Abstract：
Taenia saginata is a zoonotic tapeworm of humans with bovines as its intermediate host (bovine cysticercosis). Traditional meat inspection is the main measure to identify the larval stage in carcasses and prevent human infection, but has a notoriously low sensitivity, especially in low prevalence settings. The legislation in multiple African countries mandates an incision in both triceps brachii muscles to detect the parasite as part of the normal post-mortem inspection, but this has an economic cost and is not universally mandated in other countries. The primary aim of this study was to investigate the epidemiology of bovine cysticercosis at an export abattoir in South Africa and determine the validity and cost of the triceps incision. Risk factors were investigated, and the effect of additional heart incisions on the current inspection. Four incisions were made into the heart in addition to the normal post-mortem inspection in 3353 carcasses. The proportion of positive animals with and without the cardiac and triceps incisions were compared using McNemar\'s chi-square tests, while risk factors were assessed using binary logistic regression. The economic impact of the triceps incision was estimated using a stochastic economic cost model. Thirty-three positive carcasses were identified for an apparent prevalence of 0.98 % (95 %CI, 0.69-1.36 %), while the true prevalence was estimated at 6.6 % (95 %CI, 4.3-8.8 %). All cysts were confirmed as T. saginata on histopathology with 70 % (95 %CI, 53-83 %) located in the heart. The additional cardiac incisions resulted in the detection of significantly more cases compared to the normal inspection method prevalence of 0.72 % (95 %CI, 0.47-1.05 %; P < 0.001). The apparent prevalence of T. saginata when omitting the triceps incision was not significantly lower compared to the prevalence when included in the inspection (P = 0.480). External feedlots (OR= 4.17, 95 %CI: 2.04-8.54, P < 0.001) and older animals (OR=3.90, 95 %CI: 1.17-13.03, P = 0.027) were associated with a positive detection. The current median annual financial cost to the food business operator from the triceps incision was estimated at $30387 (95 %CI: $0-$130696), with the proportion of deboned meat exported identified as the most important factor affecting cost (Spearman\'s rho=0.853). The identification of risk factors could aid in the development of a more effective risk-based inspection system. The current inspection should be modified to increase exposure of the heart and remove the triceps incisions. The latter should especially be considered given the minimal contribution to cysticercosis detection, the unsupported requirement for its inclusion specifically in Africa, and its economic impact, especially as beef exports increase.
摘要：
牛带虫是人类的人畜共患tape虫，以牛为中间宿主（牛囊虫病）。传统的肉类检验是识别尸体幼体阶段和防止人类感染的主要措施，但灵敏度非常低，尤其是在低患病率环境中。多个非洲国家的立法要求在肱三头肌的两个肌肉上进行切口，以检测寄生虫，作为正常验尸的一部分，但这有经济成本，在其他国家并没有普遍授权。这项研究的主要目的是调查南非出口屠宰场牛囊虫病的流行病学，并确定三头肌切口的有效性和成本。调查了危险因素，以及额外的心脏切口对当前检查的影响。除了对3353具尸体进行正常的验尸检查外，还在心脏中切开了四个切口。使用McNemar卡方检验比较有和没有肱三头肌切口的阳性动物的比例，而危险因素使用二元逻辑回归进行评估。使用随机经济成本模型估计了肱三头肌切口的经济影响。鉴定出33例阳性尸体的明显患病率为0.98％（95CI，0.69-1.36％），而实际患病率估计为6.6%(95CI,4.3-8.8%).所有囊肿在组织病理学上被证实为T.saginata,其中70%(95CI,53-83%)位于心脏。与正常检查方法的患病率0.72％相比，额外的心脏切口导致检测到更多的病例（95CI，0.47-1.05％；P<0.001）。与包括在检查中的患病率相比，省略肱三头肌切口时的saginata的明显患病率并没有显着降低（P=0.480）。外部饲养场（OR=4.17，95CI：2.04-8.54，P<0.001）和老年动物（OR=3.90，95CI：1.17-13.03，P=0.027）与阳性检测相关。目前，由于肱三头肌切口对食品企业经营者造成的年度财务成本中位数估计为30387美元（95CI：0-130696美元），脱骨肉的出口比例被确定为影响成本的最重要因素(Spearman’srho=0.853)。识别风险因素可以帮助开发更有效的基于风险的检查系统。应修改当前检查以增加心脏的暴露并移除三头肌切口。考虑到对囊虫病检测的贡献最小，应特别考虑后者，特别是在非洲，不支持将其纳入的要求，以及它的经济影响，特别是随着牛肉出口的增加。
