The mosquito-borne alphavirus o'nyong-nyong virus (ONNV) has proven its potential to cause major human outbreaks. On the African continent, ONNV causes unspecific febrile illness and co-circulates with the close relative chikungunya virus (CHIKV). The true scale of ONNV burden is poorly understood in Africa, because of the scarce availability of molecular in-house and commercial assays, strong cross-reactivity between ONNV and CHIKV in serological assays and a lack of surveillance. We designed a new RT-qPCR assay targeting the E1 gene for the detection of ONNV that can be used in monoplex or in duplex format, combined with a previously published CHIKV monoplex assay targeting the nsp1. The lower limit of detection with 95% positivity rate was determined to be <10 RNA copies/µL in monoplex and duplex format for both ONNV and CHIKV. Both monoplex assays and the duplex assay proved to be linear within the tested range of approximately 108 to 102 RNA copies/µl, and showed 100% specificity against a wide panel of arbovirus supernatants as well as several other pathogens in clinical samples. Testing of CHIKV positive serum and ONNV spiked plasma samples confirmed the suitability of the assays in a clinical setting. The new assays provide a robust tool for molecular ONNV as well as ONNV/CHIKV simultaneous detection and may contribute to clarify the true burden of the two viruses, to improve arbovirus surveillance and to strengthen epidemics preparedness in Africa.

中文翻译：

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用于检测和鉴定 o'nyong-nyong 和基孔肯雅热病毒的双重 RT-qPCR 检测的分析和临床评估。


蚊媒甲病毒 o'nyong-nyong 病毒 （ONNV） 已被证明其可能导致大规模人类暴发。在非洲大陆，ONNV 可引起非特异性发热性疾病，并与近亲基孔肯雅热病毒 （CHIKV） 共同传播。由于分子内部和商业检测稀缺、血清学检测中 ONNV 和 CHIKV 之间的强交叉反应性以及缺乏监测，非洲对 ONNV 负担的真实规模知之甚少。我们设计了一种靶向 E1 基因的新型 RT-qPCR 检测试剂盒，用于检测 ONNV，该检测试剂盒可用于单链或双链形式，并结合了先前发表的靶向 nsp1 的 CHIKV 单链检测。对于 ONNV 和 CHIKV，阳性率为 95% 的检测下限为 <10 RNA 拷贝/μL，单链和双链形式。单重检测和双重检测均被证明在大约 108 至 102 个 RNA 拷贝/μl 的测试范围内是线性的，并且对临床样品中的大量虫媒病毒上清液以及其他几种病原体显示出 100% 的特异性。CHIKV 阳性血清和 ONNV 加标血浆样本的检测证实了这些检测在临床环境中的适用性。新检测为分子 ONNV 以及 ONNV/CHIKV 同时检测提供了强大的工具，并可能有助于阐明这两种病毒的真正负担，改善虫媒病毒监测并加强非洲的流行病防范。