Abstract:
The African horse sickness virus (AHSV) belongs to the Genus Orbivirus, family Sedoreoviridae, and nine serotypes of the virus have been described to date. The AHSV genome is composed of ten linear segments of double-stranded (ds) RNA, numbered in decreasing size order (Seg-1 to Seg-10). Genome segment 2 (Seg-2) encodes outer-capsid protein VP2, the most variable AHSV protein and the primary target for neutralizing antibodies. Consequently, Seg-2 determines the identity of the virus serotype. An African horse sickness (AHS) outbreak in an AHS-free status country requires identifying the serotype as soon as possible to implement a serotype-specific vaccination program. Considering that nowadays \'polyvalent live attenuated\' is the only commercially available vaccination strategy to control the disease, field and vaccine strains of different serotypes could co-circulate. Additionally, in AHS-endemic countries, more than one serotype is often circulating at the same time. Therefore, a strategy to rapidly determine the virus serotype in an AHS-positive sample is strongly recommended in both epidemiological situations. The main objective of this study is to describe the development and validation of three triplex real-time RT-PCR (rRT-PCR) methods for rapid AHSV serotype detection. Samples from recent AHS outbreaks in Kenia (2015-2017), Thailand (2020), and Nigeria (2023), and from the AHS outbreak in Spain (1987-1990), were included in the study for the validation of these methods.
摘要:
非洲马病病毒(AHSV)属于Orbivirus,Sedoreoviridae科,迄今为止,已经描述了该病毒的9种血清型。AHSV基因组由双链(ds)RNA的十个线性片段组成,按尺寸递减顺序编号(Seg-1到Seg-10)。基因组片段2(Seg-2)编码外衣壳蛋白VP2,最可变的AHSV蛋白和中和抗体的主要靶标。因此,Seg-2确定病毒血清型的身份。在无AHS状态的国家爆发非洲马病(AHS),需要尽快确定血清型,以实施血清型特异性疫苗接种计划。考虑到目前“多价减毒活疫苗”是控制该疾病的唯一市售疫苗接种策略,不同血清型的田间和疫苗株可以共同循环。此外,在AHS流行国家,多于一种血清型通常同时循环。因此,在两种流行病学情况下,强烈建议采用快速确定AHS阳性样本中病毒血清型的策略.本研究的主要目的是描述用于快速AHSV血清型检测的三种三重实时RT-PCR(rRT-PCR)方法的开发和验证。来自肯尼亚最近的AHS暴发(2015-2017)的样本,泰国(2020年),尼日利亚(2023年),来自西班牙的AHS爆发(1987-1990),被包括在这些方法的验证研究中。