What can we expect?

What can we expect?

[Image from: Cliff, A. D. and P. Haggett. 1988. Atlas of Disease Distributions: Analytic Approaches to Epidemiological Data. Blackwell, Ltd., Oxford, UK.]

Cliff and Ord suggest that the appropriate Kendall type for rabies is Type 1 (as given in the plot above), because the recovery rate from rabies is 0. In a moment we'll see what actually results....

The plot above shows the expected response of raccoon populations to the introduction of rabies (although it was prepared with foxes in mind!): there is a sharp drop in population, due to the high mortality, followed by oscillatory variation in populations. This oscillation is due to the sustainability of rabies in small populations (below a certain critical population level, rabies can't be sustained); when the population rises above the critical level without rabies pressure, however, rabies can reinvade, resulting again in a reduction to subcritical population levels, and so on, and on, and on....