TABLE.
Model Parameters
| Symbol | Values Explored | Description |
|---|---|---|
| N0 | 10,000 | Initial population size |
| c | 0.1, 0.1666, 0.3333, 0.5, 1.1111 | Mean no. sex acts per partnership per day |
| βa i | (β1, β2, β3) = (0.03604, 0.00084, 0.00421) | Transmission probability per act during stage i |
| γi | (γ1, γ2, γ3) = (1/49, 1/2570, 1/365) | Stage-progression probability from stage i to the next per day |
| σ | 0, 0.0001, 0.001, 0.01, 0.1, 1 | Partnership dissolution probability per day |
| ξ | 0, 0.3, 0.7, 1 | The ratio of partnership formation probabilities comparing a partnership between 2 individuals of whom at least one is not single to a partnership between 2 single individuals |
| μ | 1/9120 | Probability an individual leaves the sexually active population per day |
| N | 0.9, 1, 1.5, 3, 5 | Population-averaged no. partners per person |
a
β1 and β2 were based on new analyses6 of the Rakai study.7 To compute β3, we used the data about the last 2 follow-up periods of the “late-stage index partner” cohort from the Rakai study.7 There were total 66 discordant couples and transmissions occurred in 17 couples. Average no. sex acts was 70.7 per couple. Thus, β3 = 1 − (1 − NT/N)1/c for N = 66, NT = 17, c = 70.7.