Southeastern Cooperative Wildlife Disease Study, University of Georgia, Athens, GA, USA.
Departments of Population Health, University of Georgia, Athens, GA, USA.
J Vet Diagn Invest. 2023 Jul;35(4):399-403. doi: 10.1177/10406387231170795. Epub 2023 Apr 27.
The effects of filter paper strip (FPS) storage time and temperature on antibody detection are poorly understood despite widespread use in wildlife research. We collected sera and FPSs from 23 wild turkeys () and 20 northern bobwhites () experimentally infected with West Nile virus (WNV) to compare FPS storage methods with WNV plaque reduction neutralization test (PRNT) sensitivity. FPS storage methods included: immediate elution after drying, and storage at -20°C for 3 mo, -20°C for 6 mo, room temperature (RT) for 3 mo, and RT for 6 mo prior to elution. FPS eluates and sera were co-titrated to determine endpoint antibody titers, which were compared between FPS sera eluted immediately and sera, and among FPS eluates that underwent different storage conditions. Antibody titers were ~4-fold less in FPS sera eluted immediately versus sera, and dropped more frequently below PRNT detection threshold in northern bobwhites, which had ~10-fold lower serum antibody titers than wild turkeys. Antibody titers were lower in FPS samples stored at RT and for 6 mo. WNV serologic surveys may result in falsely low seroprevalence estimates if FPSs are stored at RT for ≥ 3 mo before elution.
尽管滤纸条（FPS）在野生动物研究中被广泛使用，但人们对其储存时间和温度对抗体检测的影响知之甚少。我们从 23 只野生火鸡（）和 20 只北方鹌鹑（）中收集了血清和 FPS，这些动物经实验感染了西尼罗河病毒（WNV），以比较 FPS 储存方法与 WNV 噬斑减少中和试验（PRNT）的敏感性。FPS 的储存方法包括：干燥后立即洗脱，以及在-20°C 下储存 3 个月、在-20°C 下储存 6 个月、在室温（RT）下储存 3 个月，以及在洗脱前在 RT 下储存 6 个月。将 FPS 洗脱液和血清共同滴定以确定终点抗体滴度，并比较 FPS 血清立即洗脱与血清之间以及经历不同储存条件的 FPS 洗脱液之间的滴度。与血清相比，立即洗脱的 FPS 血清中的抗体滴度低约 4 倍，在北方鹌鹑中更频繁地降至 PRNT 检测阈值以下，北方鹌鹑的血清抗体滴度比野生火鸡低约 10 倍。在 RT 下储存和储存 6 个月的 FPS 样本中的抗体滴度较低。如果在洗脱前将 FPS 在 RT 下储存≥3 个月，WNV 血清学调查可能导致假低血清阳性率估计。
