Table 1.
Overview of assumptions and pre-set parameters
| Parameters | Valuea | Source |
|---|---|---|
| Human birth rate (per 1000 capita, αH) | 21 (Indian crude birth rate in 2011) | [32] |
| Human mortality rate (μH) | Age-dependent (Indian mortality rates in 2011) | [33] |
| Average duration of late recovered stage (years, 1/ρRHC) | 2 or 5 | Pre-set |
| Average duration of symptomatic untreated stage (days, 1/ρIHS) | 30 (fitting) and 45 (predicting) | Unpublished data |
| Average duration of symptomatic treatment 1 (days, 1/ρIHT1) | 30 (fitting) and 2.5 (predicting) | [34] |
| Average duration of symptomatic treatment 2 (days, 1/ρIHT2) | 30 (fitting) and 10 (predicting) | [35] |
| Average duration of putatively recovered stage (months, 1/ρIHT) | 21 | [36] |
| Average duration of PKDL (years, 1/ρIHL) | 5 (models 1 and 2) and 15 (model 3) | Expert opinion (EH and MB) |
| Infectiveness of symptomatic untreated cases (p IHS) | 1.0 | Reference value |
| Infectiveness of patients under treatment 1 and 2 (p IHT1, p IHT2) | 0.5 | Expert opinion (EH and MB) |
| Infectiveness of PKDL cases (p IHL) | 0.5 (models 1 and 2 only; estimated for model 3) | Expert opinion (EH and MB) |
| Fraction of untreated symptomatic cases that spontaneously, putatively recover (f p) | 0.03 | [25] |
| Excess mortality rate among untreated symptomatic cases (per day, μK) | 1/150 | Assumption |
| Excess mortality rate among treated symptomatic cases (per day, μKT) | 1/150 + 1/600 = 1/120 (fitting) and 1/150 (predicting) | [34, 35] |
| Fraction of failed first-line treatments (f F) | 0.05 | [37] |
| Fraction of putatively recovered cases that develop PKDL (f L) | 0.05 (set such that models 1 and 2 predicted a prevalence of PKDL between 4.4 and 7.8 per 10,000 capita in India) | [10, 38] |
| Average life expectancy of the sandfly (days, 1/μF) | 14 | [39] |
| Average duration of incubation period in sandflies (days, 1/ρEF) | 5 | [62] |
| Sandfly biting rate (per day, β) | 1/4 | [63] |
| Transmission probability sandfly to human (p H) | 1.0b | Reference value |
The parameter values listed here are the same for all three models and their sub-variants, unless indicated otherwise
aParameter values marked with “fitting” only apply to the KalaNet study setting and were therefore only used when fitting the models to the KalaNet data; related to this, different parameter values were used when predicting the impact of IRS (indicated by “predicting”)
bThe probability that a susceptible person becomes infected when bitten by an infectious sandfly is assumed to be 1; potential overestimation is compensated by the estimated sandfly density per human