Table 1.
Sensitivity analysis on the parametric shape of the function representing the time-dependent transmission rate: estimates and 95% confidence intervals (CIs) of the parameters of the infectious potential function distribution, estimated basic reproduction ratio R0, mean generation time Tg and goodness of fit tests on observed and external (Andraud et al. 2008) data according to the assumed duration of the latent period. (β(τ), parametric function of infectious potential; k, θ, parameters of β(τ); R0, basic reproduction ratio defined as the average number of secondary infections occurring from a single infected animal during its infectious period in a totally susceptible population; Tg, mean generation time defined as the sum of the mean latent period and the mean infectious period; R2, coefficient of determination; ND, not defined.)
| parameters (CI) | goodness of fit on observed data | goodness of fit on external data | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| function shape | latent period (days) | k | θ | R0 | mean generation time Tg (CI) | Χ2 | p-value | R2 | Χ2 | p-value | R2 |
| gamma | 6 | 3.6 (0.7,6.6) | 3.4 (1.1,5.7) | 5.3 (3.3,7.2) | 18.3 (6.7,25.4) | 0.31 | 0.98 | 0.96 | 7.67 | 0.36 | 0.23 |
| 7 | 3.2 (1.2,5.3) | 3.5 (1.2,5.9) | 5.2 (3.2,7.2) | 18.4 (8.3,27.4) | 0.3 | 0.98 | 0.97 | 4.76 | 0.69 | 0.5 | |
| 8 | 2.9 (1.5,4.2) | 3.7 (1.3,6.1) | 5.2 (3.1,7.4) | 18.6 (9.9,27.5) | 0.3 | 0.99 | 0.97 | 2.56 | 0.86 | 0.9 | |
| 9 | 2.5 (1.6,3.3) | 3.9 (1.4,6.4) | 5.2 (2.9,7.6) | 18.7 (11.3,26.5) | 0.29 | 0.99 | 0.97 | 2.91 | 0.82 | 0.86 | |
| 10 | 2.1 (1.7,2.6) | 4.1 (1.6,6.7) | 5.3 (2.5,8.1) | 18.7 (12.7,24.9) | 0.28 | 0.99 | 0.97 | 7.44 | 0.28 | 0.53 | |
| Weibull | 6 | 12.9 (8.5,17.4) | 1.7 (1.5,1.9) | 5.4 (3.3,7.5) | 17.5 (13.6,21.2) | 0.31 | 0.99 | 0.96 | 10.76 | 0.15 | 0.11 |
| 7 | 12.2 (8.6,15.9) | 1.6 (1.5,1.8) | 5.2 (3.3,7.1) | 17.9 (14.7,20.9) | 0.31 | 0.98 | 0.95 | 7.55 | 0.37 | 0.23 | |
| 8 | 11.5 (8.5,14.4) | 1.6 (1.4,1.7) | 5.0 (3.3,6.8) | 18.3 (15.7,20.7) | 0.31 | 0.98 | 0.96 | 4.41 | 0.62 | 0.55 | |
| 9 | 10.7 (8.3,13.1) | 1.5 (1.4,1.6) | 4.9 (3.3,6.6) | 18.6 (16.6,20.6) | 0.3 | 0.99 | 0.96 | 2.84 | 0.83 | 0.93 | |
| 10 | 9.8 (7.9,11.8) | 1.4 (1.4,1.5) | 4.9 (3.2,6.5) | 18.9 (17.2,20.5) | 0.3 | 0.99 | 0.96 | 7.08 | 0.31 | 0.56 | |
| lognormal | 6 | 2.42 (2.41,2.43) | 0.47 (0.46,0.48) | 5.6 (2.7,8.6) | 18.4 (18.3,18.6) | 0.23 | 0.99 | 0.98 | 5.89 | 0.55 | 0.33 |
| 7 | 2.32 (2.31,2.32) | 0.50 (0.49,0.51) | 5.7 (2.3,9.2) | 18.4 (18.3,18.6) | 0.22 | 0.99 | 0.98 | 2.73 | 0.91 | 0.77 | |
| 8 | 2.20 (2.19,2.21) | 0.54 (0.53,0.56) | 5.9 (1.8,10.1) | 18.4 (18.2,18.5) | 0.2 | 0.99 | 0.98 | 1.15 | 0.98 | 0.99 | |
| 9 | 2.06 (2.05,2.07) | 0.60 (0.58,0.61) | 6.3 (0.7,11.9) | 18.2 (18,18.4) | 0.17 | 0.99 | 0.98 | 3.6 | 0.73 | 0.8 | |
| 10 | 1.86 (1.85,1.88) | 0.67 (0.66,0.69) | 7.0 (ND,16.08) | 17.9 (17.7,18) | 0.15 | 0.99 | 0.98 | 8.95 | 0.17 | 0.5 | |