University of Surrey, School of Veterinary Medicine, Daphne Jackson Road, University of Surrey, Guildford, Surrey GU2 7AL, UK.
Queen's University, Institute for Global Food Security, Biological Sciences Building, 19 Chlorine Gardens, BT9 5DL Belfast, UK.
Int J Parasitol. 2024 May;54(6):303-310. doi: 10.1016/j.ijpara.2024.02.003. Epub 2024 Mar 6.
Toxocara canis and Toxocara cati are globally distributed, zoonotic roundworm parasites. Human infection can have serious clinical consequences including blindness and brain disorders. In addition to ingesting environmental eggs, humans can become infected by eating infective larvae in raw or undercooked meat products. To date, no studies have assessed the prevalence of Toxocara spp. larvae in meat from animals consumed as food in the UK or assessed tissue exudates for the presence of anti-Toxocara antibodies. This study aimed to assess the potential risk to consumers eating meat products from animals infected with Toxocara spp. Tissue samples were obtained from 155 different food producing animals in the south, southwest and east of England, UK. Tissue samples (n = 226), either muscle or liver, were processed by artificial digestion followed by microscopic sediment evaluation for Toxocara spp. larvae, and tissue exudate samples (n = 141) were tested for the presence of anti-Toxocara antibodies using a commercial ELISA kit. A logistic regression model was used to compare anti-Toxocara antibody prevalence by host species, tissue type and source. While no larvae were found by microscopic examination after tissue digestion, the overall prevalence of anti-Toxocara antibodies in tissue exudates was 27.7%. By species, 35.3% of cattle (n = 34), 15.0% of sheep (n = 60), 54.6% of goats (n = 11) and 61.1% of pigs (n = 18) had anti-Toxocara antibodies. Logistic regression analysis found pigs were more likely to be positive for anti-Toxocara antibodies (odds ration (OR) = 2.89, P = 0.0786) compared with the other species sampled but only at a 10% significance level. The high prevalence of anti-Toxocara antibodies in tissue exudates suggests that exposure of food animals to this parasite is common in England. Tissue exudate serology on meat products within the human food chain could be applied in support of food safety and to identify practices that increase risks of foodborne transmission of zoonotic toxocariasis.
犬弓首蛔虫和猫弓首蛔虫是分布广泛的、人畜共患的圆形线虫寄生虫。人类感染可能会导致严重的临床后果，包括失明和脑部疾病。除了摄入环境中的虫卵，人类还可能通过食用生的或未煮熟的肉产品中的感染性幼虫而感染。迄今为止，尚无研究评估在英国作为食物消费的动物的肉类中是否存在弓首属幼虫，也没有评估组织渗出液中是否存在抗弓首属抗体。本研究旨在评估食用来自感染弓首属寄生虫的动物的肉产品的消费者面临的潜在风险。从英国南部、西南部和东部的 155 种不同的食品生产动物中获得组织样本。肌肉或肝脏的组织样本（n=226）通过人工消化处理，然后对弓首属幼虫进行显微镜沉淀物评估，141 份组织渗出液样本（n=141）使用商业 ELISA 试剂盒检测抗弓首属抗体的存在。使用逻辑回归模型比较宿主物种、组织类型和来源的抗弓首属抗体的流行率。尽管在组织消化后显微镜检查未发现幼虫，但组织渗出液中抗弓首属抗体的总流行率为 27.7%。按物种分类，35.3%的牛（n=34）、15.0%的羊（n=60）、54.6%的山羊（n=11）和 61.1%的猪（n=18）具有抗弓首属抗体。逻辑回归分析发现，与其他取样物种相比，猪更有可能对弓首属抗体呈阳性（优势比（OR）=2.89，P=0.0786），但仅在 10%的显著水平。组织渗出液中的抗弓首属抗体高流行率表明，英格兰的食用动物暴露于这种寄生虫很常见。在人类食物链中的肉类产品中进行组织渗出液血清学检测可以用于支持食品安全，并确定增加食源性传播动物弓首线虫病风险的做法。
