CORRESPONDENCE
BRIEWE

HIV prevention and transmission the focus at International AIDS Conference

Ziad El-Khatib^I; Anastasia Pharris^II

^IDivision of International Health (IHCAR) Karolinska Institutet Stockholm Sweden, and AIDS Unit, National Institute for Communicable Diseases, Johannesburg, ziad.el-khatib@ki.se
^IIIHCAR, Karolinska Institutet, Stockholm, Sweden

To the Editor: The XVII International AIDS Conference was held on 3 - 8 August 2008 in Mexico City, with 24 000 implementers, activists, persons living with HIV, researchers and politicians from 194 nations discussing the conference theme: Universal action now!

One of the main messages stressed throughout the conference was that a focus on antiretroviral (ARV) treatment alone has not and will not win the battle against HIV transmission. While increased access to treatment for the millions who need it should be supported and expanded, 2 - 3 persons are newly infected with HIV for each person placed on treatment. And while ARVs alone cannot prevent HIV transmission, neither can a single prevention strategy. UNAIDS director Dr Peter Piot emphasised the need to study the regional context of every HIV epidemic carefully so as to apply the most appropriate combination of strategies for prevention and treatment for the local population. Piot and others stressed the need for 'combination prevention' - an evidence-based mix of context- and epidemic-appropriate prevention strategies applied together to enhance the effectiveness of prevention efforts.

Ross et al.¹ presented a model showing men's age as a risk factor for increased HIV transmission to female partners. The 'take-home' message was that intergenerational sex may be a risk factor, and that sex within the same age group may help to reduce transmission risk.

Powers et al.'s² literature review found that the risk of transmission among the heterosexual population may exceed 1 per 1 000 coital acts, depending on genital ulcers and the presence of circumcision.

Attia et al.³ presented a literature review that found no strong correlation between exposure to ARVs and reduction in transmission between discordant couples, owing to limited data and the unclear effect of other sexually transmitted infections (STIs).

Heneine (on behalf of Parikh et al.⁴) presented a case-control experimental trial of 6 monkeys exposed to SHIV via a tenofovir-based vaginal gel. None of the study group seroconverted, while 86% of a control group that did not receive ARVs seroconverted. In addition to this and other research, there was a resounding call to use HIV funding to support health systems as well as to urgently address human rights violations, gender inequality and stigmatisation, to further support the successful continued scale-up of treatment and combination prevention efforts.

1. Ross D, White R. Using surrogate outcomes for HIV incidence: handle with care. XVII International AIDS Conference, 3 - 8 August 2008, Mexico City. http://www.aids2008.org/Pag/Abstracts.aspx?SID=250&AID=5111 (accessed 19 August 2008).         [ Links ]

2. Powers KA, Poole C, Pettifor AE, Cohen MS. Rethinking the heterosexual infectivity of HIV-1: a systematic review and meta-analysis. Lancet Infect Dis 2008; 8(9): 553-563.         [ Links ]

3. Attia S, Egger M, Low N. Can unsafe sex be safe? Review of sexual transmissibility of HIV-1 according to viral load, HAART, and sexually transmitted infections. XVII International AIDS Conference, 3 - 8 August 2008, Mexico City. http://www.aids2008.org/Pag/Abstracts.aspx?SID=288&AID=15935 (accessed 19 August 2008).         [ Links ]

4. Parikh U, Sharma S, Cong M-E, et al. Complete protection against repeated vaginal SHIV exposures in macaques by a combination emtricitabine and tenofovir topical gel. XVII International AIDS Conference, 3 - 8 August 2008, Mexico City. http://www.aids2008.org/Pag/Abstracts.aspx?SID=288&AID=15936 (accessed 19 August 2008).         [ Links ]