Relationship between adherence to HAART, the per-partnership annualized probability of HIV transmission between serodiscordant agents, and progression to AIDS.

Note: per-partnership transmission values derived from a series of Bernoulli distributions, assuming 10 unprotected sexual acts and 5 syringe sharing events (“trials”) per partnership [97], [128], [129], and per-event transmission probabilities of 0.007, 0.005, and 0.001 for syringe sharing, unprotected sex between men, and unprotected heterosexual sex, respectively [123], [124], [125], [126], [127]. We also assume that the relationship between adherence, viral load, and per-event probability of HIV transmission is linear [132], [133]. The relationship between probability of AIDS progression and adherence is also assumed to be linear [63], [143], [144], [145]. Values shown above are multiplied by a factor of four during the first time step following seroconversion to account for increased probability of HIV transmission during early stage infection [130], [131].