The clinical and virologic features of hepatitis E virus (HEV) infection seem to vary among regions even in developed countries. However, we have little information on the diversity of HEV infection. Here, we investigated the characteristics of 26 patients in our hospital located in Tochigi prefecture, 90 km north of Tokyo, between 2000 and 2019. The reported number of patients with acute hepatitis E is increasing in Japan because measurement of IgA‐class anti‐HEV antibody was commercially available from 2011. In contrast, the numbers at our hospital were 1.5/y and 1.0/y in 2000 to 2011 and 2012 to 2019, respectively. This is attributed to the fact that we have been investigating HEV as a cause of unknown hepatitis before 2011. Among isolated HEV subgenotypes, including 3a, 3b, 4b, 4c, and 4d, all three patients with subgenotype 4c infection presented acute liver failure. Four HEV strains shared more than or equal to 99% identity within the 412‐nucleotide partial sequence, in which the time and place of HEV infection varied, except for one intrafamilial infection. In addition, some strains were similar to HEV strains isolated far from Tochigi prefecture. In conclusion, the number of patients with acute hepatitis E was not increasing at Jichi Medical University Hospital and some strains were found to circulate in Japan.

中文翻译：

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2000年至2019年日本某大学医院戊型肝炎病毒感染的临床和病毒学特征。


即使在发达国家，戊型肝炎病毒（HEV）感染的临床和病毒学特征似乎也因地区而异。然而，我们对 HEV 感染多样性的信息很少。在这里，我们调查了 2000 年至 2019 年间位于东京以北 90 公里的栃木县的 26 名患者的特征。由于 IgA 类抗 HEV 的检测，日本报告的急性戊型肝炎患者数量正在增加抗体从2011年开始商业化。相比之下，我院2000年至2011年和2012年至2019年的数字分别为1.5/年和1.0/年。这归因于我们在2011年之前就一直在调查HEV作为不明肝炎的病因。在孤立的HEV亚基因型（包括3a、3b、4b、4c和4d）中，所有三名亚基因型4c感染的患者均出现急性肝功能衰竭。四种HEV毒株在412个核苷酸的部分序列中具有大于或等于99%的同一性，其中HEV感染的时间和地点各不相同，除了一种家庭内感染之外。此外，一些毒株与远离栃木县分离出的HEV毒株相似。总之，自治医科大学医院的急性戊型肝炎患者数量并未增加，并且发现一些菌株在日本传播。