Table 2.
Model scenarios and parameters values for rabies transmission processes, characteristics of the environment and dog population, surveillance and response. Reference scenario parameters and model set up are in bold.
Parameter | Value | Source/Rationale | |
---|---|---|---|
Transmission | Shape and scale of gamma distribution modelling generation interval | Shape 1.46 days; scale 16.1 days | Hampson et al. [23] |
Mean and dispersion parameter of negative binomial distribution modelling R0 | Mean 1.20; k1.33 | Hampson et al. [23]; Townsend et al. [31] | |
Environment and population | Area | 500, 5000, 15,000 km2 | Ambon Maluku, Indonesia ∼775 km2; Bali, Indonesia ∼5600 km2; Bohol, Philippines ∼4100 km2; Nias, Indonesia ∼5100 km2; 3 districts in Eastern Bhutan ∼7000km2; Flores, Indonesia ∼14,300 km2 |
Geometry | Circular, interdigitated | To compare a minimum edge effect versus a large edge effect | |
Human-mediated long distance dog movement | 0, 2, 5% | Estimated for Bali, Indonesia [31] | |
Local movement spatial kernel: mean and dispersion parameter (k) of negative binomial distribution | Mean 0.88 km2; k0.285 | Hampson et al. [23] | |
Annual dog population turnover | 50% | We assume that 50% of dogs vaccinated die one year later, and that the birth and death rates are equivalent | |
Detection and response | Probability of detection | 0.01–0.3, 0.1 | See methods: Detection probabilities |
Response mobilization time | 1, 6, 12 months | Table 1 | |
Lag between detected case and laboratory confirmation | 0, 14 days | Table 1 | |
Time period of cases used to determine reactive vaccination | 1, 6 months | ||
Duration of immunity provided by vaccine | 2 years | Most commercial vaccines provide 1–3 years of protection | |
Vaccination coverage achieved at time and place of vaccination (V) | V = 70%, V∼uniform (35%, 70%),V for 80% of island ∼uniform(35%, 70%) and V for 20% of island ∼uniform(X/2,X) where X∼uniform(0,70%) | 70% target vaccination coverage is recommended by WHO and empirically and theoretically supported [40]. Due to the difficulty of estimating coverage and dog population sizes, coverage achieved is expected to be spatially variable and may often fall below the 70% target. | |
Vaccination strategy | Proactive, prioritise, react w/o repeat, reactive (see Table S1) | Builds on strategies explored in Townsend et al. [31] | |
Cumulative number of cases when start vaccination | 500, 5000 | 5000 is the approx. cumulative number of cases on Bali when mass vaccination started, assuming 10% of cases were confirmed | |
Length of monitoring period | 2 years | OIE and WHO criteria for rabies-free status requires 2 years without indigenously acquired infection [8,21] | |
Months without any detected cases before starting 2-year monitoring period | 2, 6 months | ||
Intervention during monitoring period | No vaccination, proactive vaccination |