Key result
Novel mono-reassortant G9P[8]-E2 rotavirus strain emerges to account for ~29% of Tokyo cases.
Why the study?
Rotavirus A (RVA) has been detected in patients with gastroenteritis even after vaccine introduction in Japan, prompting investigation of circulating RVA strains.
Observational (n=71)
Yes
A novel mono-reassortant G9P[8]-E2 rotavirus strain has emerged and begun spreading in Tokyo, Japan, highlighting the need for ongoing genomic surveillance.
Supports expanded rotavirus surveillance; leaves open effects on vaccine efficacy or disease severity.
Rotavirus A (RVA) has been detected in patients with gastroenteritis even after vaccine introduction in Japan. To investigate circulating RVA strains, RVA-positive stool specimens obtained in Tokyo in 2017 and 2018 were analyzed using next-generation sequencing. A total of 50 and 21 RVA samples were obtained in 2017 and 2018, respectively. In 2017, G2P[4] (40.0%) was the most prevalent strain, followed by G3P[8] (DS-1-like) (28.0%), G8P[8] (10.0%), G3P[8] (Wa-like) (8.0%), G9P[8]-E1 (8.0%), and mixed infection (6.0%). In 2018, G3P[8] (DS-1-like) (28.6%) and G9P[8]-E2 (28.6%) were the most prevalent strains, followed by G9P[8]-E1 (19.0%), G2P[4] (9.5%), G8P[8] (9.5%), and mixed infection (4.8%). Six G9P[8]-E2 strains detected in 2018 showed an atypical genotype constellation (G9P[8]-I1-R1-C1-M1-A1-N1-T1-E2-H1), which had not been reported previously. Phylogenetic analyses suggested that the RVA virus was generated by inter-genogroup reassortment between commonly circulating G9P[8] and G2P[4] strains in Japan. The G9P[8] strain seemed to be reassorted with only the NSP4 gene of the E2 genotype of the G2P[4] strain. Since this newly-emerged G9P[8]-E2 virus was detected in different locations in Tokyo, the virus appears to have already begun to spread to a wider area.
No takes yet. Share an insight, caveat, or question.
Fujii et al. (2019) conducted an observational in Rotavirus A gastroenteritis (n=71). Rotavirus A strains (including novel G9P[8]-E2) was evaluated on Genotype distribution and molecular characteristics of Rotavirus A strains. Next-generation sequencing of 71 Rotavirus A samples from Tokyo in 2017-2018 identified the emergence of a novel mono-reassortant G9P[8]-E2 strain, accounting for 28.6% of cases in 2018.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: