Table 1.
Parameters of the model and initial values.
| Parameter | Value |
|---|---|
| Demographic and behavioral | |
| Initial overall population size | 1 × 105 individuals |
| Initial number of infected | 2 × 103 individuals |
| Minimum relationship duration | 0.1 years |
| Maximum relationship duration | 5.0 years |
| Subgroups defined by relationship duration* | Original: <0.5, 0.5–2.5, >2.5 years |
| Alternate: 1 group (no subgroups) | |
| Probability of sexual contact, in each group* | Original: 1.0, 0.05, 0.03 per day |
| Alternate: 1.0 | |
| Mean degree* | Original: 0.9 |
| Alternate: 0.7 | |
| Virologic | |
| Viral load at time zero | 10 copies/ml |
| Viral load at peak viremia | 1.0 × 107 copies/ml (Schacker et al. 1998; Pilcher et al. 2004) |
| Time to peak viremia | 21 days (Schacker et al. 1998; Pilcher et al. 2004) |
| Total time of acute infection | 91 days (Pilcher et al. 2004) |
| Viral load progression rate, natural log | 0.05 per year (Geskus et al. 2007) |
| Viral load at AIDS (CD4<200) | 5.0 × 106 copies/ml (Geskus et al. 2007) |
| SPVL | |
| Variance of log10 SPVL | 0.7 (Korenromp et al. 2009) |
| Heritability of SPVL across transmissions (h2) | 0.36 (Fraser et al. 2014) |
| Mutational variance | 0.2 |
| Transmission | |
| Maximum transmission rate | 0.005/day (Fraser et al. 2007; Shirreff et al. 2011) |
| Viral load at 0.5 max transmission rate | 13,938 copies/ml (Fraser et al. 2007; Shirreff et al. 2011) |
| Hill coefficient, transmission function | 1.02 (Fraser et al. 2007; Shirreff et al. 2011) |
| Shape parameter, transmission function | 3.46 (Fraser et al. 2007; Shirreff et al. 2011) |
| Disease progression | |
| See Cori et al. for CD4 wait time matrix stratified by SPVL (Cori et al. 2015) | |
| ART | |
| Time to initiation after becoming eligible by CD4 | 1 year(Eaton et al. 2012) |
| Viral load after ART initiation | 50 copies/ml |
Parameters with an asterisk (*) had different values between the original and alternate model calibrations.