Swiss Experts Claim HIV Patients with Undetectable Viral Load Who Adhere to Treatment Cannot Transmit the Virus to HIV Negative Partners

Several HIV/AIDS advocacy groups and scientists have expressed dismay and disbelief about the findings of a report from The Swiss AIDS Commission, based on several studies, that individuals using anti-HIV drugs cannot transmit HIV infection to their sex partners, if they have undetectable viral loads (< 40 copies/ml) for at least six months and if they remain adherent to their treatment regimens.

The statement is published in this week's Bulletin of Swiss Medicine (Bulletin des médecins suisses). The statement also discusses the implications of this finding for doctors, for HIV-positive people, for HIV prevention, and for the legal system.

The statement, on behalf of the Swiss Federal Commission for HIV/AIDS was co-authored by four of Switzerland's foremost HIV experts: Professor Pietro Vernazza, of the Cantonal Hospital in St. Gallen, and President of the Swiss Federal Commission for HIV/AIDS; Professor Bernard Hirschel from Geneva University Hospital; Dr. Enos Bernasconi of the Lugano Regional Hospital; and Dr. Markus Flepp, president of the Swiss Federal Office of Public Health's Sub-committee on the clincal and therapeutic aspects of HIV/AIDS.

The statement's headline statement says that "After review of the medical literature and extensive discussion," the Swiss Federal Commission for HIV/AIDS resolves that, "An HIV-infected person on antiretroviral therapy with completely suppressed viremia ("effective ART") is not sexually infectious, i.e. cannot transmit HIV through sexual contact."

In their statement , the authors noted the significant legal ramificationss of the report authors: "The Commission thinks that unprotected sex between a positive person on antiretroviral treatment and without an sexually transmitted infection (STI), and an HIV-negative person, does not comply with the criteria for an "attempt at propagation of a dangerous disease" according to section 231 of the Swiss penal code nor for "an attempt to engender grievous bodily harm" according to section122, 123 or 125.

One of the studies cited in the Swiss report was conducted in Spain between 1990 and 2003 among 393 heterosexual couples with one being HIV-positive. The study authors concluded that none of the HIV negative partners became infected due to unprotected sex with an HIV positive individual using anti-HIV drugs, according to AFP/Yahoo! News.

A second, Brazilian study concluded that among 43 of 93 couples with an HIV positive partner, six people became infected with HIV. In these six cases, all the new infections occurred due to the HIV positive partners not adhering to their treatment regimens, according to the study findings.

AFP/Yahoo! Newsreports that the other two studies, one in Uganda and one among pregnant women, yielded similar results, according to Dr. Bernard Hirschel, a co-author of the Swiss report and an HIV/AIDS specialist at University Hospital in Geneva.

Reaction of Some HIV Experts and Patient Advocates

Several HIV/AIDS advocacy groups and scientists expressed skepticism about the results of the studies, and noted that the studies were performed among heterosexuals practicing unprotected vaginal intercourse and did not include data on men-having-sex-with-men who engage in unprotected anal sex, according to AFP/Yahoo! News.

"Not only is [the Swiss proposal] dangerous, it's misleading and it is not considering the implications of the biological facts involved with HIV transmission," said Dr. Jay Levy, director of the Laboratory for Tumor and AIDS Virus Research at the University of California in San Francisco and one of the co-discoverers of HIV.

"There is still some concern that you can never guarantee that somebody will not be infectious, and the evidence I have to say is not conclusive," said Charlie Gilks, director of AIDS treatment and prevention at the World Health Organization (WHO). UNAIDS and the WHO said condoms were vital for a comprehensive HIV prevention package, along with fewer sexual partners, non-penetrative sex, and early and effective treatment for other sexually transmitted infections, according to a Reuters report.

"We are not going to be changing in any way our very clear recommendations that people on treatment continue to practice safer sex, including protected sex with a condom, in any relationship," he added.

"In any case, of the 2 million people worldwide now receiving HIV treatment, only a very small number receive medical care comparable to that in Switzerland," Gilks said.

Roger Peabody of the Terrence Higgins Trust in London said the "real thing" missing from the report was information about "anal sex and getting a new" STI. "We don't feel the scientific evidence is conclusive, and there are some key issues that are not covered" in the report, Peabody said.

The French HIV/AIDS advocacy group Act Up said that only a small number of
HIV-positive people would be affected by the findings and added that 40% of HIV positive people taking antiretrovirals still carry the virus despite treatment adherence.

France's National AIDS Council said the findings are not conclusive enough to apply to all HIV positive people who follow their treatment regimens. Dr. Hirschel said that although the report "can provoke certain fears," the information is "credible" and "relies on proven and certain facts" and "should be made known," according to AFP/Yahoo! News.

2/5/08

Sources

P Vernazza et al. Les personnes séropositives ne souffrant d'aucune autre MST et suivant un traitment antirétroviral efficace ne transmettent pas le VIH par voie sexuelle. Bulletin des médecins suisses 89 (5), 2008.

F Jordans. Swiss change safe sex message on HIV. AP/Yahoo! News. January 31, 2008.

Reuters News. HIV therapy does not eliminate transmission risk-WHO. February 1, 2008.