Gueldner Emily Katharina, Gilli Urs, Strube Christina, Schnyder Manuela
Institute of Parasitology, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 266a, 8057 Zurich, Switzerland.
IDEXX Diavet AG, Schlyffistrasse 10, 8806 Bäch, Switzerland.
Vet Parasitol. 2019 Feb;266:27-33. doi: 10.1016/j.vetpar.2018.12.013. Epub 2019 Jan 4.
The metastrongyloid nematode Aelurostrongylus abstrusus is a worldwide occurring feline lungworm. The spectrum of clinical signs in infected cats ranges from mild (e.g. nasal discharge or cough) to severe respiratory distress. The aim of this seroepidemiological study was to define prevalence and risk factors for A. abstrusus infections in Swiss cats, to assess the biogeographic distribution and to investigate the influence of temperature and altitude on the occurrence of this parasite. Sera of 4067 domestic cats were collected from all over Switzerland, tested for the presence of antibodies against A. abstrusus by a novel ELISA and the results correlated with biogeographic aspects. A subsample of 1000 datasets was used for risk factor analyses. Overall, 10.7% (434/4067, 95% confidence intervals [CI]: 9.7-11.7%) of the cats were tested positive, with variations from 0.0% to 20.0% among ten different biogeographic regions. Differences were significant between the Western (13.9%, CI: 11.4-16.7%) and the Eastern (9.2%, CI: 8.0-10.5%) Swiss Plateau, possibly attributable to the suitability of the areas for intermediate hosts. In total 90.3% (392/434) of the seropositive cats originated from regions lower than 700 m above sea level. Correspondingly, 98.9% (429/434) of positive samples were obtained from regions with a mean temperature higher than -2 °C in January, suggesting altitude and temperature being limiting factors for A. abstrusus infections in Switzerland. Concerning individual risk factors, prevalence was higher in intact (15.5%, CI: 9.5-23.4%) than in neutered cats (5.8%, CI: 7.9-10.4%). Young adult cats (aged 11-22 months) were significantly more often seropositive (10/76, 13.2%, CI: 6.5-22.9%) than kittens aged 1-10 months (1/34, 2.9%, CI: 0.1-15.3%) or adult and senior cats > 22 months (58/889, 6.5%, CI: 5-8.4%). Outdoor cats and cats presenting respiratory signs tend to be more often positive than indoor cats (p = 0.077) and animals without respiratory signs (p = 0.086), respectively. We here confirm that the use of a serological test can contribute to improve the identification of infected animals, through evaluation of risk factors on a population level and for a better management on an individual level, overcoming the challenges represented by faecal examinations and the correlated underestimation of the occurrence of A. abstrusus in cats.
后圆线虫类线虫隐匿猫圆线虫是一种在全球范围内存在的猫肺线虫。受感染猫的临床症状范围从轻微症状（如鼻分泌物或咳嗽）到严重的呼吸窘迫。这项血清流行病学研究的目的是确定瑞士猫中隐匿猫圆线虫感染的患病率和风险因素，评估生物地理分布，并调查温度和海拔对这种寄生虫出现的影响。从瑞士各地收集了4067只家猫的血清，通过一种新型酶联免疫吸附测定法（ELISA）检测针对隐匿猫圆线虫的抗体的存在情况，并将结果与生物地理因素相关联。1000个数据集的子样本用于风险因素分析。总体而言，10.7%（434/4067，95%置信区间[CI]：9.7 - 11.7%）的猫检测呈阳性，在十个不同的生物地理区域中，阳性率从0.0%到20.0%不等。瑞士高原西部（13.9%，CI：11.4 - 16.7%）和东部（9.2%，CI：8.0 - 10.5%）之间存在显著差异，这可能归因于这些地区对中间宿主的适宜性。总共90.3%（392/434）的血清阳性猫来自海拔低于700米的地区。相应地，98.9%（429/434）的阳性样本来自1月份平均温度高于 - 2°C的地区，这表明海拔和温度是瑞士隐匿猫圆线虫感染的限制因素。关于个体风险因素，未绝育猫的患病率（15.5%，CI：9.5 - 23.4%）高于绝育猫（5.8%，CI：7.9 - 10.4%）。年轻成年猫（11 - 22个月龄）血清阳性的频率（10/76，13.2%，CI：6.5 - 22.9%）显著高于1 - 10个月龄的小猫（1/34，2.9%，CI：0.1 - 15.3%）或大于22个月龄的成年猫和老年猫（58/889，6.5%，CI：5 - 8.4%）。户外猫和出现呼吸道症状的猫分别比室内猫（p = 0.077）和没有呼吸道症状的动物（p = 0.086）更常呈阳性。我们在此证实，通过在群体水平上评估风险因素以及在个体水平上进行更好的管理，使用血清学检测有助于提高对受感染动物的识别，克服粪便检查所带来的挑战以及隐匿猫圆线虫在猫中出现情况被相关低估的问题。
