Abstract:
Rift Valley fever (RVF) is a re-emerging vector-borne zoonosis with a high public health and veterinary impact. In West Africa, many lineages were previously detected, but since 2020, lineage H from South Africa has been the main cause of the outbreaks. In this study, clinical samples collected through national surveillance were screened for RVF virus (RVFV) acute infection by RT-PCR and IgM ELISA tests. Sequencing, genome mapping and in vitro phenotypic characterization in mammal cells were performed on RT-PCR positive samples in comparison with other epidemic lineages (G and C). Four RVFV human cases were detected in Senegal and the sequence analyses revealed that the strains belonged to lineage H. The in vitro kinetics and genome mapping showed different replication efficiency profiles for the tested RVFV lineages and non-conservative mutations, which were more common to lineage G or specific to lineage H. Our findings showed the re-emergence of lineage H in Senegal in 2022, its high viral replication efficiency in vitro and support the findings that genetic diversity affects viral replication. This study gives new insights into the biological properties of lineage H and calls for deeper studies to better assess its potential to cause a future threat in Senegal.
摘要:
裂谷热(RVF)是一种重新出现的媒介传播的人畜共患病,对公共卫生和兽医有很高的影响。在西非,以前检测到许多谱系,但自2020年以来,来自南非的血统H一直是疫情爆发的主要原因。在这项研究中,通过国家监测收集的临床样本通过RT-PCR和IgMELISA检测筛选RVF病毒(RVFV)急性感染.测序,与其他流行谱系(G和C)相比,对RT-PCR阳性样本进行了哺乳动物细胞的基因组作图和体外表型鉴定.在塞内加尔检测到4例RVFV人类病例,序列分析表明这些菌株属于H系。体外动力学和基因组作图显示,所测试的RVFV谱系和非保守突变的复制效率不同,我们的研究结果表明,2022年塞内加尔重新出现了谱系H,其在体外具有很高的病毒复制效率,并支持遗传多样性影响病毒复制的发现。这项研究为谱系H的生物学特性提供了新的见解,并呼吁进行更深入的研究,以更好地评估其在塞内加尔造成未来威胁的潜力。