Comparison of serological and milk tests for bovine brucellosis using a Monte Carlo simulation model

European Union (EU) Directive 97/12/EC allows the trade of cattle within the EU of animals originating from an 'officially brucellosis-free herd'. To qualify for this status, a number of different programmes must be implemented. Each EU Member Country is free to decide which procedure to use to qualify herds. The authors conducted a study to compare the merits and costs of testing programmes given in the Directive and of some alternative testing strategies. The effectiveness of testing programmes was evaluated by a Monte Carlo simulation model. Programmes listed in the Directive do not appear to have identical sensitivity and specificity. Simulations of the programmes showed that milk testing may be more effective and efficient than blood testing to identify infected herds. Results indicated that it could be advisable that legislation, rather than defining very detailed procedures both for laboratory tests and testing programmes, should establish minimal requirements in terms of efficacy of testing procedures (i.e. the probability of detecting an infected herd).