Toronto Humane Society, Toronto, Canada.
Ontario Veterinary College, Guelph, Canada.
J Feline Med Surg. 2021 Dec;23(12):1192-1199. doi: 10.1177/1098612X211005301. Epub 2021 Apr 13.
The aim of this study was to optimize the diagnosis of feline panleukopenia virus (FPV) infection in a shelter setting by: (1) comparing the results of the canine parvovirus IDEXX SNAP Parvo (SNAP) point-of-care ELISA with a commercial FPV quantitative real-time PCR (qPCR) test; (2) assessing whether vomit and anal/rectal swabs could be used for early diagnosis; and (3) clarifying the interpretation of weak-positive SNAP test results.
The study included shelter cats and kittens with incomplete or unknown vaccination history that had clinical signs suspicious for feline panleukopenia and fecal SNAP and PCR tests performed within 24 h of onset. Feces, anal/rectal swabs and vomit were tested using SNAP and PCR, with fecal PCR utilized as the reference standard.
One hundred and forty-five cats were included. Seventeen were diagnosed with FPV infection and 62 were negative; 66 could not be individually designated because they were co-housed. Sensitivity was as follows: fecal SNAP 55% (n = 102; 95% confidence interval [CI] 32-77); swab SNAP 30% (n = 55; 95% CI 7-65); swab PCR 77% (n = 55; 95% CI 46-95); and vomit PCR 100% (n = 17; 95% CI 16-100). Specificity was high (96-100%) for all sample and test types. For PCR-positive fecal samples, true-positive SNAP tests (including weak positives) had significantly higher DNA viral copy numbers than false-negative SNAP tests ( = 0.0031).
The SNAP ELISA should be viewed as an initial diagnostic test to rule in feline panleukopenia. Positive fecal SNAP test results, including weak positives, are highly likely to be true positives in clinically affected animals. Negative results in clinically affected animals are unreliable and should be followed up with PCR testing.
本研究旨在通过以下方式优化收容所中猫泛白细胞减少症病毒（FPV）感染的诊断：（1）比较犬细小病毒 IDEXX SNAP Parvo（SNAP）即时检验点酶联免疫吸附试验（ELISA）与商业 FPV 定量实时 PCR（qPCR）检测的结果；（2）评估呕吐物和肛门/直肠拭子是否可用于早期诊断；（3）阐明对弱阳性 SNAP 检测结果的解释。
本研究纳入了临床症状疑似猫泛白细胞减少症且粪便 SNAP 和 PCR 检测在发病后 24 小时内完成的未完全接种或未知疫苗接种史的收容所猫和小猫。使用 SNAP 和 PCR 检测粪便、肛门/直肠拭子和呕吐物，粪便 PCR 作为参考标准。
共纳入 145 只猫。17 只被诊断为 FPV 感染，62 只为阴性；66 只因共居而无法单独指定。敏感性如下：粪便 SNAP 为 55%（n=102；95%置信区间 [CI] 32-77）；拭子 SNAP 为 30%（n=55；95% CI 7-65）；拭子 PCR 为 77%（n=55；95% CI 46-95）；呕吐物 PCR 为 100%（n=17；95% CI 16-100）。所有样本和检测类型的特异性均较高（96-100%）。对于 PCR 阳性的粪便样本，真阳性 SNAP 检测（包括弱阳性）的 DNA 病毒拷贝数明显高于假阴性 SNAP 检测（=0.0031）。
SNAP ELISA 应视为一种初始诊断检测方法，用于排除猫泛白细胞减少症。在临床受影响的动物中，阳性粪便 SNAP 检测结果（包括弱阳性）极有可能为真阳性。在临床受影响的动物中，阴性结果不可靠，应通过 PCR 检测进行随访。
