Veterinary foot-and-mouth disease outbreak data

Data of the spatial locations and time of farms infected by veterinary foot-and-mouth disease in the county of Cumbria, UK, over a course of nearly 250 days between February and August in 2001. There are 410 infected farms (the cases), and 1866 uninfected farms (the controls). The data have been jittered and randomly thinned by an unspecified amount to preserve anonymity.

Format

fmd is a named list with two members:

$cases

An object of class ppp giving the spatial locations of the 410 infected farms within a polygonal study region representing the county of Cumbria. The marks component of this object contain the integer day of infection (from beginning of study period).

$controls

An object of class ppp defined over the same spatial study region with the locations of the 1866 uninfected farms.

Acknowledgements

The Animal and Plant Health Agency (APHA), UK, provided permission to use this dataset.

References

Fernando, W.T.P.S. and Hazelton, M.L. (2014), Generalizing the spatial relative risk function, Spatial and Spatio-temporal Epidemiology, 8, 1-10.

Keeling M, Woolhouse M, Shaw D, Matthews L, Chase-Topping M, Haydon D, et al. (2001), Dynamics of the 2001 UK foot and mouth epidemic: stochastic dispersal in a heterogeneous landscape, Science, 294, 813-817.

Lawson A, Zhou H. (2005), Spatial statistical modeling of disease outbreaks with particular reference to the UK foot and mouth disease (FMD) epidemic of 2001, Preventative Veterinary Medicine, 71, 141-156.

Examples

data(fmd)
summary(fmd$cases)
#> Marked planar point pattern:  410 points
#> Average intensity 0.08894847 points per square unit
#> 
#> Coordinates are given to 5 decimal places
#> 
#> marks are numeric, of type ‘integer’
#> Summary:
#>    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
#>   20.00   45.25   61.50   90.78  137.75  220.00 
#> 
#> Window: polygonal boundary
#> single connected closed polygon with 477 vertices
#> enclosing rectangle: [324.538, 404.786] x [482.4227, 560.6303] units
#>                      (80.25 x 78.21 units)
#> Window area = 4609.41 square units
#> Fraction of frame area: 0.734
summary(fmd$controls)
#> Planar point pattern:  1866 points
#> Average intensity 0.404824 points per square unit
#> 
#> Coordinates are given to 5 decimal places
#> 
#> Window: polygonal boundary
#> single connected closed polygon with 477 vertices
#> enclosing rectangle: [324.538, 404.786] x [482.4227, 560.6303] units
#>                      (80.25 x 78.21 units)
#> Window area = 4609.41 square units
#> Fraction of frame area: 0.734
 
par(mfrow=c(1,2))
plot(fmd$cases)
plot(fmd$controls)