Microbicides 2004 Microbicides 200428-31 March 2004, Hilton London MetropoleThe conference42 million men, women and children worldwide were living with HIV by the end of December 2002 (source: UNAIDS), including five million newly-infected during that year alone. Another 45 million people will become infected between 2002 and 2010, unless the current transmission rates can be vastly reduced. Of the 42 million, 29.4 million live in sub-Saharan Africa and 58% of them are women. Not only are women more susceptible to HIV infection, many are powerless to insist on the use of condoms or other methods of protecting themselves. In this context, and with the knowledge that an effective HIV vaccine is unlikely to be available for several years, the need for an effective topical microbicide grows ever more urgent. 2004 should prove to be a landmark year in the field of microbicide development as the first Phase III trials of novel products are due to start – the next step along the road to making a microbicide available to the millions worldwide in desperate need of protection.The aims of the Microbicides 2004 conference are to:Report novel or innovative work in the microbicides fieldProvide updates on recent microbicides research, divided into three tracks: basic science, clinical science, and behavioural science (including public health and the microbicide marketplace)Provide a forum for the discussion of new developments in microbicide research including ethical, clinical, behavioural and methodological issuesPresent opportunities for knowledge-sharing between microbicide researchers, public-health workers and advocacy organisations.There will be an opening ceremony on the evening of Sunday 28 March at which politicians, policy makers and the international media are expected. The conference will run for a full three days, each of which will contain:Scientific overviews and presentations with plenary sessions, invited lecturers and presentations of original researchWorkshops to review issues unique to microbicides such as trial design and outcome measures, and ethical issues in the clinical trials of microbicidesPoster sessions. Focus on LondonFollowing the successful Microbicides conferences in Washington in 2000 and Antwerp in 2002, March 2004 sees the focus move to London.The venue is the Hilton Metropole Hotel, two minutes by taxi from Paddington station and the Heathrow Express, with a journey time from the airport of 15 minutes. The hotel is in walking distance of Hyde Park and London’s main shopping streets, and close to Imperial College. Accommodation will be available at the venue and other hotels in the vicinity.London in March offers a variety of diversions for out-of-conference relaxation, including sight-seeing and shopping; the arts and the theatre; and pubs, clubs and restaurants to suit every taste. Conference staff will be on hand to help delegates plan their spare time.To book your place or find out more information, e-mail info@microbicides2004.org.uk or telephone the Event Office on +44 (0) 20 7720 4411
Oral: invited speaker Oral: Track A Oral: Track B Oral: Track C Poster: Track A Poster: Track B Poster: Track C Abstract only Authors

02679 HIV-1 RNA IN RECTAL MUCOSA SECRETIONS AND SEMINAL PLASMA; CONSIDERATIONS FOR MICROBICIDE EFFICACY

Zuckerman, Richard*
Whittington W*, Celum, C*, Collis, T*, Lucchetti, A,** Sanchez, J**, Hughes, J*, Sanchez, Jl***, Coombs, R*
*University of Washington, Seattle Wa., **Impacta, Lima, Peru, ***Walter Reed Army Institute of Research, Rockville, Md

Objective: High levels of HIV in rectal secretions and semen likely increase the risk of HIV transmission. An understanding of the natural variability of mucosal HIV shedding and the factors that influence HIV levels in anogenital secretions is important for studying microbicide efficacy at the mucosal surface. Methods: HIV-infected men who have sex with men (MSM) made 2-3 visits over 4 wks at clinics in Seattle, WA USA and Lima, Peru to assess rectal, seminal and plasma HIV RNA levels. Mixed effects models were used to estimate the effect of factors on HIV shedding from the two mucosal sites. Results: Twenty-seven (42%) of 64 men were taking antiretrovirals (ART) and regardless of ART use, median HIV RNA levels were higher in rectal secretions (4.96 log10 c/mL) than in blood (4.24 log10 c/mL) or seminal plasma (3.55 log10 c/mL, P<0.05, each comparison). ART was associated with 1.3 log10 reduction in rectal RNA in a model without plasma RNA; with plasma RNA in the model, ART was not significantly associated with rectal HIV RNA levels. With and without plasma RNA in models, ART accounted for >1 log10 decrease in seminal HIV RNA level. Thus, controlling for plasma HIV, ART had an independent effect on seminal but not rectal HIV levels. Additionally, levels of HIV in rectal secretions were 0.5 log10 higher in Peruvian than in Seattle participants after controlling for ART use, CD4 count and plasma VL, and could not be explained by the examination findings or behavioral factors that we assessed. Conclusions: Factors that affect HIV levels in rectal secretions and seminal plasma have implications for understanding the risk of transmission associated with different sexual exposures with HIV-infected partners. Studies of microbicide efficacy need to account for highly variable mucosal HIV shedding in MSM.

Richard A. Zuckerman
Seattle HPTU; 901 Boren Avenue, Suite 1300; Seattle, WA 98104, USA
(Telephone) (206) 521-1578 (Fax) (206) 521-5828 (E-mail) zuckermn@u.washington.edu