapy (HAART) versus delayed therapy. Although the treatment as prevention mentality was surmised by many before this trial, HPTN 052 was the first, randomized, controlled trial to prove it.

“We embraced this thinking in British Columbia (BC) a number of years ago – and now we’re expanding HAART coverage in BC within the evolving  [International AIDS Society-USA] guidelines,” he said.

Montaner also noted a reciprocal decrease in new HIV diagnoses as antiretroviral therapy (ART) access increased, to include a study of injection drug users who saw a 50 percent decrease in new infections diagnosed in that community in 2007 when HAART was made more accessible to that population.

“Blood-born diseases and STDs remain a concern, they have not decreased,” Montaner said, “but we have seen a continued decrease in the number of AIDS cases being diagnosed.”  Rates of AIDS cases are down to 1995 numbers in Canada, mortality is down again, but this is not happening everywhere across the country despite the universal health care access situation, he said. “Access to care is very problematic in our country. There are places, like the prairies, seeing rising cases of HIV.”

In terms of the U.S., Montaner said only about 19 percent of the people infected with HIV have achieved undetectable viral loads with the use of ART. “We have a huge gap – we should be minimum around 50 to 60 percent of the people in order to have an impact on the U.S. epidemiological situation… Why are we not making it a priority to treat U.S. domestic cases?”

Prevention of Mother-to-Child Transmission (PMTCT)
Dr. Elizabeth Bukusi of the Kenya Medical Research Institute (KEMRI) painted a global picture of access to PMTCT services – where currently 21 percent of pregnant women in low- and middle-income countries are tested for HIV, 28 percent in sub-Saharan Africa, and 45 percent of HIV-positive pregnant women receive PMTCT services.

“If we really want to eliminate MTCT, we really have to be able to offer counseling and testing to every single pregnant woman we come into contact with,” Bukusi said. “We must aim to reach at least 80 percent – that they get counseled and tested, that those eligible to get ART receive it, and of those babies exposed, 70 percent must have access to co-trimoxazole,” to ward off HIV-related infections.

HIV prevalence among women peaked in 2000 at 13.4 percent in her country, and more needs to be done to ensure that the few clinicians that are there to treat these women can continue to provide care, such as task shifting. Nearly fifty percent of all HIV-infected females in Kenya have an unmet need for family planning services – there is a vast unmet need for contraception, a low contraceptive prevalence, and a high unintended pregnancy rate.

Other challenges, she said, include improving HIV testing rates among men when antenatal care clinics are where they succeed the most in testing, lacking political and national will to tackle these problems, no integration of HIV services such as with maternal and child health, and no national population-based numerical targets for testing, treatment or care.

Access, acceptance of testing, ART and advocacy for those in need were the key components of a strategy toward elimination of MTCT in low-resource settings, Bikusi said. Beyond ensuring women who are eligible are able to get the treatment they need, she said involving men in PMTCT – getting them tested for HIV, into care if need be, and providing access to prevention for men are important first steps.

MALE CIRCUMCISION and the buzz around devices
Economic models show that by increasing medical male circumcision (MC) coverage rates to reach 80 percent of men and boys in areas with high HIV prevalence and low MC, millions of lives and billions of dollars could be saved in the next ten to 15 years. Clinical trials have demonstrated MC is effective at protecting heterosexual men from HIV infection through vaginal intercourse by more than 60 percent, a benefit that improves over time.

“But we’ve only achieved 3.4 percent of the total coverage needed to reach 80 percent,” said Caroline Ryan, MD, MPH, director of Technical Leadership at the Office of the Global AIDS Coordinator (OGAC) during the session. Nearly twenty million MC are needed to reach the 80 percent coverage goal.

Zimbabwe is only at one percent of the needed coverage, Ryan said, although in the first six months of 2011, Tanzania has increased to 90,000 circumcisions up from 17,000 in 2010.

Two boys in Zambia wait at a medical male circumcision clinic for the procedure, one holding his permission form.

The slow progress has increased interest in utilizing medical MC devices – such as the PREPEX device. This “potential game changer” is safe, effective, doesn’t require a sterile environment, can be done by a single care provider and no anesthesia is needed, Ryan said. Moreover, there is minimal discomfort involved, meaning more men and boys may get it done and less school or work will be missed.

Data on the PREPEX device is only available from one country at present, and although the data is promising, more is needed from other countries, Ryan said. Another device, the Shang ring, does not have quite as many positive reiews as the PREPEX and field study data on its effectiveness are still needed.

The World Health Organization has not yet approved any devices and funds from the U.S. President’s Emergency Plan for AIDS Relief (PEPFAR) program are not available to support device-based services at this time.

“Eight hundred thousand voluntary medical male circumcisions have been undertaken in Southern/Eastern Africa,” Ryan said. “There is optimism that a device could accelerate scale up and lower the cost of implementation.”

 

3 thoughts on “What’s the latest on biomedical prevention efforts for HIV globally?

  1. touched souls

    512,000 mothers assisted at 91 sites for Prevention of Mother-to-Child Transmission (PMTCT) of HIV/AIDS here in Uganda. Uganda has ratified the Convention on the Rights of the Child (CRC).

    Recent results from clinical trials of potential new HIV prevention interventions underscore what we have known for decades: Wider delivery of effective behavior change strategies is central to reversing the global HIV epidemic. The availability of new biomedical HIV prevention modalities, such as vaccines and microbicides, is still many years away. Even when these tools finally emerge, human behavior will remain critical, as new prevention strategies are unlikely to be 100 percent effective in preventing transmission. With 2.5 million new HIV infections in 2007, there is an obvious and urgent need to pursue the effective strategies we have to promote safer behaviors.
    Human behavior is complex; widespread behavior changes are challenging to achieve; and there are important gaps in our knowledge about the effectiveness of HIV prevention. Yet the research to date clearly documents the impact of numerous behavioral interventions in reducing HIV infection. We also know that in all cases in which national HIV epidemics have reversed, broad-based behavior changes were central to success.
    To be more effective in the 21st century, the HIV prevention effort must confront several challenges of perception: misplaced pessimism about the effectiveness of behavioral HIV prevention strategies; unfortunate confusion between the difficulty in changing human behavior and the inability to do so; and misperception that because it is inherently difficult to measure prevention success—a “nonevent”—prevention efforts have no impact.
    Our (Touched Souls Uganda) focuses specifically on behavioral HIV prevention. The report surveys what we know about the effectiveness of behavior change strategies, what we still need to learn, and what we need to do to advance such efforts in coming years. Based on a comprehensive review of hundreds of studies of behavior change for HIV prevention, we find that the evidence base for behavioral HIV prevention is robust, with multiple studies documenting the effectiveness of interventions in numerous settings, among diverse populations, and throughout the course of the epidemic. Our review also indicates that the evidence base is not yet complete, and that important gaps and limitations remain in our knowledge about what works. Maximizing the effectiveness of prevention efforts requires that these limitations be acknowledged and addressed.

    Reply
  2. touched souls

    What We Need to Learn

    Although much evidence exists to demonstrate that it is possible to change human behavior to reduce the risk of HIV transmission, there are important gaps and limitations in what is known. There is also an inherent challenge in measuring the impact of any health effort that includes HIV prevention: measuring and determining causality for an event that did not occur (for example, an HIV infection averted) is intrinsically more complicated than evaluating an event or phenomenon that did happen. Some of the key limitations in what we know and areas in need of additional research follow:

    • M oving Fr Fr om Efficacy to Effectiveness: For both biomedical and behavioral interventions, it is often difficult to translate the impact seen in clinical trials (efficacy) into comparable results in the real world (effectiveness). Most clinical trials of behavioral HIV prevention programs have occurred in high-income countries, using intensive, professional program models that may not apply in more resource-limited settings or in different cultures. Few trials of behavior interventions have used such biological end points as incidence of HIV or sexually transmitted infections (STI), which potentially reduces confidence that behavior changes documented in clinical trials will have a public health impact in the real world.

    • G eneralizability: Even where there is evidence of effectiveness in real-world settings, key questions remain about the transferability of these successes to other communities, subgroups, and types of epidemics (for example, high-prevalence, concentrated, etc.)

    Reply
  3. shekari issaae

    this is really a needed piece especially in my country Nigeria, i will forward it to as many people as possible.
    health issues globally is moving from corrective to preventive and that is what we need;alot more campaign

    Reply

Leave a Comment

Your email address will not be published. Required fields are marked *