Model of btb: cattle and live test
Journal of Applied Ecology,
Volume 38,Number 3, June 2001, pp. 520-535(16)
An individual-based stochastic simulation model was used to
investigate the control of btb in the badger by using a live test to determine the presence of
infection. The model was an extension of earlier models, and nearly
all population and epidemiological parameters were derived from one
This is the first TB model to examine sex differences in
disease epidemiology, and the transmission of TB from badgers to
cattle. The latter is an essential step if reactive badger control
strategies are to be modelled.
Heterogeneity was introduced to the simulation model by the
use of a carrying capacity, which defined the maximum number of
breeding females per social group.
The prevalence of TB, and the number of simulated cattle herd
breakdowns, was reduced for all control strategies using a live
test, namely localised culling, ring culling and proactive culling.
However, only proactive culling resulted in a marked reduction in
these values within a few years.
If trapping efficacy was increased above its current value
(80%), this did not improve the effectiveness of these culling
If the number of individual badgers caught and tested
per social group was doubled from two to four animals per group,
then the overall level of effectiveness of these strategies could be
The effectiveness could be improved if the sensitivity of the
live test was increased, but did not continue to show an improvement
above a sensitivity of about 70%.
Given the constraints of the current live test sensitivity
(41%) and a trapping efficacy of 80%, proactive culling, following
the testing of four individuals per group, led to an average of
three cattle herd breakdowns per year in the simulation, compared
with an average of 31 per year when simulating the live test trial
as used between 1994 and 1996.
control; individual-based model; TB; wildlife