A model of bovine tuberculosis in the badger Meles meles:: an evaluation of control strategies

1. An individual-based stochastic simulation model was used to investigate the control of bovine tuberculosis (TB) in the European badger Meles meles. Nearly all population and epidemiological parameters were derived from one study site, and the transmission of TB from badgers to cattle was included. The latter is an essential step if reactive badger control strategies are to be modelled. 2. The model appeared to underestimate slightly the rate of population recovery following widespread culling. This may have been due to simulating an isolated population with no immigration and no compensatory increase in fecundity. This should not affect the relative efficacy of each control strategy, but does require further investigation. 3. Of the historical methods of badger control, gassing and the 'clean ring' strategies were the most effective at reducing disease prevalence in the badger and cattle herd breakdown rates. These results agree with those of earlier models. 4. The proactive badger removal operation as part of the current field trial should cause a dramatic decrease in the number of cattle herd breakdowns, but also has the greatest effect on the badger population size. 5. The proactive use of a live test to detect TB, followed by vaccination, appears to reduce substantially cattle herd breakdowns and disease prevalence in the badger. 6. Three combined control strategies gave the best initial reduction in cattle herd breakdown rate and disease prevalence in the badger: (i) a proactive cull followed by reactive test and cull; (ii) a continued vaccination and proactive test and cull; and (iii) a continuous proactive test and cull. 7. The results of simulation models suggest that badger vaccination is a very good method of TB control. This is at odds with simple models and requires further investigation.