In a statement to doctors, published today in the Bulletin des médecins suisses (Swiss Medical Forum), the Swiss Federal Commission (CFS) on problems relating to AIDS believes it will be able to confirm that HIV-positive people who are on anti-retroviral treatment, and in certain conditions where the effectiveness of the treatment is assured, are not liable to transmit the virus via sexual contact.

This statement is based on data obtained from epidemiological studies carried out among various populations or among couples of different serostatus, which indicates that the use of current powerful treatment reduces the risk of transmission from 60% to 80% among the populations studied.

This data could, in effect, pave the way towards current powerful treatments one day becoming one of a number of tools used in prevention policies at collective level and to limit the spread of the epidemic. Gradually built up since 2000, this data has also allowed the healthcare authorities in the United States to include the reduction of transmission risk among the goals of anti-retroviral treatments in their most recent recommendations, which were issued in December 2007. The data is also to be examined by the group of French experts as part of an update of its recommendations in 2008.

However, it is still too early to say whether this data can be used to extrapolate risk reduction from collective level to individual situations and allow individual recommendations to be made. The observational studies carried out on couples of different serostatus who were receiving treatment involved no more than sixty couples who were followed over limited periods of a maximum of four years. Even though no cases of infection were reported from these studies, the samples are too small to provide sufficient grounds for the exclusion of risk. It would therefore seem premature at this stage to offer individual recommendations on the basis of the existing data. These recommendations must continue to promote the tried-and-tested methods of prevention, namely condom use.

That said, the theory that effective treatment could eliminate the risk of transmission cannot be ruled out. Consequently, further research needs to be done to supplement existing data.

Given the complexity of declared public health objectives, the Conseil national du sida has decided to form a working committee which will examine the existing data to determine its ethical, political and social implications.