Chukwudi Ijeoma Chekwube, Ogbu Kenneth Ikejiofor, Luka Pam Dachung, Malesa Refiloe Petunia, Heath Livio Edward, Ugochukwu Emmanuel Ikenna, Chah Kennedy Foinkfu
Department of Veterinary Medicine, University of Nigeria Nsukka, Enugu State Nigeria.
Department of Animal Health, Federal College of Animal Health and Production Technology, National Veterinary Research Institute Vom, Plateau State, Nigeria.
Vet World. 2020 Nov;13(11):2358-2363. doi: 10.14202/vetworld.2020.2358-2363. Epub 2020 Nov 7.
Peste des petits ruminants (PPR) is an acute, extremely contagious transboundary viral disease of small ruminants with severe economic consequences, caused by PPR virus. Cost-effective and rapid diagnosis of the disease is essential for prompt management and control. This study aimed to compare the application of a commercial colorimetric loop-mediated isothermal amplification (cLAMP) kit and reverse transcriptase-polymerase chain reaction (RT-PCR) in the diagnosis of PPR in sheep and goats in Southeast Nigeria.
Nasal swab samples were collected from West African Dwarf sheep and goats showing clinical signs suggestive of PPR (n=80) and those without any clinical signs (n=140) of the disease. The diagnosis was achieved through detection of PPR viral genome in the samples using a cLAMP kit and RT-PCR. cLAMP assay was done directly on nasal swab samples without ribosomal nucleic acid extraction. A set of six primers targeting the matrix gene protein was used for the cLAMP assay.
PPR viral genome was detected by both cLAMP and RT-PCR in 51 (63.8%) of the 80 samples from sheep and goats with signs suggestive of PPR while 14 (10%) of those without signs tested positive for PPR by both assay methods. There was a 100% agreement in the cLAMP and RT-PCR results. However, cLAMP was a faster, easier, and less expensive method compared to RT-PCR.
The cLAMP assay demonstrates the potential for a point of care diagnosis in the field and a valuable diagnostic tool in areas with poor electricity supply as well as in a less equipped diagnostic laboratory. Since the reagents are affordable, cLAMP can be a diagnostic tool of choice in the detection and surveillance of PPR virus in countries with limited resources.
小反刍兽疫（PPR）是由小反刍兽疫病毒引起的一种急性、极具传染性的小反刍兽跨边境病毒性疾病，会造成严重的经济后果。对该疾病进行经济高效且快速的诊断对于及时管理和控制至关重要。本研究旨在比较一种商业比色环介导等温扩增（cLAMP）试剂盒与逆转录聚合酶链反应（RT-PCR）在尼日利亚东南部绵羊和山羊小反刍兽疫诊断中的应用。
从表现出疑似小反刍兽疫临床症状的西非矮种绵羊和山羊（n = 80）以及无任何该疾病临床症状的绵羊和山羊（n = 140）中采集鼻拭子样本。通过使用cLAMP试剂盒和RT-PCR检测样本中的小反刍兽疫病毒基因组来进行诊断。cLAMP检测直接在鼻拭子样本上进行，无需提取核糖体核酸。使用一组针对基质基因蛋白的六条引物进行cLAMP检测。
在80份来自有疑似小反刍兽疫症状的绵羊和山羊的样本中，51份（63.8%）通过cLAMP和RT-PCR均检测到小反刍兽疫病毒基因组，而在140份无症状样本中，14份（10%）通过两种检测方法均呈小反刍兽疫阳性。cLAMP和RT-PCR结果完全一致。然而，与RT-PCR相比，cLAMP是一种更快、更简便且成本更低的方法。
cLAMP检测显示出在现场进行即时诊断的潜力，对于电力供应差的地区以及设备简陋的诊断实验室而言是一种有价值的诊断工具。由于试剂价格实惠，cLAMP可成为资源有限国家检测和监测小反刍兽疫病毒的首选诊断工具。
