Evaluating strategies to avoid AIDS: Number of partners vs. use of condoms

Abstract

A probability model based on the best estimates we have today for prevalence and infectivity of Human Immunodeficiency Virus (HIV) has been developed. The model is used to compare the two most widely publicized risk reduction strategies: (1) Reducing the number of partners and (2) Using condoms. The results indicate that under almost all conditions of prevalence and infectivity, consistent and careful condom use is a far more effective method of reducing the risk of HIV infection. The analysis is applied to both high and low prevalence groups. In order to test more rigorously the conclusions, infectivity rates ten times higher than now estimated are examined, and infectivity is estimated on a per partner, as well as a per sexual act basis. Epidemic growth of prevalence is estimated to further check our findings. None of these conditions alters our basic conclusion. It is suggested that there is reluctance to publicize such findings about AIDS because they may be used to support having multiple sexual partners. Nevertheless, it is assumed to be more important to protect ourselves from infection than to sustain norms opposed to multiple sexual partners. Thus, our results may prove extremely useful to those who give advice to people concerning risk reduction strategies.