Adjadj Nadjah Radia, Vicca Jo, Michiels Rodolphe, De Regge Nick
Unit of Enzootic, Vector-Borne and Bee Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium.
Odisee vzw, University College KULeuven, campus Sint-Niklaas, Hospitaalstraat 23, 9100 Sint-Niklaas, Belgium.
Viruses. 2019 Dec 18;12(1):3. doi: 10.3390/v12010003.
Small ruminant lentivirus (SRLV) control programs are mainly based on diagnostic tests performed on blood samples collected from sheep and goats. Since blood sampling is costly and stressful for the animals, we evaluated whether milk could be used as an inexpensive and easily collectable matrix for SRLV detection. We therefore compared SRLV detection via two commercial enzyme-linked immunosorbent assays (ELISAs) and quantitative polymerase chain reaction (qPCR) in blood and corresponding milk samples from 321 goats originating from eight different SRLV-infected farms in Flanders (Belgium). The IDscreen ELISA had a better relative sensitivity (97% vs 93%) and specificity (100% and 97%) than the Elitest ELISA for SRLV-specific antibody detection in milk compared to serum. The higher sensitivity correlates with a 10-fold higher analytical sensitivity of the IDscreen test. In contrast to the overall good ELISA results, qPCR on milk cell pellets lacked sensitivity (81%) and specificity (88%), compared to molecular detection in blood leucocyte pellets. Our results show that serology is more suitable than qPCR for SRLV diagnosis, and that milk may represent an interesting matrix for a preliminary evaluation of a herd's infection status. Serum remains however the sample of choice for control programs where it is important to identify positive animals with the highest sensitivity.
小型反刍动物慢病毒(SRLV)防控计划主要基于对从绵羊和山羊采集的血样进行的诊断检测。由于采血对动物来说成本高昂且会造成应激,我们评估了牛奶是否可以作为一种廉价且易于采集的基质用于SRLV检测。因此,我们比较了通过两种商业酶联免疫吸附测定(ELISA)以及定量聚合酶链反应(qPCR)对来自比利时弗拉芒地区8个不同SRLV感染农场的321只山羊的血液和相应牛奶样本进行SRLV检测的情况。与血清相比,在牛奶中检测SRLV特异性抗体时,IDscreen ELISA比Elitest ELISA具有更高的相对灵敏度(分别为97%和93%)和特异性(分别为100%和97%)。更高的灵敏度与IDscreen检测高10倍的分析灵敏度相关。与总体良好的ELISA结果相反,与血液白细胞沉淀中的分子检测相比,牛奶细胞沉淀的qPCR缺乏灵敏度(81%)和特异性(88%)。我们的结果表明,血清学比qPCR更适合SRLV诊断,并且牛奶可能是初步评估畜群感染状况的一种有意义的基质。然而,在需要以最高灵敏度识别阳性动物的防控计划中,血清仍然是首选样本。