Mori Yoshio, Miyoshi Masahiro, Kikuchi Masayuki, Sekine Masao, Umezawa Masahiro, Saikusa Miwako, Matsushima Yuki, Itamochi Masae, Yasui Yoshihiro, Kanbayashi Daiki, Miyoshi Tatsuya, Akiyoshi Kyoko, Tatsumi Chika, Zaitsu Shuichi, Kadoguchi Mayumi, Otsuki Noriyuki, Okamoto Kiyoko, Sakata Masafumi, Komase Katsuhiro, Takeda Makoto
Department of Virology 3, National Institute of Infectious DiseasesTokyo, Japan.
Hokkaido Institute of Public HealthSapporo, Japan.
Front Microbiol. 2017 Aug 9;8:1513. doi: 10.3389/fmicb.2017.01513. eCollection 2017.
A nationwide rubella epidemic occurred from 2012 to 2013 in Japan, resulting in around 17,000 rubella cases and the birth of 45 infants with congenital rubella syndrome. The aim of this study was to genetically characterize the rubella viruses (RVs) circulating around the time of the epidemic in Japan. In total, 221 RV strains detected from 14 prefectures in Japan between 2010 and 2014 were sequenced in the 739 nucleotide-window region within the gene. The virus strains were chronologically and geographically characterized into groups based on phylogenetic analysis. Among the 221 strains analyzed, 192 (87%), 26 (12%), and 3 (1%) strains were classified into genotypes 2B, 1E, and 1J, respectively. The majority ( = 184) of the genotype 2B strains belonged to lineage 2B-L1 and shared nucleotide homology with the strains detected in Southeast and East Asian countries. Phylogenetic analyses demonstrated that at least six distinct clusters of RV strains (clusters 1-6) induced outbreaks in Japan between 2010 and 2014. Among them, strains from clusters 3, 4, and 6 circulated almost simultaneously during 2012-2013. The cluster 3 strains circulated locally, whereas strains from cluster 4 spread nationwide. The findings suggest that RVs were introduced into Japan many times from neighboring countries. The 2012-2013 epidemic was a complex of outbreaks induced by at least three clusters of RV strains.
2012年至2013年期间，日本发生了全国性风疹疫情，导致约17000例风疹病例，并出现了45例先天性风疹综合征婴儿。本研究的目的是对日本疫情期间流行的风疹病毒（RV）进行基因特征分析。2010年至2014年期间，从日本14个县检测到的221株RV毒株在基因的739个核苷酸窗口区域进行了测序。根据系统发育分析，按时间和地理顺序将病毒毒株分为不同组。在分析的221株毒株中，192株（87%）、26株（12%）和3株（1%）分别被归类为2B、1E和1J基因型。大多数（n = 184）2B基因型毒株属于2B-L1谱系，与在东南亚和东亚国家检测到的毒株具有核苷酸同源性。系统发育分析表明，2010年至2014年期间，至少六个不同的RV毒株簇（簇1-6）在日本引发了疫情。其中，簇3、4和6的毒株在2012年至2013年期间几乎同时传播。簇3的毒株在当地传播，而簇4的毒株则传播到全国。研究结果表明，RV多次从邻国传入日本。2012年至2013年的疫情是由至少三个RV毒株簇引发的疫情复合体。
