Abstract

Background

Hepatitis E virus (HEV) is a major cause of acute viral hepatitis. Better understanding of HEV subtypes involved in hepatitis E infections is essential. Investigation of sources and routes of transmission and the identification of potential clusters/outbreaks rely upon molecular typing of viral strains. A study was carried out to evaluate the ability of laboratories to undertake molecular typing with genotype and subtype determination.

Methods

A blinded panel of 11 different Orthohepevirus A strains was distributed to 28 laboratories performing HEV sequence analysis. Laboratories used their routine HEV sequencing and genotyping methods.

Results

Results were returned by 25 laboratories. Overall, 93% samples were assigned to the correct genotype and 81% were assigned to the correct subtype. Fragments amplified for typing ranged in size and the sequencing assays targeted both the structural and non-structural protein-coding regions. There was good agreement between the reported sequences where methods targeted overlapping fragments. In some cases, incorrect genotypes/subtypes were reported, including those not contained in the panel, and in one case, a genotype was reported for a blinded control sample containing Zika virus; collectively these data indicate contamination problems.

Conclusions

In general, identification of genotypes was good; however, in a small number of cases, there was a failure to generate sequences from some of the samples. There was generally broad agreement between the use of online typing tools such as the one provided by HEVnet and curated lists of published HEV reference sequences; however, going forward harmonization between these resources is essential.

中文翻译：

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戊型肝炎病毒分子分型方法的评价

摘要

背景

戊型肝炎病毒（HEV）是急性病毒性肝炎的主要原因。更好地了解与戊型肝炎感染有关的 HEV 亚型至关重要。传播来源和途径的调查以及潜在集群/爆发的识别依赖于病毒株的分子分型。进行了一项研究，以评估实验室通过基因型和亚型确定进行分子分型的能力。

方法

将 11 种不同正乙肝病毒A 株的盲组分配给 28 个实验室进行 HEV 序列分析。实验室使用他们常规的 HEV 测序和基因分型方法。

结果

结果由 25 个实验室返回。总体而言，93% 的样本被分配到正确的基因型，81% 的样本被分配到正确的亚型。用于分型的扩增片段大小不等，测序分析针对结构和非结构蛋白质编码区。报告的序列之间有很好的一致性，其中方法针对重叠片段。在某些情况下，报告了不正确的基因型/亚型，包括未包​​含在面板中的那些，在一种情况下，报告了含有寨卡病毒的盲控对照样本的基因型；这些数据共同表明存在污染问题。

结论

总的来说，基因型的鉴定是好的；但是，在少数情况下，无法从某些样本中生成序列。使用在线打字工具（例如 HEVnet 提供的工具）与已发布的 HEV 参考序列的精选列表之间普遍存在广泛共识；然而，推动这些资源之间的协调是必不可少的。