[For the association Warning, April 13th 2012: http://www.thewarning.info/spip.php?article339]
On March 20th, James Wilton, the Biomedical Science of HIV Prevention Project Coordinator, of Canada’s gateway to information about HIV/AIDS (CATIE), gave an extremely problematic interview for the online journal Positive Lite (http://positivelite.com/content/news/news-sections/features-and-interviews/item/understanding-risk-a-conversation). There is indeed a result of inaccuracies and outdated arguments.
Thus, Mr. Wilton explains, as one might read and hear the following statements of Professor Hirschel in 2008, that the TasP (treatment as prevention) cannot be extrapolated to gay couples because: 1. Sodomy is not vaginal intercourse and appears to be a more contaminant practice, especially for the receptive partner 2. The seminal (sperm) viral load (VL) cannot be correlated with plasma (blood) viral load, especially in the presence of other STIs. It would be good if Mr. Wilson updates its biomedical knowledge  and offers us a more nuanced approach.
First, scientists are not unanimous on the greater infectivity of sodomy in relation to vaginal intercourse . On the other hand, it could never lead, for demographic reasons, randomized survey to show a similar efficacy between TasP among gays and among straights. Except that we know empirically for a while that it works: in doctors’ offices, the TasP is used effectively among serodifferent gay couples as an alternative to condoms. What should be added to common sense and the (bio)logic: no pathogen = no contamination .
So when the VLs are undetectables, what’s the problem? Cause Mr. Wilson explains untruths about differential viral loads, which is another argument against the extrapolation of the TasP for serodifferent gay couples. But it is now widely demonstrated: the seminal VL is very well correlated with plasmatic VL. Although it falls more slowly than plasmatic VL; so you have to explain sperm fetishists to wait a year to resume undetectable plasmatic VL before eating their poz husbands’ juice. As for the rectal VL, it is very well correlated with the plasmatic VL and does not increase in the presence of STIs in the rectum .
Certainly, the presence of another STI can raise the seminal VL, but the Swiss statements and the HTPN 052 study  are based on very clear criterias: undetectable plasmatic VL for at least 6 months, good adherence on treatments and, no presence of STI. So use the argument of STI to challenge the validity of TasP among serodifferent and stable gay couples is at best irrelevant and at worst homophobic, in any way misleading!
Finally, Mr. Wilson uses the old behaviorist argument: “A major concern is that people may switch from the correct and consistent use of condoms to a strategy that is less protective”. This is exactly the same that was used during the implementation of post-exposure prophylaxis (PEP) for all, more than 10 years ago: the PEP would “cause a slackening of prevention…” On the contrary, it seems that the experience of PEP has usually the effect of encouraging those concerned to maintain a more consistent condom use. And anyway, TasP does not protect less than condom, on the contrary, since studies of condom use in heterosexual serodifferent couples observe an average reduction of transmission of about 80%  then HPTN 052 study that has found its next lower seroconversion of 96% when treating the person with HIV .
Better yet, published in 2010 in the Lancet, the study by Donnel and his team had shown a reduction in transmission of 92% in discordant couples whose partners are HIV positive receiving treatment . But looking closer, you realize that the only case of transmission (which led to this figure of 92%) occurred in very specific conditions: the negative partner was infected in a period of one to two months before her partner starting treatment. It could therefore have been infected before the initiation of treatment of her partner, or even before viral replication stops. This is clearly outside the Swiss criteria (having maintained an undetectable viral load for at least 6 months). Excluding this case, the Donnel study shows therefore 100% efficiency of TasP. Ditto for the HPTN 052 study whose data have been presented at IAS Conference in Rome (Summer 2011): a single case of transmission, still under conditions outside of the Swiss criteria (the transmission took place within an interval of 3 months after starting treatment of the partner). Therefore did not allow the treatment to act on the viral replication and the virus presence in fluids .
These are two studies that show no evidence there is a residual risk and also that the treatment actually prevents HIV transmission to the partner when the minimum conditions are met . It is now time for prevention organizations and Canadian Public Health to set up, as in Germany , France , Switzerland , the UK and even recently in the U.S. , combined prevention , articulated on revised guidance, innovative solutions  and not on speculation! This wait-Canada has become incomprehensible.
Incomprehensible even though contamination among young Canadian gays are increasing!
Incomprehensible because where health authorities have renewed prevention policies by promoting a truly holistic approach of harm risk reduction in sexuality (TasP, seroadaptation, Test & Treat, negotiated safety, community viral load) in a complementary condom promotion, the number of contamination has lowered (San Francisco , Switzerland ).
Incomprehensible because the limits of prevention based on the unique use of condoms are widely demonstrated for years, and the necessary renewal of the preventive paradigm increasingly urgent to implement.
 http://jid.oxfordjournals.org/content/204/5/761.abstract & http://www.aidsmap.com/Plasma-and-rectal-viral-load-correlated-in-HIV-positive-gay-men-supports-use-of-treatment-as-prevention/page/2063383 & http://www.seronet.info/article/tasp-plasma-et-rectum-ca-correle-chez-les-gays-meme-avec-des-ist-42140
 “Because each of us has a different life and sexuality all its own, it is to have at our disposal many tools as possible for our own prejudices that we should, at the right time! Combined prevention is to use one or more means of prevention according to our possibilities, our practices, our desires and those of our (or ours) partner(s). Able to talk about our sexuality and our health with our partner, our lovers, our friends, with medical professionals caring or activists can take stock of our practices and to get answers to our questions … So, to not be alone with our doubts, our questions, anxieties … let’s talk!”: http://www.aides.org/evenement/PREVS-et-vive-le-sexe-1166