Nabakooza Grace, Galiwango Ronald, Frost Simon D W, Kateete David P, Kitayimbwa John M
Department of Immunology and Molecular Biology, Makerere University, Old Mulago Hill Road, P.O. Box 7072, Kampala 256, Uganda.
UVRI Centre of Excellence in Infection and Immunity Research and Training (MUII-Plus), Makerere University, Plot No: 51-59 Nakiwogo Road, P.O. Box 49, Entebbe 256, Uganda.
Microorganisms. 2022 Apr 25;10(5):900. doi: 10.3390/microorganisms10050900.
Genomic characterization of circulating influenza type-A viruses (IAVs) directs the selection of appropriate vaccine formulations and early detection of potentially pandemic virus strains. However, longitudinal data on the genomic evolution and transmission of IAVs in Africa are scarce, limiting Africa's benefits from potential influenza control strategies. We searched seven databases: African Journals Online, Embase, Global Health, Google Scholar, PubMed, Scopus, and Web of Science according to the PRISMA guidelines for studies that sequenced and/or genomically characterized Africa IAVs. Our review highlights the emergence and diversification of IAVs in Africa since 1993. Circulating strains continuously acquired new amino acid substitutions at the major antigenic and potential N-linked glycosylation sites in their hemagglutinin proteins, which dramatically affected vaccine protectiveness. Africa IAVs phylogenetically mixed with global strains forming strong temporal and geographical evolution structures. Phylogeographic analyses confirmed that viral migration into Africa from abroad, especially South Asia, Europe, and North America, and extensive local viral mixing sustained the genomic diversity, antigenic drift, and persistence of IAVs in Africa. However, the role of reassortment and zoonosis remains unknown. Interestingly, we observed substitutions and clades and persistent viral lineages unique to Africa. Therefore, Africa's contribution to the global influenza ecology may be understated. Our results were geographically biased, with data from 63% (34/54) of African countries. Thus, there is a need to expand influenza surveillance across Africa and prioritize routine whole-genome sequencing and genomic analysis to detect new strains early for effective viral control.
甲型流感病毒（IAV）的基因组特征有助于选择合适的疫苗配方，并早期检测潜在的大流行病毒株。然而，关于IAV在非洲的基因组进化和传播的纵向数据稀缺，限制了非洲从潜在的流感控制策略中获益。我们根据PRISMA指南，在七个数据库中进行了检索：非洲在线期刊、Embase、全球健康、谷歌学术、PubMed、Scopus和科学网，以查找对非洲IAV进行测序和/或基因组特征分析的研究。我们的综述突出了自1993年以来IAV在非洲的出现和多样化。流行毒株在其血凝素蛋白的主要抗原和潜在的N-糖基化位点不断获得新的氨基酸替换，这极大地影响了疫苗的保护作用。非洲IAV在系统发育上与全球毒株混合，形成了强大的时间和地理进化结构。系统发育地理分析证实，病毒从国外，特别是南亚、欧洲和北美迁移到非洲，以及广泛的本地病毒混合维持了IAV在非洲的基因组多样性、抗原漂移和持久性。然而，重配和人畜共患病的作用仍然未知。有趣的是，我们观察到了非洲特有的替换、分支和持续的病毒谱系。因此，非洲对全球流感生态的贡献可能被低估了。我们的结果存在地理偏差，来自63%（34/54）的非洲国家的数据。因此，有必要在整个非洲扩大流感监测，并优先进行常规全基因组测序和基因组分析，以便尽早检测新毒株，实现有效的病毒控制。
