Available online 25 May 2023, 105497

Author links open overlay panel, , , , , , , , AbstractBackground

Rotavirus group A (RVA) is a causative agent of acute gastroenteritis among young children worldwide, despite the global expansion of rotavirus vaccination. In Korea, although the prevalence of RVA has been reduced among young children owing to vaccination, nosocomial infections still occur among neonates.

Objectives

The aim of this study was to investigate the molecular epidemiology of RVA strains associated with several neonatal outbreaks in Seoul from 2017 to 2020.

Study design

Clinical and environmental samples were collected and screened for the presence of RVA using ELISA and PCR targeting VP6, respectively. RVA-positive strains were genotyped via RT-PCR and subsequent sequencing of VP4 and VP7 and were phylogenetically compared with RVA strains from other countries.

Results

During 2017-2020, a total of 15 RVA outbreaks occurred at neonatal facilities (six in hospital neonatal wards and nine in postpartum care centers) in Seoul, and only two RVA genotypes were detected: G4P[6] and G8P[6]. G8P[6] emerged in Seoul November 2018 and immediately became the predominant genotype among neonates, at least up to 2020. Phylogenetic analysis revealed that the G8P[6] genotype in this study was closely related to G8P[6] strains first identified in Korea in 2017, but differed from G8P[6] strains detected in Africa.

Conclusions

A novel G8P[6] genotype of RVA strains has emerged and caused outbreaks among neonates in Seoul. Continued surveillance for circulating RVA genotypes is imperative to monitor genotype changes and their potential risks to public health.

Section snippetsBackground

Rotavirus is a major cause of acute gastroenteritis among young children, and is estimated to be responsible for over 215 000 deaths annually among children aged <5 years worldwide despite the global expansion of rotavirus vaccination [1]. Rotaviruses are non-enveloped viruses, with three capsid layers encompassing 11 double-stranded RNA segments, which encode six structural (VP1-VP4, VP6, and VP7) and six nonstructural (NSP1-NSP6) proteins [2]. Based on the antigenicity of the major capsid

Objectives

The aim of this study was to describe the molecular epidemiology of RVA strains associated with neonatal outbreaks in Seoul during 2017-2020.

Sample collections

During 2017-2020, 1124 specimens (30-248 samples per outbreak) from 15 rotavirus outbreaks were submitted to the Seoul Metropolitan Government Research Institute of Public Health and Environment. A rotavirus outbreak was defined as more than two patients with symptoms of rotavirus gastroenteritis (diarrhea, vomiting, and fever) or two or more laboratory-confirmed cases within a short time at the same facility. After the detection of the first case of rotavirus, all neonates (and their mothers)

Results

From 2017 to 2020, 15 rotavirus outbreaks were reported in Seoul: 7 in 2017, 3 in 2018, 4 in 2019, and 1 in 2020 (Table 1). All of these outbreaks occurred in neonate-associated facilities (six in hospital neonatal wards and nine from postpartum care center). A total of 1124 specimens (814 from human and 310 from environment) were collected from outbreaks. Eighty-nine (10.9%) clinical samples were identified as positive by ELISA. All laboratory-positive patients were newborn infants except for

Discussion

In this study, we analyzed the genetic diversity of RVA strains isolated from neonatal outbreaks in Seoul. From 2017 to 2020, 15 RVA outbreaks occurred, comprising only two genotypes, G4P[6] and G8P[6].

G4P[6], the most common genotype among neonates in Korea [10,11], was predominantly observed until September 2018. Based on phylogenetic analysis, the G4P[6] strains in this study clustered with Korean epidemic strains. However, strains with a novel genotype, G8P[6], emerged in November 2018,

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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