HIV research receives top recognition as a 2007 "must-read"

Imperial College researchers' work shortlisted for The Lancet's Paper of the Year award <em> - News - 15 February 2008</em>

By Laura Gallagher
Friday 15 February 2008

A paper by Imperial College researchers has been selected as a "must-read" of 2007 by the medical journal The Lancet.

The paper is one of a dozen research papers shortlisted for The Lancet's Paper of the Year award. The nominated papers were selected for making the greatest potential contribution to clinical research by members of The Lancet’s International Advisory Board.

William Summerskill, Senior Editor of the Lancet, described the exercise as "an opportunity to celebrate research and researchers, enriched by the passion of colleagues about the papers that excited them most in the past 12 months."

Imperial's paper, published in October 2007 in the Proceedings of the National Academy of Sciences journal, was authored by Department of Infectious Disease Epidemiology researchers Dr Christophe Fraser, Dr Deirdre Hollingsworth, Professor Frank de Wolf and Dr William P. Hanage.

Entitled "Variation in HIV-1 set-point viral load: Epidemiological analysis and an evolutionary hypothesis", the paper revealed that people with medium levels of HIV in their blood are likely to contribute most to the spread of the virus.

It found that those with a high viral load are the most infectious group, but have only limited time to infect others, because they generally progress to AIDS quite quickly. Viral load - a count of how many viral particles are in a person's blood – varies hugely between individuals. The higher the viral load, the more infectious a person is but the shorter their life expectancy. As a result, the study found, those with a high viral load do not contribute the most in the long run to the spread of HIV.

Those with a medium viral load are moderately infectious but remain asymptomatic for a period of about six to eight years before progressing to the symptoms of AIDS. This means they can be unaware that they have HIV for a long period of time, during which they can transmit the virus to a number of different sexual partners, and hence contribute most to the epidemic.

Those with a medium viral load form the largest, most common group amongst those not receiving treatment. One reason for this could be that the virus has evolved to achieve the optimal balance between infectiousness and virulence, in order to maximise its chances of getting passed on. The researchers now plan to investigate this hypothesis.

Dr Christophe Fraser, corresponding author on the paper, said: "I was delighted and very surprised to see us on the final shortlist of papers, particularly as the most important part of this study is about developing ideas and proposing a new hypothesis. It was perhaps a surprising choice for a clinical journal.

"I guess the nominating people recognised that this is an original perspective on an important topic, and that while we still have work to do to test the hypothesis, that the potential public health impact would be important. Gaining some extra visibility for this study will help motivate us in the painstaking process of testing the evidence on the evolution of HIV which we are currently engaged in."

Professor Brian Spratt, Head of the Department of Infectious Disease Epidemiology, added: "Considering the huge number of papers published each year on medicine it is a great achievement for Christophe Fraser and his colleagues in the department to have their PNAS paper singled out as among the ten best papers of 2007. I think what probably grabbed the attention of the Lancet panel was that the paper says something about HIV transmission that, like many original ideas, is obvious once it has been pointed out."

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