Animal Parasitic Diseases Laboratory, United States Department of Agriculture, Agricultural Research Service, Animal and Natural Resources Institute, Beltsville, MD 20705-2350, USA.
Zoonoses Public Health. 2010 Dec;57(7-8):e116-23. doi: 10.1111/j.1863-2378.2009.01296.x.
Pigs infected with the zoonotic parasite Trichinella spiralis were detected on a farm in Maryland during an animal welfare investigation. Sera and/or tissues were collected from 49 pigs and three pig carcasses (7 weeks of age to adult, mixed sex). The tissues were tested for the presence of T. spiralis muscle larvae (ML) by tissue digestion, and the sera were tested for the presence of anti-Trichinella antibodies by ELISA. Seventeen of 50 (34%) pigs were infected with T. spiralis based on tissue digestion. Of these 17 pigs, sera were collected from 16; nine were serologically positive, three sera had OD values that were very close to the positive cut-off (0.30), but were still negative, and four were negative (suggesting that they had become infected within a few weeks of testing). All pigs that tested negative by tissue digestion for ML were also ELISA negative. The farm was subsequently depopulated of pigs. Six months later, testing of trapped scavenging mammals in the farm environment demonstrated that 41% were infected with T. spiralis. After 12 months, 10% of trapped animals were T. spiralis positive, and after 18 months, T. spiralis could not be detected in the scavenging mammal population surrounding the farm. Results of the study suggest that T. spiralis, typically transmitted in the peridomestic rat-pig-human cycle in the US, was not maintained in scavenging mammals in the absence of infected pigs.
在马里兰州的一次动物福利调查中，在一个农场发现了感染人畜共患寄生虫旋毛虫的猪。从 49 头猪和 3 头猪尸（7 周龄至成年，混合性别）中采集了血清和/或组织。通过组织消化检测组织中是否存在旋毛虫肌肉幼虫（ML），通过 ELISA 检测血清中是否存在抗旋毛虫抗体。根据组织消化，50 头猪中有 17 头（34%）感染了旋毛虫。在这 17 头猪中，从 16 头采集了血清；9 份血清呈阳性，3 份血清的 OD 值非常接近阳性截止值（0.30），但仍为阴性，4 份为阴性（表明它们在检测后的几周内感染了）。所有经 ML 组织消化检测呈阴性的猪也均 ELISA 阴性。农场随后清空了猪群。六个月后，对农场环境中捕获的食腐哺乳动物进行检测，结果显示 41%感染了旋毛虫。12 个月后，10%的被捕食动物呈旋毛虫阳性，18 个月后，农场周围的食腐哺乳动物中无法检测到旋毛虫。研究结果表明，在美国，旋毛虫通常通过家庭周围的鼠-猪-人循环传播，在没有感染猪的情况下，无法在食腐哺乳动物中维持。
