London School of Hygiene & Tropical Medicine

A team of researchers led by Professor Richard Hayes at the London School of Hygiene & Tropical Medicine has been awarded $37 million to test an innovative combination of strategies to prevent HIV in African countries.

The project, called PopART, will test the impact of a combination prevention strategy that combines community-wide house-to-house voluntary testing for HIV, offer of medical circumcision to men who test HIV-negative, and offer of immediate initiation of antiretroviral therapy (ART) for all those testing HIV-positive.

Researchers from LSHTM and partners including Imperial College London, the Zambia AIDS Related Tuberculosis Project (ZAMBART) and the Desmond Tutu TB Centre (DTTC), Stellenbosch University, South Africa will work closely on this trial with colleagues from the HIV Prevention Trials Network (HPTN).

Part of the HPTN, the study (designated HPTN 071) has been funded jointly by organisations including the National Institute of Allergy and Infectious Diseases (NIAID),the National Institute of Mental Health (NIMH), the Office of the United States Global AIDS Coordinator (OGAC) and the Bill and Melinda Gates Foundation (BMGF).

An estimated 33 million people worldwide are living with HIV; with 2.5 new infections for every HIV-positive patient commencing ART, current approaches to treatment and prevention are struggling to contain the spread of the infection.

Unless the incidence of HIV can be steeply reduced, forecasts show a continuously growing number of HIV-infected individuals so that by 2030 about $35 billion per year will be needed to deliver ART to HIV-positive patients in these resource-limited settings. Combination prevention approaches like PopART may be initially more expensive than current approaches, but estimates suggest that if HIV incidence is not reduced significantly, the financial impact of an ever increasing number of patients in need of treatment and hospitalisation will be far greater.

The new project builds on two previous HPTN trials. Project Accept (HPTN 043) found that adding community mobilization and support services to a mobile HIV counselling and testing programme can improve rates of testing in rural communities. HPTN 052 was the first randomized trial to show that treating an HIV-infected individual with ART reduces the risk of sexual transmission of HIV to an uninfected partner.

Mathematical modelling has shown that the PopART intervention should lead to a steep reduction in new HIV infections. A rigorously designed trial is now needed to test whether such interventions can be effectively implemented in resource-poor settings in Africa, and to measure the actual impact on HIV at population level.

Starting in 2012, the trial will be carried out in 24 communities in Zambia and South Africa, with a total population of over 1 million. Eight communities will receive the full PopART intervention while eight control communities will receive current standard of care. The remaining eight communities will receive an intermediate intervention which includes all the components of PopART except that ART will be given according to current national guidelines. This three-arm design will allow the trial to measure the extra effect of treating patients immediately rather than waiting until their immune function has deteriorated. A total of 60,000 adults from the communities will be followed up for 2 years to measure the impact of the interventions on new HIV infections.

Data from the trial will be combined with cost data and projections from mathematical models to estimate the cost effectiveness of the intervention and alternative approaches.

Richard Hayes, Professor of Epidemiology and International Health at LSHTM, says: "PopART is designed as a universal intervention offered to the entire community. We hope this will prevent stigmatisation of infected individuals and reduce the need for specially targeted interventions for specific risk groups. There is a strong rationale for the PopART approach, but we need a rigorously conducted study to determine how well the strategy can be delivered in practice, and what impact it has at population level."

Professor Peter Piot, the School's Director and former Executive Director of UNAIDS, says: "I am delighted that this award has been made as it will enable the promising idea of combination prevention strategy to be tested on a large scale. This is one of the most important questions for AIDS research and policy today."