HIV could become retro

AP

Protesters parade a banner in front of the stage as US Secretary of State Hillary Clinton speaks at the 19th International Aids Conference held in Washington DC.

THE biggest mega conference yet on HIV/Aids winds down on Friday for the thousands of delegates who descended on Washington DC for the International Aids Conference (Aids 2012) to hear and see what was new in medical science, clinical guidelines, public health policy and, not least, political discourse.

“Turning the tide together” is the official slogan of Aids 2012 – but what are the real issues? What do we know, and what do we need to learn, to make a crucial transition from this unrelenting disaster to some sort of long-term management of HIV infection as a tolerable risk?

In essence there are two sides of the “‘intervention”, or “response”: treatment for those infected, and “prevention” of new infections.

On the treatment side, antiretroviral drugs are one of the astounding successes of modern science. No other comparably serious illness can be so thoroughly and successfully turned back from even a very advanced stage.

Excitement

However, treatment is not necessarily pleasant and must be maintained consistently pretty much for the rest of the patient’s life.

Demonstrators gather in front of the stage and Republican Senator Mike Enzi from Wyoming, seen on a giant video screen during the Aids 2012 conference.

AP

Although cause for concern, the danger of drug resistance developing in response to an occasional missed dose is often overplayed and the process is technically misrepresented in mainstream discourse. On the conventional “prevention” front there are numerous thrusts.

The bruising search for an effective vaccine continues, while antiretroviral drugs for HIV-free – yes, uninfected – high-risk people are investigated.

The latter option seems to prevent transmission effectively when taken regularly, but it is a complex tale.

This so-called “pre-exposure prophylaxis” (or PrEP) has a systemic (pill) and a topical (vaginal/rectal gel) incarnation.

There’s some excitement about recent reports linking a decrease in infection rates to modest “cash transfers”.

These financial hand-outs help vulnerable individuals to manage their risk and to take part in education programmes. In some parts of the world, needle exchange programmes also continue to feature in the mix.

The debate still rages about messaging and “non-biological” interventions. No one knows quite how people decide what risks to take. Although behaviour patterns are always changing, it is unclear how these changes may be positively influenced, if at all, without manipulation and condescension.

With literally thousands of updates on all these threads, the many stories, voices, debates and presentations from the conference could become the proverbial trees that obscure our view of the forest.

Meanwhile, the big shift of recent years in thinking about the social and biological approaches to the epidemic is the realisation that the two broad categories of “treatment” and “prevention” are inextricably linked. Treatment, in fact, is prevention, probably the most impressive form of prevention.

The simple fact has long been known, but has only recently formally been measured: a well-treated HIV-infected patient has a much lower chance of infecting others than an untreated person.

The difference is so huge it is barely possible for conventional clinical trials, following thousands of individuals, to estimate reliably the tiny residual infectiousness of well-treated patients whose virus is under control. (Abstinence and condoms are forms of risk management, and not interventions, but they are certainly effective.)

This holds vast implications for our established approach of treatment, in which patients “qualify” for antiretroviral treatment only if their disease is sufficiently far advanced.

The strategy arises from logistical and financial constraints, and was built around the arguably outdated experience of a previous generation of antiretroviral regimens that had more frequent serious side effects and which were less consistently effective.

Reasons for delaying treatment are evaporating as evidence pours in of the benefits of providing earlier treatment.

A week or two before Aids 2012, the high-impact journal Plos-Medicine (free at www.plosmedicine.org) dedicated a special edition to the impact of earlier treatment, as viewed through the lens of reduced infectiousness of the treated patients.

Although the details vary greatly between various modelled scenarios, under any reasonable assumptions the societal benefits of early treatment are substantial.

A strong treatment policy, delivered by a strong health care system, offers the best hope yet of getting to a favourable tipping point where HIV prevalence may be put into long-term remission. Now it is widely grasped that there is no real divide between treatment and prevention, discourse needs to shift so that the benefit of this deep synergy can be realised.

Many important and complex questions arise. Who comes for testing, and where, and how is it that many people find out they are infected only after years of exposing multiple partners to risky sex?

How does one offer treatment at ever earlier stages of the disease, when the superficially apparent benefit, and hence the motivation to stick to the regimen, are less clear?

How easy is it to pay a huge up-front cost for long-term savings that accrue only beyond the technical planning horizon?

Distribution

How do we administer an audaciously bigger programme of drug distribution and chronic patient care than the impressive one SA has set up in recent years?

Are there effective, and ethical, ways of prioritising treatment access for key groups where the epidemiological impact would be more efficient?

There are, of course, also serious questions about the politics and sociology of making a big, expensive and complex effort to curb the impact of a sexually transmitted infection, and one that disproportionately affects vulnerable populations.

One can only hope these questions will be addressed as discourse matures, and concern for the people and communities affected replaces defensive and moralistic posturing. We will never really know the consequences of planned “interventions” until they unfold.

However, there are enough impressive success stories in the HIV/Aids saga to show optimism is rational, and a unified approach to treatment and prevention offers genuine hope of a future in which HIV really is a retro virus of the past.

* Dr Welte is director of the SA Centre for Epidemiological Modelling and Analysis at Stellenbosch University. Sacema is a Department of Science and Technology/National Research Foundation Centre of Excellence.