Hansen Rikke Koch, Nielsen Lisbeth Harm, El Tholth Mahmoud, Haesler Barbara, Foddai Alessandro, Alban Lis
Department for Food Safety and Veterinary Issues, Danish Agriculture & Food Council, Copenhagen, Denmark.
Department of Economics, School of Arts and Social Sciences, City University of London, London, United Kingdom.
Front Vet Sci. 2018 Jun 5;5:92. doi: 10.3389/fvets.2018.00092. eCollection 2018.
Denmark has not had cases of bovine tuberculosis (bovTB) for more than 30 years but is obliged by trade agreements to undertake traditional meat inspection (TMI) of finisher pigs from non-controlled housing to detect bovTB. TMI is associated with higher probability of detecting bovTB but is also more costly than visual-only inspection (VOI). To identify whether VOI should replace TMI of finisher pigs from non-controlled housing, the cost of error - defined here as probability of overlooking infection and associated economic costs - should be assessed and compared with surveillance costs. First, a scenario tree model was set up to assess the ability of detecting bovTB in an infected herd () calculated for three within-herd prevalences, (1, 5 and 10%), for four different surveillance scenarios (TMI and VOI with or without serological test, respectively). was calculated for six consecutive 4-week surveillance periods until predicted bovTB detection (considered high-risk periods ). 1- was probability of missing all positives by each . Next, probability of spread of infection, and number of infected animals moved were calculated for each . Costs caused by overlooking bovTB were calculated taking into account , 1-, eradication costs, and trade impact. Finally, the average annual costs were calculated by adding surveillance costs and assuming one incursion of bovTB in either 1, 10 or 30 years. Input parameters were based on slaughterhouse statistics, literature and expert opinion. Herd sensitivity increased by high-risk period and within-herd prevalence. Assuming =5%, reached median 90% by 2nd for TMI, whereas for VOI this would happen after 6th . Serology had limited impact on . The higher the probability of infection, the higher the probability of detection and spread. TMI resulted in lowest average annual costs, if one incursion of bovTB was expected every year. However, when assuming one introduction in 10 or 30 years, VOI resulted in lowest average costs. It may be more cost-effective to focus on imported high-risk animals coming into contact with Danish livestock, instead of using TMI as surveillance on all pigs from non-controlled housing.
丹麦已有30多年未出现牛结核病（bovTB）病例，但根据贸易协定，有义务对来自非受控养殖环境的育肥猪进行传统肉类检验（TMI），以检测牛结核病。传统肉类检验发现牛结核病的概率更高，但成本也高于仅进行目视检查（VOI）。为了确定目视检查是否应取代对来自非受控养殖环境的育肥猪的传统肉类检验，应评估错误成本（在此定义为忽略感染的概率及相关经济成本），并与监测成本进行比较。首先，建立了一个情景树模型，以评估在三种不同的畜群患病率（1%、5%和10%）下，针对四种不同监测情景（分别为有或无血清学检测的传统肉类检验和目视检查）计算出的在感染畜群中检测到牛结核病的能力。针对连续六个为期四周的监测期计算该能力，直至预测到牛结核病检测结果（视为高风险期）。1减去该能力即为每种监测方法遗漏所有阳性病例的概率。接下来，针对每种监测方法计算感染传播的概率、以及感染动物移动的数量。考虑到遗漏牛结核病造成的成本、遗漏概率、根除成本和贸易影响，计算出遗漏牛结核病所导致的成本。最后，通过加上监测成本并假设在1年、10年或30年中发生一次牛结核病入侵事件，计算出平均年度成本。输入参数基于屠宰场统计数据、文献和专家意见。畜群敏感性随高风险期和畜群患病率的增加而提高。假设患病率为5%，传统肉类检验在第二个四周监测期时，该能力的中位数达到90%，而目视检查则要在第六个四周监测期时才会达到。血清学检测对该能力的影响有限。感染概率越高，检测和传播的概率就越高。如果预计每年发生一次牛结核病入侵事件，传统肉类检验导致的平均年度成本最低。然而，当假设在10年或30年中发生一次引入事件时，目视检查导致的平均成本最低。专注于对与丹麦牲畜接触的进口高风险动物进行检测，而不是对来自非受控养殖环境的所有猪使用传统肉类检验进行监测，可能更具成本效益。
