Publications by authors named "Masakazu Umemoto"
Human rotavirus strains having the unconventional G3P[6] genotype have been sporadically detected in diarrheic patients in different parts of the world. However, the full genomes of only three human G3P[6] strains from Asian countries (China, Indonesia, and Vietnam) have been sequenced and characterized, and thus the exact origin and evolution of G3P[6] strains in Asia remain to be elucidated. Here, we sequenced and characterized the full genome of a G3P[6] strain (RVA/Human-wt/JPN/SO1199/2020/G3P[6]) found in a stool sample from a 3-month-old infant admitted with acute gastroenteritis in Japan.
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- In 2018, unique G9P[8]-E2 human rotaviruses were found in children with diarrhea in various regions of Japan, including Tokyo.
- Researchers analyzed the genomes of seven G9P[8]-E2 strains and found a distinct genetic structure, combining elements from different rotavirus strains.
- The study indicates that these G9P[8]-E2 strains emerged from a reassortment of existing rotavirus strains and suggests a common origin due to their nearly identical genome sequences.
Article Synopsis
- - The study analyzed 2,348 death cases of children and adolescents in Japan from 2014 to 2016, finding that 18.2%-21.0% of deaths were identified based on demographic surveys, with 27.2% resulting from external factors or unknown causes.
- - The review indicated a notable proportion of preventable deaths (25%) and suggested the need for better evaluation of suspected child maltreatment cases, which accounted for 5%.
- - Challenges were identified in establishing a comprehensive Child Death Review system due to the high volume of cases and the need for improved verification processes across various organizations.
The emergence of unusual DS-1-like intergenogroup reassortant rotaviruses with a bovine-like G8 genotype (DS-1-like G8P[8] strains) has been reported in several Asian countries. During the rotavirus surveillance program in Japan in 2017, a DS-1-like G8P[8] strain (RVA/Human-wt/JPN/SO1162/2017/G8P[8]) was identified in 43 rotavirus-positive stool samples. Strain SO1162 was shown to have a unique genotype constellation, including genes from both genogroup 1 and 2: G8-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2.
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- - Recent reports indicate the emergence of new DS-1-like G3 rotaviruses, specifically the G3P[8] strains, found in children with severe diarrhea in Japan during the 2015-2016 rotavirus surveillance.
- - Researchers sequenced and analyzed the full genomes of three identified strains, which exhibited a unique combination of genes from different genogroups, specifically G3-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2.
- - Phylogenetic analysis suggested that these strains are reassortants, having acquired genetic material from equine G3 rotaviruses while maintaining a genetic backbone from DS-1-like G1P[8]
In Japan, monovalent and pentavalent rotavirus (RV) vaccines were approved in 2011 and 2012, respectively. To monitor changes in the RV genotypes before and after vaccine introduction, we performed a prospective observational study among children (＜ 5 years) with gastroenteritis who tested RV-positive on antigen rapid tests. Stool samples were collected from 3 different sites in Japan: Tsu City, Mie Prefecture; Kurashiki City, Okayama Prefecture; and Isumi City, Chiba Prefecture.
View Article and Find Full Text PDFRotavirus vaccine and health-care utilization for rotavirus gastroenteritis in Tsu City, Japan.
Western Pac Surveill Response J
May 2017
Background: Rotavirus vaccines were introduced in Japan in November 2011. We evaluated the subsequent reduction of the health-care burden of rotavirus gastroenteritis.
Methods: We conducted active surveillance for rotavirus gastroenteritis among children under 5 years old before and after the vaccine introduction.