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Table 1 Parameters in a stochastic SIS E VTEC O157 model

From: Spatio-temporal modelling of verotoxigenic Escherichia coli O157 in cattle in Sweden: exploring options for control

Parameter Description (unit) Value
Α Rate of contribution to the environmental infectious pressure per infected individual (units per day) a1.00 × 100
β 1 Decay of environmental infectious pressure during spring (per day) 1.57 × 10−1
β 2 Decay of environmental infectious pressure during summer (per day) a1.44 × 10−1
β 3 Decay of environmental infectious pressure during autumn (per day) 1.50 × 10−1
β 4 Decay of environmental infectious pressure during winter (per day) 1.57 × 10−1
υ 1 Indirect transmission rate of the environmental infectious pressure in calves (per animal per day) 2.48 × 10−2
υ 2 Indirect transmission rate of the environmental infectious pressure in young stock (per animal per day) 2.48 × 10−2
υ 3 Indirect transmission rate of the environmental infectious pressure in adults (per animal per day) 1.37 × 10−2
γ The recovery rate of infection (per day) a1.00 × 10−1
D The rate of local spread among proximal holdings (per day per m) 0.11 × 10−5
  1. Parameters used to explore the spread of verotoxigenic Escherichia coli O157:H7 (VTEC O157) in the entire Swedish cattle population based on data reported to the Swedish Board of Agriculture during the period 01 July 2005 to 31 December 2013. The within-herd disease spread was modelled with a stochastic SISE compartment model with the two disease states: susceptible (S) and infected (I) and E representing the environmental compartment contaminated with VTEC O157 by infected animals. The decay of the environmental infectious pressure was varied in each of the four seasons: spring, summer, autumn, and winter. Individuals were divided into the following three age categories; calves 0–119 days, young stock 120–364 days and adults older than 364 days.
  2. aFixed value during model fit.