Arthropod-Borne Animal Diseases Research Unit, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS 66502, USA.
J Virol Methods. 2013 Nov;193(2):426-31. doi: 10.1016/j.jviromet.2013.07.006. Epub 2013 Jul 11.
Outbreaks of Rift Valley fever in Kenya, Madagascar, Mauritania, and South Africa had devastating effects on livestock and human health. In addition, this disease is a food security issue for endemic countries. There is growing concern for the potential introduction of RVF into non-endemic countries. A number of single-gene target amplification assays have been developed for the rapid detection of RVF viral RNA. This paper describes the development of an improved amplification assay that includes two confirmatory target RNA segments (L and M) and a third target gene, NSs, which is deleted in the Clone 13 commercial vaccine and other candidate vaccines. The assay also contains an exogenous RNA control added during the PCR setup for detection of amplification inhibitors. The assay was evaluated initially with samples from experimentally infected animals, after which clinical veterinary and human samples from endemic countries were tested for further evaluation. The assay has a sensitivity range of 66.7-100% and a specificity of 92.0-100% depending on the comparison. The assay has an overall sensitivity of 92.5%, specificity of 95% and a positive predictive value of 98.7%. The single-tube assay provides confirmation of the presence of RVFV RNA for improved confidence in diagnostic results and a "differentiate infected from vaccinated animals" (DIVA)--compatible marker for RVFV NSs--deleted vaccines, which is useful for RVF endemic countries, but especially important in non-endemic countries.
肯尼亚、马达加斯加、毛里塔尼亚和南非的裂谷热疫情对牲畜和人类健康造成了毁灭性影响。此外，这种疾病也是流行国家的粮食安全问题。人们越来越担心裂谷热病毒可能会传入非流行国家。已经开发出许多单基因靶标扩增检测方法，用于快速检测裂谷热病毒 RNA。本文描述了一种改进的扩增检测方法的开发，该方法包括两个确认性靶标 RNA 片段（L 和 M）和第三个靶标基因 NSs，该基因在克隆 13 商业疫苗和其他候选疫苗中被删除。该检测还包含在 PCR 设置过程中添加的外源性 RNA 对照，用于检测扩增抑制剂。该检测最初是用来自实验感染动物的样本进行评估的，然后对来自流行国家的临床兽医和人类样本进行了测试，以进一步评估。该检测的灵敏度范围为 66.7-100%，特异性为 92.0-100%，具体取决于比较。该检测的总灵敏度为 92.5%，特异性为 95%，阳性预测值为 98.7%。单管检测可确认裂谷热病毒 RNA 的存在，从而提高诊断结果的可信度，并为裂谷热 NSs 缺失疫苗提供“区分感染和接种动物”（DIVA）兼容标记，这对裂谷热流行国家有用，但在非流行国家尤为重要。
