Over the past three decades there has been a wealth of operational research into effectively and effciently combating human immunodeficiency virus (HIV). These interventions have had varying results. Condoms, for example, have been shown to decrease the probability of transmission per sexual act (PTSA) by 95%, but they tend to be used inconsistently. Male circumcision has been shown to reduce the PTSA by 50%, but provides consistent partial protection by design. Antiretroviral therapy (ART) is a medical treatment that slows the reproduction of HIV. ART has been associated with 96% reduction in PTSA, and has been shown to prolong the life of an infected individual. However, it is diffcult to determine how to optimally distribute limited HIV prevention
Our simulations suggests that the impact of TasP interventions is complex and that long-term outcomes need to be considered according to specific objectives. Expanding ART to a larger proportion of the subgroups with higher CD4 levels or in serodiscordant relationships may have the most favourable incremental cost-effectiveness ratios.