HIV is not transmitted under fully suppressive therapy: The Swiss Statement – eight years later

Eight years ago, on January 30th 2008, the Swiss Federal Commission for AIDS-related Issues (“the Commission”, now the Swiss Federal Commission for Sexual Health) published a statement which – in the field of human immunodeficiency virus (HIV) – rapidly received the name “The Swiss statement” [1]. The statement addressed the infectiousness of an HIV-positive person once the virus was stably suppressed for at least 6 months with antiretroviral therapy (ART). Despite the lack of results from large randomised studies, the Commission felt, based on an expert evaluation of HIV transmission risk under therapy, that the risk of HIV transmission in such a situation was negligible. The publication was primarily aimed at Swiss physicians, informing them that it was about time to discuss new data on infectiousness with patients. Problematic differences in prevention messages were already being observed by the Commission: some physicians openly discussed the very low risk of transmission on ART and reassured patients who said they had condomless sex with their steady partner, whereas others told HIV-positive patients under therapy that all condomless sex – even with their HIV-positive partner – was risky. At the time it was clear that ART did, in fact, reduce the likelihood of transmission, but the Commission’s estimate on the magnitude of this risk was neither discussed with patients nor communicated widely. The Commission summarised the epidemiological and biological knowledge known at the time and concluded that the risk of transmission in a differing HIV status partnership where the positive partner was on fully suppressive ART can be considered negligible. The focus of the paper was on how to communicate this information with an affected partnership where one partner was HIV positive.