Treatment as prevention: what are the next steps?

Keith Alcorn
Published: 20 July 2011
"No one should be forced into treatment," said Eric Fleutelot of Sidaction. ©IAS/Marcus Rose/Worker's Photos

Turning treatment into a prevention tool that can end the HIV pandemic will require not one, but a host of different improvements, in the delivery of health care to achieve its full impact, and will not succeed without full respect for the human rights of people with HIV, the Sixth International AIDS Society conference (IAS 2011) heard this week in Rome.

Following Monday’s comprehensive presentation of results from HPTN 052, the landmark study which showed that early treatment of HIV-positive people reduced the risk of HIV transmission to their partners by 96%, experts have reviewed some of the challenges in translating these results into action.

Professor Julio Montaner of the University of British Columbia, a long-time champion of treatment as prevention, pointed to the first hurdle: the fact that many people with HIV do not know of their infection, and even if they do, many others are either not in regular care or not on treatment.

Only 19% of HIV-infected people in the United States are estimated to have an undetectable viral load, Prof. Montaner noted.

Furthermore, 21% of the population of HIV-infected are unaware of their HIV status, yet they are estimated to account for 54% of onward infections in the United States.

Similarly, in Mozambique, a study that tracked patients from HIV diagnosis through the medical system found that, of 7005 patients who tested positive, 57% were still in care 30 days later. Of these, 77% had a CD4 cell count to determine if they were eligible for antiretroviral treatment (ART). Half of these patients were eligible for ART, and 471 of these 1506 patients actually started ART within 30 days. Of the original 7005 patients, just 317 made it onto ART and were then adherent for at least six months.

Getting all parts of the process, from the offering of an HIV test through referral to care, starting treatment and ensuring long-term adherence to treatment, will be critical for ensuring that the proportion of people with suppressed viral load is as high as possible.

Couples first?

Some voices at the conference are beginning to say that it is unethical not to provide treatment for anyone who is part of a serodiscordant couple.

So should the focus be on population-wide treatment, or should treatment target couples?

Wafaa El-Sadr of Columbia University’s International Center for AIDS Care and Treatment Programs (ICAP), which provides treatment to over one million people in 21 countries, pointed out that individuals with HIV who form part of a serodiscordant couple may form a very small part of the total population of people with HIV in some of the countries she works in.

In Lesotho, for example, 15% of couples contained one HIV-positive partner, according to Demographic and Health surveys (see systematic review by Eyawo et al.), but in Rwanda, only 2.1% of couples tested were serodiscordant. Although high-burden countries are likely to have the biggest proportion of serodiscordant couples, this number is likely to be dwarfed by the number of people who do not know their HIV status.

She argued that any decision made at country level will be highly dependent on population size and on the proportion of diagnosed HIV-positive people in serodiscordant couples. Modelling work by Wafaa El-Sadr and Sally Blower shows that high ART coverage in serodiscordant couples (>70%) could have a substantial impact in Malawi and Lesotho, but a negligible impact in Ghana and Rwanda.

“WHO is very clear that people who are sickest should have first priority for antiretroviral therapy”, Craig McClure

Craig McClure, co-director of Treatment 2.0 activities at the World Health Organization, said: “WHO is very clear that people who are sickest should have first priority for antiretroviral therapy.”

“All my patients are in a serodiscordant couple at some point,” said Professor Montaner. His comment underlines the artificial nature of the distinction being made if serodiscordant couples are chosen as the priority group on the basis of applying strict criteria that do not extrapolate beyond the population studied in randomised trials (these trials are the gold standard on which WHO must base its guidance).

In addition, any strict definition of a couple is likely to ignore the fact that many people with HIV have multiple partners, are unmarried or have several regular partners, pointed out Professor Helen Rees of Wits Reproductive Health and HIV Institute.

The World Health Organization will be convening a high-level panel to review the role of antiretrovirals for treatment and for prevention over the next twelve months, with a view to simplifying and integrating guidance into one document, said Craig McClure.

Human rights

Eric Fleutelot, director of international programmes for Sidaction, a French HIV organisation, warned that thinking about treatment as prevention needs to put people with HIV at the centre of any strategy.

“It is a revolution in prevention, but is it going to be like the French revolution, in which a new elite of experts and public health people become more powerful, or is it going to be a democratic revolution in which people with HIV are freed from the fear of passing the virus to their partners?”

“Treatment as prevention offers a wonderful opportunity to discuss about the sexuality of people living with HIV within the context of positive health, rights and dignity. HIV remains a disease that is highly difficult to disclose to family and friends, and highly prevalent among discriminated and marginalised people.”

He said that community organisations recommend an immediate review of counselling and medical services for serodiscordant couples and pregnant HIV-positive women, and called for more research to look at the impact of treatment as prevention on sexual behaviour, and on the criminalisation of HIV transmission.

He also called for more research to determine the extent to which transmissions that take place despite treatment are due to sexually transmitted infections.

Finally, he noted, “We need to ensure that early treatment has a clear benefit [for the person who is taking it] and the results of the START trial will be very helpful.”

“Every individual with HIV should decide for themselves when and how to start treatment,” Eric Fleutolet

The START trial is a large randomised study which is comparing starting treatment at a CD4 count of 350 – the current WHO recommendation – with starting treatment at a CD4 count above 500, and is expected to report results by 2015.

Waafa El-Sadr commented: “The treatment benefit of HPTN 052 is less compelling than the prevention benefit.”

“Every individual with HIV should decide for themselves when and how to start treatment,” said Fleutelot. “No one should be forced or coerced into treatment primarily for the benefit of the public health rather than the health or the well-being of the individual.”

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