In the US the simulated curves for the distance-only constant infectivity model are shown in figure 5e and for the England and Wales parameters in figure 5f. In both cases, the mean simulated and observed curve are very comparable, with the distance-only constant infectivity model giving peak incidence in the same week as observed. Figure 5g shows the observed week of infection against the simulated week of infection for all 1000 simulated epidemics. There is good correlation between the observed and simulated weeks of infection for both parametrizations.