Preventing the heterosexual spread of AIDS: what is the best advice if compliance is taken into account?

It has been recently advocated that avoiding partners who may be at high risk of carrying HIV provides 5000-fold better protection against HIV infection than usage of condoms [1]. In this paper, it is demonstrated that this guideline is largely based on unrealistic assumptions. If the sensitivity of identifying high-risk partners, realistic estimates of the efficiency of mechanical and chemical barrier methods, and the compliance in following either strategy are taken into account, use of condoms and/or suppositories containing nonoxynol-9 might be more effective than the attempt to avoid high-risk partners. Thus, both barrier methods should be strongly recommended for casual sexual heterosexual contacts.