Circulated Echovirus 18 strains in Guangdong Province and worldwide: a novel perspective on genetic diversity and recombination patterns

Echovirus 18 (E18) has re-emerged as a global public health concern in recent years because of its association with severe neonatal systemic diseases that pose a risk of high mortality. The lack of effective intervention strategies for E18 infections is largely attributed to limited knowledge regarding molecular epidemiology and recombination patterns. In this study, we obtained seven full-length E18 sequences from infants in Guangdong Province and combined them with representative sequences from GenBank. Using this expanded dataset, we analyzed the molecular epidemiological features, genetic characteristics, and recombination patterns of E18. Global statistics reveal a distinct double-peak pattern in the frequency of E18 infections throughout the year in the Northern Hemisphere. All strains isolated from clinical specimens were classified as genotype C2, which has emerged as the predominant circulating strain in Guangdong Province and globally. Several potential recombination events with E30 were identified among these seven strains, particularly in the P2 and P3 non-structural regions. This study offers new insights into the global dissemination, genetic diversity, and phylodynamicsof E18, potentially providing valuable information for designing antiviral vaccines and the implementation of sustainable surveillance strategies to enhance virus prevention and control during public health crises.

埃可病毒18型（Echovirus 18，E18）近年来再度成为全球公共卫生关注的焦点议题，因其与可引发高致死风险的重症新生儿全身性疾病密切相关。当前针对E18感染缺乏有效干预手段，这在很大程度上归咎于人们对其分子流行病学（molecular epidemiology）特征与重组模式（recombination patterns）的认知局限。本研究从广东省婴幼儿样本中获取了7条全长E18序列，并结合从基因银行（GenBank）获取的代表性序列，构建了扩展后的数据集。基于该扩展数据集，我们分析了E18的分子流行病学特征、遗传特性及重组模式。全球统计数据显示，北半球的E18感染频率全年呈现显著的双峰分布格局。所有从临床标本中分离得到的毒株均被归类为基因型C2，该基因型现已成为广东省乃至全球范围内的优势流行毒株。在这7条毒株序列中，我们鉴定出多起与E30发生潜在重组的事件，尤其集中于P2与P3非结构区域。本研究为E18的全球传播、遗传多样性及系统发育动力学（phylodynamics）提供了全新的认知视角，有望为研发抗病毒疫苗、制定可持续监测策略以强化公共卫生危机期间的病毒防控工作提供极具价值的参考依据。