METHODS: A systematic review including the current evidence related to different variants of SARS-CoV-2 and the related morbidity and mortality was conducted through a systematic search utilizing the keywords in the online databases including Scopus, PubMed, Web of Science, and Science Direct; we retrieved all related papers and reports published in English from December 2019 to September 2020.
RESULTS: A review of identified articles has shown three main genomic variants, including type A, type B, and type C. we also identified three clades including S, V, and G. Studies have demonstrated that the C14408T and A23403G alterations in the Nsp12 and S proteins are the most prominent alterations in the world, leading to life-threatening mutations.The spike D614G amino acid change has become the most common variant since December 2019. From missense mutations found from Gujarat SARS-CoV-2 genomes, C28854T, deleterious mutation in the nucleocapsid (N) gene was significantly associated with patients\' mortality. The other significant deleterious variant (G25563T) is found in patients located in Orf3a and has a potential role in viral pathogenesis.
CONCLUSIONS: Overall, researchers identified several SARS-CoV-2 variants changing clinical manifestations and increasing the transmissibility, morbidity, and mortality of COVID-19. This should be considered in current practice and interventions to combat the pandemic and prevent related morbidity and mortality.
方法:通过利用包括Scopus在内的在线数据库中的关键词进行系统搜索,包括与SARS-CoV-2的不同变体以及相关发病率和死亡率有关的当前证据。PubMed,WebofScience,和ScienceDirect;我们检索了2019年12月至2020年9月以英文发表的所有相关论文和报告。
结果:对已鉴定文章的综述显示了三种主要的基因组变异,包括A型,B型,和C型,我们还确定了三个分支,包括S,V,和G.研究表明,Nsp12和S蛋白中的C14408T和A23403G改变是世界上最突出的改变,导致危及生命的突变.自2019年12月以来,峰值D614G氨基酸变化已成为最常见的变体。从古吉拉特邦SARS-CoV-2基因组中发现的错义突变,C28854T,核衣壳(N)基因的有害突变与患者死亡率显着相关。另一个显著的有害变体(G25563T)在位于Orf3a的患者中发现,并且在病毒发病机理中具有潜在作用。
结论:总体而言,研究人员发现了几种SARS-CoV-2变种改变临床表现并增加传播性,发病率,和COVID-19的死亡率。在当前的实践和干预措施中应考虑到这一点,以抗击大流行并预防相关的发病率和死亡率。