Table 1.
Model input parameters to estimate impact of combination prevention package scale-up in intervention communities versus standard of care communities over 3 years
| Parameters common to both communities: | |
|---|---|
| Parameter | Value |
| Duration of Partnerships | See Figure 2 |
| Degree Distribution | Negative Binomial (r = 5, p = .7, cutoff = 7) |
| Probability of Transmission per 100 person-years | |
| Viral Load < 400 copies/ml | 1 |
| Viral Load 400 – 3499 copies/ml | 4.8 |
| Viral Load 3500 – 9999 copies/ml | 12 |
| Viral Load 10, 000 – 49, 999 copies/ml | 14 |
| Viral Load 50000+ copies/ml | 23 |
| HIV prevalence | 24.8% |
| Percent on treatment at time 0 among those eligible (CD4 < 350 cells/mm3) | 60.9% |
| Reduction in transmission risk from knowledge of serostatus | 30% |
| Duration of high viral load after infection | Estimates from the Botswana/Durban cohort |
| Rate of CD4 decline | Estimates from the Botswana/Durban cohort |
| Reduction in acquisition risk from circumcision | 60% |
| Reduction in trans. risk for condoms | 85% |
| Percent of individuals using condoms | 40% |
| Parameters differ by treatment arm: | ||||||
|---|---|---|---|---|---|---|
| Standard of Care Arm | Intervention Arm | |||||
| HTC1 | MC2 | Linkage to Care | HTC1 | MC2 | Linkage to Care | |
| Baseline | 37%3 | 12.7%3 | 80% | 37% | 12.7%3 | 80% |
| End of Year1 | 37% | 31.4%4 | 80% | 81% | 46.4% | 90% |
| End of Year2 | 45% | 50.0%4 | 80% | 90%5 | 80%6 | 90% |
| End of Year3 | 52% | 60.0%4 | 80% | 90%5 | 80%6 | 90% |
HIV testing and counseling.
Male circumcision.
The Botswana HIV/AIDS impact survey III results, 2008.
Male circumcision campaigns in standard of care communities will be ongoing, and may reach 60% coverage by the end of year 3 post randomization, if Ministry of Health targets are met.
Assume that the project aims to increase HIV testing and counseling coverage to ≥90% in intervention communities by the end of the second study year and maintain this thereafter.
Assume that the project aims to reach 80% male circumcision coverage in intervention communities by the end of the second study year and maintain this thereafter.