Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
College of Forest Resources and Environmental Science, Michigan Tech University, Houghton, Michigan 49931, USA.
J Wildl Dis. 2023 Jul 1;59(3):432-441. doi: 10.7589/JWD-D-22-00152.
Cytauxzoonosis is a fatal tick-borne disease in domestic cats caused by infection with the apicomplexan Cytauxzoon felis. Bobcats are the natural wild-vertebrate reservoirs for C. felis, and infections are typically subclinical and chronic in this species. The present study was done to determine the prevalence and geographic distribution of C. felis infection in wild bobcats from Oklahoma and the occurrence in northwestern Texas. Tongue samples from 360 bobcats were collected from 53 counties in Oklahoma and 13 samples from three counties in Texas. For DNA extracted from each tongue sample, a probe-based droplet digital PCR assay was performed targeting the C. felis mitochondrial gene cytochrome c oxidase subunit III (cox3). Prevalence of C. felis infection was calculated for each county sampled, and data from individual counties were combined according to geographic regions and compared using chi-square tests. Overall prevalence of C. felis in bobcats from Oklahoma was 80.0% (95% confidence interval [CI], 75.6-83.8). The prevalence of infection was >90% for bobcats from central, northeastern, south-central, and southeastern regions of Oklahoma, but <68% for bobcats from northwestern and southwestern regions. Bobcats from central counties in Oklahoma were 25.693 times more likely to be infected with C. felis compared to all other bobcats sampled from the state. Higher prevalence estimates of C. felis in bobcats appeared to be in counties where known tick vectors are most common. Occurrence of C. felis in bobcats from northwestern Texas was 30.8% (95% CI, 12.4%-58.0%) based on 13 samples. Results of this study support the utilization of bobcats as sentinel animals to identify geographic areas with risk of C. felis infection to domestic cats.
细胞球虫病是一种由细胞球虫属感染引起的致命蜱传疾病，可感染家猫。山猫是细胞球虫属的天然野生脊椎动物宿主，在该物种中感染通常为亚临床和慢性的。本研究旨在确定俄克拉荷马州野生山猫中细胞球虫属感染的流行率和地理分布，并确定德克萨斯州西北部的感染情况。从俄克拉荷马州的 53 个县采集了 360 只山猫的舌样本，从德克萨斯州的 3 个县采集了 13 个样本。对于从每个舌样本中提取的 DNA，使用针对细胞球虫属线粒体基因细胞色素 c 氧化酶亚基 III (cox3) 的基于探针的液滴数字 PCR 检测方法进行检测。计算了每个采样县的细胞球虫属感染率，并根据地理区域合并各县的数据，并使用卡方检验进行比较。从俄克拉荷马州采集的山猫中细胞球虫属感染的总体流行率为 80.0%（95%置信区间[CI]，75.6-83.8）。来自俄克拉荷马州中部、东北部、中南部和东南部地区的山猫感染率>90%，但来自西北部和西南部地区的山猫感染率<68%。与从该州采集的所有其他山猫相比，来自俄克拉荷马州中部县的山猫感染细胞球虫属的可能性高 25.693 倍。在已知蜱传播媒介最常见的县，细胞球虫属感染的流行率估计更高。根据 13 个样本，来自德克萨斯州西北部的山猫中细胞球虫属的发生频率为 30.8%（95%CI，12.4%-58.0%）。本研究的结果支持利用山猫作为监测动物来识别有感染细胞球虫属风险的地理区域。
