λj(t) |
Infectious pressure on susceptible farm j at time t
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βij
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Contribution to total infectious pressure from infectious farms. |
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Contribution to total infectious pressure from notified farms. |
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, ,
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Set of susceptible, infected, notified, and removed farms (respectively) at time t. |
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Complete state of the outbreak at time t. |
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h(t) |
Function for modeling disease latency. |
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Ik,
Nk,
Rk
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Infection, notification and removal times of farm k (respectively). |
Notification time is time of laboratory confirmation of FMD; removal time is mean date when the farm is both culled and disposed of. |
ϵ(t) |
Baseline infectious pressure at time t. |
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q(i;ξ) |
Contribution to infectious pressure from characteristics of the infectious farm. |
ξ = {ξ2,ξ3} |
w(j;ζ) |
Contribution to infectious pressure from characteristics of the susceptible farm. |
ζ = {ζ2,ζ3} |
ξ = {ξ2,ξ3} |
Parameters for determining the transmissibility of pigs (2) and sheep (3) relative to cattle. |
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ζ = {ζ2,ζ3} |
Parameters for determining the susceptibility of pigs (2) and sheep (3) relative to cattle. |
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ψ1,ψ2,ψ3
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Exponential terms for calculating infectious pressure from an infectious farm for cattle(1), pigs(2), and sheep(3) respectively. |
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ϕ1,ϕ2,ϕ3
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Exponential terms for calculating infectious pressure for a susceptible farm for cattle (1), pigs (2), and sheep (3) respectively. |
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γ1,γ2
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Multiplicative factor for contribution to infectious pressure from infected (1) and notified (2) farms respectively. |
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δ |
Decay of the transmission rate with distance between premises. |
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ρij
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Euclidean distance between premises i and j. |
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ω |
Exponential parameter associated with the distance kernel. |
Fixed at 1.3 in all outbreaks. |
θt
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Vector of all transmission parameters. |
θ = {ϵ1,ϵ2,γ1,γ2,ξ,ζ,ψ,ϕ,δ,b} |
ck, pk, sk
|
Number of cattle, pigs and sheep (respectively) on premises k. |
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Mean numbers of cattle, pigs, and sheep (respectively) across all farms in the outbreak. |
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di
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Infection to notification time. |
di ~ Gamma (4, b) |
b |
Scale parameter of a gamma distribution governing infection to notification time. |
Set at 0.5. |
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Demographic and event history data observed to time t. |
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Yt
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Demographic and event data of the ongoing epidemic from time t onwards. |
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Joint posterior distribution of model parameters and infection times at time t, conditional on the demographic and event history data. |
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The time immediately before the infection time of the jth premises. |
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P |
Set of all individuals in the population. |
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κ |
The initial infective. |
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a |
Control intervention a. |
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U(Yt|a) |
Expected total number of animals culled (utility function) in the ongoing outbreak from time t onwards under intervention a. |
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Optimal control strategy at time t. |
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