Curry Patricia S, Elkin Brett T, Campbell Mitch, Nielsen Klaus, Hutchins Wendy, Ribble Carl, Kutz Susan J
Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
J Wildl Dis. 2011 Jan;47(1):12-20. doi: 10.7589/0090-3558-47.1.12.
We evaluated blood collected on Nobuto filter-paper (FP) strips for use in detecting Brucella spp. antibodies in caribou. Whole blood (for serum) and blood-saturated FP strips were obtained from 185 killed arctic caribou (Rangifer tarandus groenlandicus). Sample pairs (serum and FP eluates) were simultaneously tested in duplicate using competitive enzyme-linked immunosorbent assay (c-ELISA) and indirect ELISA (i-ELISA) for Brucella spp. Prior work based on isolation of Brucella spp. revealed sensitivity (SE) and specificity (SP) of 100% and 99%, respectively, for both these serum assays in caribou. Infection status of the animals in the current study was unknown but recent sampling had revealed clinical brucellosis and >40% Brucella antibody prevalence in the herd. To assess the performance of FP relative to serum in these assays, serum was used as the putative gold standard. On both assays, the findings for duplicate runs (A and B) were similar. For c-ELISA run A, the FP Brucella prevalence (47%) was lower than serum prevalence (52%), with SE 89% (95% confidence interval [CI]: 82-95%) and SP 99% (97-100%). For i-ELISA run A, serum and FP Brucella prevalence rates were identical (43%), and the SE and SP of FP testing were 100% and 99% (97-100%), respectively. The findings suggest better FP test performance with i-ELISA than with c-ELISA; however, i-ELISA does not distinguish cross-reacting antibodies induced by Brucella vaccination or exposure to certain other Gram-negative pathogens. Results for duplicate FP eluates (prepared using separate FP strips from each animal) were strongly correlated for both protocols (r=0.996 and 0.999 for c-ELISA and i-ELISA, respectively), indicating minimal variability among FPs from any individual caribou. Dried caribou FP blood samples stored for 2 mo at room temperature are comparable with serum for use in Brucella spp. c-ELISA and i-ELISA. Hunter-based FP sampling can facilitate detection of disease exposure in remote regions and under adverse conditions, and can expand wildlife disease surveillance across temporospatial scales.
我们评估了用于检测北美驯鹿布鲁氏菌属抗体的野本滤纸（FP）条上采集的血液。从185头被猎杀的北极驯鹿（Rangifer tarandus groenlandicus）身上获取全血（用于制备血清）和血液饱和的FP条。样本对（血清和FP洗脱液）使用布鲁氏菌属竞争酶联免疫吸附测定（c-ELISA）和间接酶联免疫吸附测定（i-ELISA）同时进行一式两份检测。之前基于布鲁氏菌属分离的研究表明，这两种血清检测方法在驯鹿中的灵敏度（SE）和特异性（SP）分别为100%和99%。本研究中动物的感染状况未知，但近期采样显示该鹿群存在临床布鲁氏菌病且布鲁氏菌抗体患病率>40%。为评估在这些检测中FP相对于血清的性能，将血清用作假定的金标准。在两种检测中，一式两份检测结果（A和B）相似。对于c-ELISA检测A，FP布鲁氏菌患病率（47%）低于血清患病率（52%），SE为89%（95%置信区间[CI]：82 - 95%），SP为99%（97 - 100%）。对于i-ELISA检测A，血清和FP布鲁氏菌患病率相同（43%），FP检测的SE和SP分别为100%和99%（97 - 100%）。研究结果表明，i-ELISA检测中FP的性能优于c-ELISA；然而，i-ELISA无法区分由布鲁氏菌疫苗接种或接触某些其他革兰氏阴性病原体诱导的交叉反应抗体。两种检测方法中，一式两份FP洗脱液（使用每只动物单独的FP条制备）的结果相关性很强（c-ELISA和i-ELISA的r分别为0.996和0.999），表明来自任何一只北美驯鹿的FP之间变异性最小。在室温下储存2个月的干燥北美驯鹿FP血样在布鲁氏菌属c-ELISA和i-ELISA检测中与血清相当。基于猎人的FP采样有助于在偏远地区和不利条件下检测疾病暴露情况，并可在时空尺度上扩大野生动物疾病监测范围。
