Classical Swine Fever (CSF) is a porcine viral disease that has severe consequences on animal health, welfare, and production. In Switzerland six broad levels of on-farm intervention measures are considered depending on the assessment of the epidemiological status of the focal farm, of the neighbouring farms and of the country; Basic biosecurity (I0), Basic biosecurity with reinforced surveillance (I0b), Surveillance zone (I1), Protection Zone (I2), Quarantine (I3) and Culling (I4). In 2014 an exclusion component was added to allow testing for CSF without implementing quarantine or movement restrictions. The objective of this study was to assess the cost-effectiveness of this current system.

A stochastic farm-based model was developed which simulates the spread of CSF through Swiss pig farms in space and time, taking account of the implementation of intervention measures based on the system of surveillance. Two measures of effectiveness of the current system were assessed 1) the number of infected farms per outbreak and 2) the probability of implementing an intervention strategy (I0-I4) that is not strong enough given the true epidemiological status. Costs of the outbreak included the cost of implementing interventions and the costs of culling all animals determined to be infected over the course of the outbreak

The median number of infected farms per outbreak was 80. Among all the simulations, 1.4% (14/1000 simulations) did not lead to an outbreak. The median probabilities of errors, over all simulations, for the different possible intervention measures to be implemented at the time when a farm becomes infectious were highest for basic biosecurity level with reinforced surveillance (I0b), then surveillance zone measures (I1), basic biosecurity level (I0), and finally protection zone measures (I2) with the lowest probability. The median costs endorsed at federal level were 3.4 million CHF per outbreak.

The cost-effectiveness of the system was evaluated as medium. The exclusion component was evaluated as good, balancing its low price of implementation, the level of biosecurity implemented at farms and the risk of CSF incursion in Switzerland. We suggest that changes in the surveillance strategy that would increase the probability of reinforced surveillance (I0b, I1, I2) to be implemented at the time a farm becomes infectious would increase the cost-effectiveness of the system. Such changes could include increasing awareness among stakeholders or developing new actions after the first outbreak, such as more intense investigations among connected farms.

古典猪瘟（CSF）是一种猪病毒性疾病，会对动物的健康，福利和生产产生严重影响。在瑞士，根据对重点农场，邻近农场和国家的流行病学状况的评估，考虑了六种广泛的农场干预措施：基本生物安全（I0），加强监视的基本生物安全（I0b），监视区（I1），保护区（I2），隔离区（I3）和剔除（I4））。2014年，添加了一个排除组件，以允许对CSF进行测试而无需实施隔离或移动限制。这项研究的目的是评估当前系统的成本效益。

建立了基于随机农场的模型，该模型模拟了脑脊液在瑞士猪场中的时空分布，并考虑了基于监控系统的干预措施的实施。评估了当前系统有效性的两个衡量指标：1）每次暴发的受感染农场数量和2）鉴于实际的流行病学状况，实施干预策略（I0-I4）的可能性不够强。爆发的成本包括实施干预措施的成本以及扑灭所有在爆发过程中被确定感染动物的成本

每次爆发的受感染农场的中位数为80个。在所有模拟中，有1.4％（14/1000个模拟）未导致爆发。在所有模拟中，对于农场发生传染时要实施的各种可能的干预措施，发生错误的中位概率在加强监控（I0b）的基础生物安全水平下最高，其次是监视区措施（I1），基本生物安全等级（I0），最后以最小的概率进行保护区措施（I2）。联邦政府认可的每次爆发中位数成本为340万瑞士法郎。

该系统的成本效益被评估为中等。排除因素的评价为良好，平衡了其实施成本低，农场实施的生物安全水平以及瑞士脑脊液入侵的风险。我们建议，改变监视策略会增加在农场受到感染时实施加强监视的可能性（I0b，I1，I2），这会增加系统的成本效益。此类变化可能包括提高利益相关者的意识或在首次爆发后制定新的行动，例如对相连农场进行更深入的调查。