Characteristics of Pigs Sampled.

Porcine cysticercosis (PC) is an important public health problem, especially in sub-Saharan Africa, but limited information is available on the prevalence of infection in pigs entering the food chain. Existing diagnostic methods vary in accuracy and efficiency; whole carcass dissection is the most reliable method but is labour-intensive and destroys the carcass so can only be used in a research setting. Serological tests offer lower specificity, while meat inspection and lingual examination lack sensitivity, hampering accurate estimates and the removal of infected pigs from the food chain. Here, we provide the first estimates of PC prevalence in abattoirs in Rwanda. We use whole carcass dissection to determine the diagnostic accuracy of a commercial antigen-ELISA to estimate the true prevalence of infection across Rwanda and identify Taenia species affecting local pigs. We carried out a cross-sectional survey in 6 abattoirs across Rwanda (n = 744 pigs), with whole carcass dissection of a subset of 67 pigs. Cysts were detected in 20/67 (30%) of carcasses, with >1000 cysts in 9/20 (45%) of infected pigs. All cysts were identified as Taenia solium by PCR-RFLP, with no cysts of Taenia hydatigena found. The antigen-ELISA showed a sensitivity of 90% (95% CI: 68–99) and specificity of 85% (95% CI: 72–94), when compared to dissection. Using these estimates, the true prevalence was calculated as 25–43% in two abattoirs in south-west Rwanda, and 2–3% in the rest of the country. Fewer than half of infected pigs were detected by tongue palpation and post-mortem veterinary inspection. Our data indicate a high prevalence of PC in Rwandan abattoirs. Tongue palpation and veterinary inspections, as currently carried out, have little impact in removing cyst-infested pigs from the food chain. Additional interventions are needed, such as proper pig husbandry, treatment and vaccination against cysticercosis, health education, improved sanitation and hygiene, and improved processing and cooking of meat.

猪囊尾蚴病（Porcine cysticercosis, PC）是一类重要的公共卫生问题，尤其在撒哈拉以南非洲地区，但目前关于进入食品链的生猪感染流行率的相关信息仍较为有限。现有诊断方法的准确性与效率参差不齐；全胴体剖检是最为可靠的诊断方法，但该方法耗力且会破坏胴体，仅可用于科研场景。血清学检测的特异性较低，而肉类检疫与舌部检查则敏感性不足，这阻碍了准确的流行率估算以及受感染生猪从食品链中的剔除工作。
本研究首次对卢旺达屠宰场中的猪囊尾蚴病流行率进行了估算。我们采用全胴体剖检来确定商用抗原ELISA（antigen-ELISA）的诊断准确性，以此估算卢旺达全国范围内的真实感染流行率，并鉴定感染当地生猪的带绦虫属（Taenia）物种。我们在卢旺达全国6家屠宰场开展了一项横断面调查，共纳入744头生猪，并对其中67头生猪的全胴体进行了剖检。在67头受检胴体中，20头（30%）检出囊尾蚴，其中9头（45%）感染猪的囊尾蚴数量超过1000个。经聚合酶链反应-限制性片段长度多态性（PCR-RFLP）鉴定，所有囊尾蚴均为猪带绦虫（Taenia solium），未检出泡状带绦虫（Taenia hydatigena）。以全胴体剖检为金标准，商用抗原ELISA的敏感性为90%（95%置信区间：68~99），特异性为85%（95%置信区间：72~94）。基于上述估算结果，卢旺达西南部两家屠宰场的真实感染流行率为25%~43%，全国其余地区的真实感染流行率为2%~3%。
通过舌部触诊与宰后兽医检疫检出的感染生猪不足半数。本研究数据表明，卢旺达屠宰场中的猪囊尾蚴病流行率较高。当前采用的舌部触诊与兽医检疫措施，在将感染囊尾蚴的生猪从食品链中剔除方面效果甚微。
因此需要采取更多干预措施，包括规范生猪养殖、囊尾蚴病治疗与疫苗接种、健康教育、改善环境卫生与个人卫生，以及优化肉类加工与烹饪方式。