Abstract
Background: Inter-genogroup reassortment of Rotavirus A (RVA)
strains has highlighted the spread of unusual RVA strains worldwide. We
previously reported the equine-like G3 RVA as predominant strains in
Indonesia in 2015-2016. However, since July 2017, typical human
genotypes G1 and G3 have replaced these strains completely. To
understand how dynamic changes in RVA occur in Indonesia, we performed a
detailed epidemiological study.
Main body: A total of 356 stool specimens were collected from
hospitalized children in Sidoarjo, Indonesia between 2018 and 2022.
Whole-genome sequencing was performed for all 26 RVA-positive samples
using next-generation sequencing. Twenty-four samples were determined to
be the unusual RVA G9P[4], while 2 were G9P[6]. Detailed
analysis revealed that seven G9P[4] strains had the typical
DS-1-like backbone, while the other strains exhibited a
double-reassortant profile (G9-N1) on the DS-1-like backbone.
The Bayesian evolutionary analyses suggested that the Indonesian
G9P[4] strains share a common ancestor with previously reported
G9P[4] strains in the VP7 and VP4 genes.
Conclusions: G9P[4] DS-1-like strains were identified as
the predominant genotype in Indonesia in 2021 for the first time. These
results suggest that the G9P[4] strains were generated from the
previous G9P[4] strains that had undergone further
intra-reassortments with the other circulating strains.
(200 words)