Basso Walter, Grandt Lisa-Maria, Magnenat Anne-Laure, Gottstein Bruno, Campos Miguel
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
Small Animal Clinic, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
Parasitol Res. 2019 Jan;118(1):255-266. doi: 10.1007/s00436-018-6173-3. Epub 2018 Dec 14.
Strongyloides stercoralis is a worldwide-distributed intestinal nematode affecting mainly humans and dogs. Canine strongyloidosis is generally characterised by diarrhoea, malabsorption and bronchopneumonia, and may be fatal in cases of impaired immunity. In recent years, molecular and epidemiological studies suggested that host-adapted populations of S. stercoralis with different zoonotic potential may exist. Clinical and subclinical cases of S. stercoralis infection have been increasingly diagnosed in imported (France, Belgium, Bulgaria) and locally born dogs in Switzerland, showing that this parasite is currently circulating in Europe. Three of these clinical cases will be described here. All three dogs presented severe disease, characterised by harsh diarrhoea, dehydration, vomiting, respiratory and/or neurologic signs, and needed intensive care and hospitalisation. One of these dogs was related to a Swiss breeding kennel, in which the infection was subsequently diagnosed in several other dogs. Faeces were analysed by three coproscopical methods including (i) the Baermann technique, which consistently identified the typical S. stercoralis first-stage larvae in both clinical and subclinical infections, (ii) the sedimentation-zinc chloride flotation and (iii) sodium acetate-acetic acid-formalin concentration (SAFC) methods, which allowed the additional identification of parasitic females and/or eggs in two of the clinical cases. Interestingly, S. stercoralis isolated from all three independent clinical cases exhibited an identical genetic background on the nuclear 18S rDNA (fragment involving hypervariable regions I and IV) and the mitochondrial cytochrome oxidase subunit I (cox1) loci, similar to that of zoonotic isolates from other geographical regions, and not to that of dog-adapted variants. Due to the clinical relevance and zoonotic potential of this parasite, the awareness of both diagnosticians and clinicians is strongly required.
粪类圆线虫是一种广泛分布于全球的肠道线虫，主要感染人类和犬类。犬类粪类圆线虫病通常表现为腹泻、吸收不良和支气管肺炎，在免疫力受损的情况下可能致命。近年来，分子和流行病学研究表明，可能存在具有不同人畜共患病潜力的宿主适应性粪类圆线虫种群。在瑞士，从国外进口的（法国、比利时、保加利亚）以及本地出生的犬类中，粪类圆线虫感染的临床和亚临床病例诊断越来越多，表明这种寄生虫目前正在欧洲传播。这里将描述其中三例临床病例。所有三只犬均表现出严重疾病，特征为剧烈腹泻、脱水、呕吐、呼吸和/或神经症状，需要重症监护和住院治疗。其中一只犬与瑞士的一个繁殖犬舍有关，随后在该犬舍的其他几只犬中也诊断出了感染。通过三种粪便检查方法对粪便进行了分析，包括：（i）贝尔曼氏法，该方法在临床和亚临床感染中均能持续鉴定出典型的粪类圆线虫第一期幼虫；（ii）沉淀 - 氯化锌漂浮法；（iii）醋酸钠 - 醋酸 - 甲醛浓缩法（SAFC法），后两种方法在两例临床病例中还额外鉴定出了寄生雌虫和/或虫卵。有趣的是，从所有三例独立临床病例中分离出的粪类圆线虫在核18S rDNA（涉及高变区I和IV的片段）和线粒体细胞色素氧化酶亚基I（cox1）基因座上表现出相同的遗传背景，类似于来自其他地理区域的人畜共患分离株，而不同于适应犬类的变体。由于这种寄生虫的临床相关性和人畜共患病潜力，强烈需要提高诊断医生和临床医生的认识。
