O'Keefe Jacinta, Tracy Lilly, Yuen Lilly, Bonanzinga Sara, Li Xin, Chong Brian, Nicholson Suellen, Jackson Kathy
Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
Front Microbiol. 2021 Feb 4;12:640325. doi: 10.3389/fmicb.2021.640325. eCollection 2021.
Hepatitis E virus (HEV) is a common cause of acute viral hepatitis with significant morbidity and mortality, particularly in pregnant women. There are four major genotypes which can cause disease in humans. Genotypes 1 and 2 are usually associated with outbreaks and spread via facal/oral route or contaminated water. Genotypes 3 and 4 are zoonotic and usually associated with handling of pigs or consumption of contaminated pork. The strains circulating in Australia have never been characterized.
RATIONALE/AIMS: The aims for this project are to identify the HEV genotypes found in Australia and link them to possible sources of transmission by phylogenetic analysis.
Between 2015 and 2020, 91 HEV isolates were sequenced and genotyped using an in-house PCR. Sixty-six of these were also sequenced by using the international HEVnet primers. Genotypes were determined using the BLASTn program. Relatedness to other strains in Australia was determined by phylogenetic analyses of the HEVnet sequences. Isolates were also stratified by state of origin, gender, age, predisposing factors and travel history (if known).
Of the 91 HEV isolates sequenced, 55 (60.4%) were genotype 1. There were 34 (37.4%) genotype 3 strains and two genotype 4 (2.2%). At least 20 of the genotype 1 strains have been linked to travel in India, and another three with Pakistan. Five of the "Indian" strains were closely related and are suspected to have originated in Gujarat. Phylogenetic analysis also showed that 12 genotype 3 strains were genetically related and potentially acquired in/from New South Wales, Australia. The two genotype 4 strains may have originated in China.
This is the first study to describe the HEV isolates identified in Australia. The results infer that HEV may be acquired during overseas travel as well as locally, presumably from consumption of pork or pork-related products. The phylogenetic analyses also reveal clusters of infection originating from India and Pakistan. This study provides some insight into the source and epidemiology of HEV infection in Australia which may be used to guide public health procedure and enable the implementation of measures to deal with potential outbreaks of infection.
戊型肝炎病毒（HEV）是急性病毒性肝炎的常见病因，发病率和死亡率较高，在孕妇中尤为明显。有四种主要基因型可导致人类发病。基因型1和2通常与疫情暴发有关，通过粪口途径或受污染的水传播。基因型3和4是人畜共患病型，通常与接触猪或食用受污染猪肉有关。在澳大利亚传播的毒株从未被鉴定过。
原理/目的：本项目的目的是鉴定在澳大利亚发现的HEV基因型，并通过系统发育分析将它们与可能的传播来源联系起来。
2015年至2020年期间，使用内部PCR对91株HEV分离株进行测序和基因分型。其中66株还使用国际HEVnet引物进行了测序。使用BLASTn程序确定基因型。通过对HEVnet序列进行系统发育分析，确定与澳大利亚其他毒株的亲缘关系。分离株还按来源州、性别、年龄、易感因素和旅行史（如已知）进行分层。
在测序的91株HEV分离株中，55株（60.4%）为基因型1。有34株（37.4%）基因型3毒株和2株基因型4毒株（2.2%）。至少20株基因型1毒株与在印度旅行有关，另外3株与巴基斯坦有关。5株“印度”毒株密切相关，怀疑起源于古吉拉特邦。系统发育分析还表明，12株基因型3毒株在基因上相关，可能是在澳大利亚新南威尔士州感染或从该州感染的。这2株基因型4毒株可能起源于中国。
这是第一项描述在澳大利亚鉴定出的HEV分离株的研究。结果表明，HEV可能在海外旅行期间以及在当地感染，推测是通过食用猪肉或猪肉相关产品感染的。系统发育分析还揭示了源自印度和巴基斯坦的感染集群。本研究为澳大利亚HEV感染的来源和流行病学提供了一些见解，可用于指导公共卫生程序，并使采取措施应对潜在的感染暴发成为可能。
