Can we stop HIV now?

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Post by David Menadue02 Mar 2012

"We have been sitting on roughly 1,000 new HIV transmissions per year in Australia for several years now. It’s time we upped our game and lowered the number of new cases of HIV we see in this country. We can lead the world in achieving virtual elimination of HIV among populations at high risk in Australia, including sex workers, injecting drug users and men who have sex with men (MSM). What is needed is political will."

With these words, long-time HIV activist Bill Whittaker ignited a new push to increase HIV prevention efforts in Australia in a passionate speech to the 2011 National HIV/AIDS Conference in Canberra. He was responding to the recent UN Declaration on HIV endorsed by all countries which set a global target of reducing sexual transmission of HIV and infections from injecting drug use, by 50% by 2015.

The Declaration also includes a commitment by all countries to eliminate mother-to-child transmission of HIV by 2015 through the use of antiretrovirals during pregnancy and birth: something that has been virtually achieved in Australia.

Whittaker went even further, urging Australia to set itself a target of an 80% reduction of sexual transmissions by 2015 among MSM and the virtual elimination of infections among sex workers and injecting drug users. This, he said, would involve revitalising HIV prevention campaigns and taking advantage of new biomedical prevention and testing strategies about to become available. He also argued that Australia should be able to get 90% of HIV-positive people on antiretroviral treatment by 2013.

These new developments in HIV prevention and treatment raise the possibility that, rather than waiting for some ‘magic bullet’ that will end HIV, we could make a major impact on dramatically reducing HIV infections now and maximising the health of HIV-positive people, if there is sufficient political will in Australia and other countries.

RAPID TESTS
New rapid HIV tests are one way that more people might be encouraged to find out their HIV status. These tests, yet to be licensed in Australia, should increase the access to and convenience of getting an HIV test. They provide a result within 30 minutes of a blood test.

Several trials of rapid tests are occurring around the country to test their accuracy and acceptability.

If communities at particular risk, such as gay men, take up rapid testing, this would be likely to increase the number of people who know their HIV status. It has been estimated that approximately one-third of new infections are transmitted by people who don’t know they are HIV-positive. If people know they have HIV, they are more likely to consider treatment to benefit their own health and reduce the chance of transmitting HIV to others.1

PRE-EXPOSURE PROPHYLAXIS (PREP)

The effectiveness of using HIV treatment for prevention in HIV-negative people was shown in the IprEx study, which released results in 2011. It was a study of men and transgenders who have sex with men in multiple sites around the world. It showed a reduction in infections of 44% in the cohort although this increased to 73% amongst those who took the drug (Truvada) more consistently.

In San Francisco there was a much better result with 95% of those on the treatment arm having undetectable viral load and no infections recorded among those who took the drug.

Getting PREP approved in Australia is likely to involve some challenges.

Will governments accept the argument that a drug to prevent HIV infections is worth funding when condoms are a lot cheaper?

Will gay men and other groups at greater risk of HIV take the drug if a daily dose is required?

HIV educators say that no amount of condom campaigns will stop all risk behaviours in the gay community, and that a drug to help reduce infections (particularly amongst serodiscordant couples, for instance) will save considerable health costs to government over time.

The iPrEx study showed that condom use rates remained steady. If this was the case when PREP was introduced here, it would serve as an added form of risk reduction rather than a replacement for condoms.

The iPrEx study is ongoing, with all participants taking Truvada this time, and will gather further information about dosing levels and the acceptability and effectiveness of PREP over time.

TREATMENT IMPACT ON HIV TRANSMISSION

Last year the HPTN 052 trial showed that 96% of heterosexual couples enrolled did not pass on HIV from the positive to negative partner, when the positive partner was on treatment and had an undetectable viral load .This led to a renewed interest from countries around the world in providing treatments to people with HIV to prevent further infections.2

‘Test and Treat’ policies (where people are treated on diagnosis) have been adopted in San Francisco, New York and Washington DC, with many other US states expected to follow.

Recently, the South African government announced a plan to provide treatments to 80% of eligible people with HIV in that country.

With 5.6 million infected, the government decided that the only way to reduce such a toll on society was to increase opportunities for testing and then to treat as many as possible, thereby helping reduce new HIV infections.

The HPTN 052 study is good news for heterosexual couples where one partner is HIV-positive. The study did not look at gay couples and it is unclear how directly translatable the 052 findings are for MSM.

In recent years, San Francisco, which has an HIV prevalence of 24% in its MSM population, has been implementing a policy that recommends all people with HIV start treatment, regardless of CD4 count.

Researchers from the University of California (San Francisco) estimate that this may lead to a decrease in new infections at five years of between 59% and 76%.3

San Francisco has already seen a significant reduction in new infections from 864 in 2004 to 506 in 2009, which researchers attribute to getting more people on treatment and the consequent decrease in levels of HIV in the community.4

Researchers from the Kirby Institute in Sydney suggest this San Francisco modelling may be overly optimistic for gay men. They have begun a trial in several Australian cities, called Opposites Attract, where they are investigating rates of transmission amongst a cohort of gay serodiscordant couples to see whether the risks involved with anal sex may be higher than for penile-vaginal sex, even with the HIV-positive partner having an undetectable viral load .5

THE LIFE EXPECTANCY OF HIV-POSITIVE PEOPLE ON TREATMENTS IS NOW SIMILAR TO THOSE WITHOUT HIV ALTHOUGH THE OVERALL MORTALITY RISK IS A LITTLE HIGHER

TAKING UP TREATMENTS EARLIER

One of the main strategies Whittaker is proposing to decrease infections is to encourage HIV-positive people to start antiretroviral treatment earlier. The US Department of Health and Human Services HIV Treatment Guidelines already recommend HIV treatment for all people with CD4 counts of 500 and below.

Australia, like many other countries, usually follows the US DHHS Guidelines.6

Experts are divided about people with a CD4 count above 500. Some recommend treatment for all, while others believe this should be considered on a case-by-case basis. A key factor in favour of earlier treatment is increasing evidence of HIV’s ongoing damage to the body and evidence that being on treatment may decrease damage done by the virus. It also reduces the risk of developing problems associated with HIV disease, including cardiovascular disease, cancer, bone disease and neurological complications.

A recent EuroSIDA study of 12,000 patients on cART (combination antiretroviral therapy) found that long-term use of these treatments was safe and did not raise the risk of death from non-AIDS-related illnesses. The life expectancy of HIV-positive people on treatments is now similar to those without HIV, although the overall mortality risk is a little higher.7

Those hesitant to support earlier treatment say there is insufficient evidence of clinical advantage to treat above a 500 CD4 count — although there is no evidence to say that it does any harm either. Some doctors say that some patients are not ready to take antiretrovirals early in their diagnosis and need some time to commit to the idea. Many are waiting for the results of the START study, a multi-centred clinical trial being conducted in 30 countries, including Australia, which aims to answer the question of whether early treatment is better than deferred treatment. START randomises participants to receive HIV treatment immediately or to wait until their CD4 count is less than 350 or they have clinical signs of progressive disease. The trial is not due to conclude until 2015 although there may be earlier progress updates before then.

Some experts recognise that the START study is potentially very valuable, but argue that the new scientific information that has emerged since START began means we can’t afford to wait for its results before offering early treatment and treatment for prevention.

WHY SOME POSITIVE PEOPLE DON’T TREAT

The Tracking Changes study from the Australian Research Centre in Sex Health and Society was released in January 2012. It looked at the perceived barriers for some HIV-positive people going onto treatments from the perspective of clinicians and HIV-positive people themselves.8

Clinicians said that a major concern of patients was the perceived side-effects of medications. Rachel Koelmeyer, an investigator on the study, said that it seems some newly diagnosed people still had outdated ideas of the nasty side-effects of treatments, possibly gained from seeing people with lipodystrophy (body shape changes) in the past. Some community views about HIV treatments being toxic or ‘not natural’ were still prevalent, even though they have improved markedly in recent years, with minimum side-effects for most people.

Koelmeyer said clinicians reported that some people take longer than others to psychologically adjust to the idea of taking treatments.

They also found younger people were concerned about the impact on their lifestyle of taking treatments — they needed to be assured the process was going to be easy, she said.

WHERE TO FROM HERE?

To deal with some of these barriers to the uptake of treatments, Whittaker says: "We need new HIV information campaigns to bring people up to date with the latest information about new treatments, the health benefits of early treatment and the role of treatment in helping reduce new HIV infections."

Whittaker says that all the states and territories, the Commonwealth government and community-based organisations need to make a strong commitment to action to achieve the goal of an 80% reduction in new HIV infections by 2015. Funds will need to be allocated for new campaigns to raise awareness about the benefits of HIV treatments as well as to re-enforce proven prevention strategies such as the use of condoms for safe sex.

The process of generating the political will to set and reach ambitious targets for treating HIV and reducing new HIV infections has started already. All state and territory governments have committed to set such targets to reduce HIV infections, and a special working group has been set up to work out the details. Many HIV sector agencies (including the Boards of NAPWHA and ACON) have agreed to support clear and ambitious new prevention and treatment uptake targets.

Over the coming months it is likely that more research results will emerge supporting the benefits of earlier treatment and the secondary benefit HIV treatment has in helping prevent new HIV infections, including at international HIV conferences.

"Governments and community must act together now, because prevention and treatment delayed by inaction is prevention and treatment denied. Failure to act on new scientific information will only result in poor health outcomes for people with HIV and avoidable new HIV infections," Whittaker concluded.

  1. Wilson D.P. et al, Importance of promoting HIV testing for preventing secondary transmissions: modelling the Australian epidemic among men who have sex with men Sex Health 2009;6:19-33
  2. Cohen M.S. Chen Y.Q. et al, for the HTPN 052 Study Team. Prevention of HIV-1 infection with early antiretroviral therapy. N Engl J Med 2011
  3. Charlebois E.D. et al. The effect of expanded antiretroviral treatment strategies on the HIV epidemic among men who have sex with men in San Francisco Clin Infect Dis 2011;52:1046-9
  4. Das M, Chu P. Santos G.M. et al. Success of test and treat in San Francisco? Reduced time to virologic suppression, decreased community viral load and fewer HIV infections, 2004-2009.18th Conference on Retroviruses and Opportunistic Infections, Boston, February 27-March 2 2011. Abstract 1022.
  5. Serodiscordant couples are when one partner is HIV positive and the other is HIV negative
  6. US DHHS Guidelines for the Use of Antiretroviral Agents in HIV-1 Infected Adults and Adolescents
  7. Michael Carter. Long term use of HIV drugs is safe, does not raise risk of death, study finds, www.aidsmap.com
  8. Grierson J. Koelmeyer R.L. Smith A. Pitts M. Adherence to antiretroviral therapy: factors associated with reported difficulty taking antiretroviral therapy in a national sample of HIV-positive Australians HIV Med 2011 Oct;12 (9):562-9:10.11.11/j1468-1293.2011.00928.xEpub 2011 May 9