Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.
Center for Surveillance, Immunization and Epidemiologic Research, National Institute of Infectious Diseases, Tokyo, Japan.
J Med Virol. 2023 Jun;95(6):e28886. doi: 10.1002/jmv.28886.
Hepatitis E virus (HEV) is an emerging causative agent of acute hepatitis. To clarify the epidemiology of HEV and characterize the genetic diversity of the virus in Japan, nationwide enhanced surveillance and molecular characterization studies of HEV in Japan were undertaken from 2014 to 2021. In total, 2770 hepatitis E cases were reported, of which 88% were domestic cases, while only 4.1% represented cases following infection abroad. In addition, 57% of domestic infections occurred in males aged in their 40s-70s. For domestic cases, infection via pork meat consumption continued to be the most reported route. Analysis of the 324 sequences detected between 2016 and 2021 showed that the majority of domestic HEV strains belong to Genotype 3a (G3a) and G3b. In contrast, six of eight cases of G1 HEV reflected infection abroad. Our results suggest that HEV is circulating widely in Japan, with genotypes G3a and G3b being most prevalent. Continued surveillance is necessary to monitor future trends and changes in the epidemiology of HEV in Japan.
戊型肝炎病毒（HEV）是一种新兴的急性肝炎病原体。为了阐明日本的 HEV 流行病学，并对该病毒的遗传多样性进行特征描述，2014 年至 2021 年在日本开展了全国性的增强监测和分子特征研究。共报告了 2770 例戊型肝炎病例，其中 88%为本地病例，而仅有 4.1%的病例是境外感染。此外，57%的本地感染发生在 40 多岁至 70 多岁的男性中。对于本地病例，猪肉消费导致的感染仍是报告最多的途径。对 2016 年至 2021 年检测到的 324 个序列进行分析表明，大多数本地 HEV 株属于基因型 3a（G3a）和 G3b。相比之下，8 例 G1 HEV 中有 6 例反映了境外感染。我们的结果表明，HEV 在日本广泛传播，其中 G3a 和 G3b 基因型最为流行。需要继续监测以监测日本未来 HEV 流行病学的趋势和变化。
