Variation of human norovirus GII genotypes detected in Ibaraki, Japan, during 2012–2018

Gut Pathogens

Akihide Ryo¹  Nobuya Sasaki²  Jumpei Aso³  Kaori Okayama³  Hirokazu Kimura³  Takumi Motoya⁴  Setsuko Fukaya⁴  Keiko Goto⁴  Ikuko Doi⁴  Yoshiaki Ikeda⁴  Noriko Nagata⁴  Aoi Saito⁴  Masahiro Umezawa⁴  Yuki Matsushima⁵  Kazuhiko Katayama⁶  Taisei Ishioka⁷ 

[1] Department of Molecular Biodefence Research, Yokohama City University Graduate School of Medicine;Faculty of Veterinary Medicine, Kitasato University;Gunma Paz University Graduate School of Health Science;Ibaraki Prefectural Institute of Public Health;Kawasaki City Institute for Public Health;Laboratory of Viral Infection I, Kitasato Institute for Life Sciences, Kitasato University;Takasaki City Public Health Center;

关键词: Epidemiology;    Genotype;    Norovirus;    Outbreak;    Viral load;   

DOI  :  10.1186/s13099-019-0303-z

来源: DOAJ

【 摘 要 】

Abstract Background Human norovirus (HuNoV) is the major cause of viral acute gastroenteritis for all age groups in various countries. HuNoV GII in particular accounted for the majority of norovirus outbreaks, among which GII.4 caused repeated outbreaks for a long time. Besides GII.4, other norovirus genotypes, GII.2, GII.6, and GII.17, have also been prevalent in various contexts in recent years, but few detailed epidemiological studies of them have been performed and are poorly understood. We thus conducted an epidemiological analysis of HuNoV GII in Ibaraki Prefecture, Japan, by performing surveillance in the six seasons from September 2012 to August 2018. Results HuNoV GI occurred almost sporadically for all genotypes; however, each genotype of GII exhibited its typical epidemiological characteristics. Although the number of outbreaks of GII.4 decreased season by season, it reemerged in 2017/2018 season. The timing of the epidemic peak in terms of number of cases for GII.17 differed from that for the other genotypes. The patients age with GII.2 and GII.6 were younger and outbreak of GII.17 occurred frequently as food poisoning. Namely, the primarily infected outbreak group differed for each genotype of HuNoV GII. Moreover, the viral load of patients differed according to the genotype. Conclusions Various HuNoV genotypes including GII.2, GII.4, GII.6, and GII.17 were shown to be associated with various types of outbreak sites (at childcare and educational facilities, involving cases of food poisoning, and at elderly nursing homes) in this study. These genotypes emerged in recent years, and their prevalence patterns differed from each other. Moreover, differences in outbreak sites and viral load of patients among the genotypes were identified.

【 授权许可】

Unknown