Publications by authors named "Shoko Okitsu"
Article Synopsis
- A study analyzed 1,625 stool samples from children with diarrhea in Japan over four years (2018-2022) to detect human astroviruses (HAstVs) and other diarrheal viruses, finding HAstV in 8.6% of samples.
- The prevalence of HAstVs varied by year, with a notable increase to 20.1% in 2021-2022, and a significant infection rate was observed in children aged 1-3 years.
- The study identified multiple HAstV genotypes, including outbreaks of HAstV1 and MLB2 during the COVID-19 pandemic, and noted for the first time a mixed infection of HAstV1 and MLB1.
Article Synopsis
- Viral enteric infections, caused by norovirus, rotavirus A, and human adenovirus, significantly impact the gastrointestinal system, highlighting the need for rapid diagnostic tools like the immunochromatographic (IC) test.
- The IP-Triple I IC test kit was evaluated against known positive stool specimens and showed 100% specificity for detecting NoV, RVA, and HAdV, with varying sensitivity levels of 86.7% for RVA, 70.6% for NoV, and 76.2% for HAdV.
- The findings confirm that the IP-Triple I IC test kit is effective for quick detection of multiple viral genotypes in stool samples, proving valuable for timely diagnosis during outbreaks.
Article Synopsis
- Rotavirus A (RVA) is the leading cause of gastroenteritis in kids under five, with unique bat-like strains identified in Northern Thailand in 2005 and 2019.* -
- Genome sequencing and analysis showed that these strains have genetic similarities to bat RVA strains, indicating they may originate from bats but infect humans.* -
- The study highlights the importance of monitoring RVA in both humans and animals to understand their evolution and the potential for transmission between species.*
Article Synopsis
- Sapovirus (SaV) infections are on the rise globally, with a notable increase in Japan from 2010 to 2022, mainly due to the GI.1 genotype.
- The study analyzed 15 SaV GI.1 outbreak strains using next-generation sequencing and found distinct clustering in lineages and specific amino acid substitutions in their genomes.
- Key mutations associated with the pathogenicity and spread of SaV were identified in strains responsible for the largest outbreak in Japan (2021-2022), enriching the understanding of SaV's genetic makeup.
The FilmArray® Gastrointestinal (GI) Panel is a modern, sensitive, and comprehensive stool testing technique for identifying common gastrointestinal pathogens, including viruses, bacteria, and parasites. Its increasing demand is due to ease of operation and automation. Pathogens, particularly viruses, undergo constant genetic evolution.
View Article and Find Full Text PDFHuman adenovirus (HAdV) is one of the causative viruses of acute gastroenteritis (AGE) in children worldwide. Species F is known to be enteric adenovirus (genotypes 40 and 41) detected in stool samples. In Japan, we conducted an epidemiological study and molecular characterization of HAdV before and after the COVID-19 pandemic from 2017 to 2023.
View Article and Find Full Text PDFNorovirus (NoV) genogroup II, polymerase type P31, capsid genotype 4, Sydney_2012 variant (GII.P31/GII.4_Sydney_2012) has been circulating at high levels for over a decade, raising the question of whether this strain is undergoing molecular alterations without demonstrating a substantial phylogenetic difference.
View Article and Find Full Text PDFBackground: Acute gastroenteritis is one of the major causes of morbidity and mortality in young children worldwide. Among these, rotavirus, norovirus, and adenovirus have been reported as the primary viral pathogens associated with the disease. Rapid diagnosis of viral pathogens is crucial when diarrhea outbreaks occur to ensure the timely administration of appropriate treatment and control measures.
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- Human norovirus is a leading cause of acute gastroenteritis in all age groups, and this study focused on genetic variations of norovirus GI strains in hospitalized children in Chiang Mai, Thailand, from 2015 to 2021.
- A total of 2829 stool samples were analyzed, revealing that only 12 (0.4%) were positive for norovirus GI, with 58.3% of these identified as recombinant strains.
- The study found significant genetic diversity among the strains, indicating a complex landscape of both recombinant and non-recombinant norovirus GI strains contributing to gastroenteritis in the region. *
Article Synopsis
- Wastewater-based epidemiology (WBE) proved crucial during the COVID-19 pandemic as patients avoided clinics, allowing for ongoing tracking of enteric viruses in communities.
- A study was conducted analyzing raw sewage from Japan's Tohoku and Kansai regions from 2019 to 2022, focusing on major acute gastroenteritis (AGE) viruses using RT-PCR and sequence analysis.
- Findings revealed high prevalence of rotavirus A and astrovirus, with no decline in enteric viruses during the pandemic, while some strains, like norovirus GII.2, emerged and spread across the regions.
Article Synopsis
- Sapoviruses, like noroviruses, cause diarrhea in infants and the elderly and have been hard to study in the lab due to their difficulty in being replicated.
- Recent research shows that human sapovirus (HuSaV) can be replicated in vitro using human intestinal epithelial cells derived from tissue or cancer cell lines.
- The study found that multiple genotypes of HuSaV can infect human-induced pluripotent stem cell-derived IECs and can help researchers explore inactivation methods and vaccine responses under more realistic conditions.
Article Synopsis
- - Noroviruses (NoVs) cause significant outbreaks of acute gastroenteritis globally, and recent research indicates the emergence of new recombinant strains in various countries, including Japan.
- - A study analyzed 1,175 stool samples from Japanese infants and children over three years, finding 355 cases positive for NoV, with a predominance of GII genotypes, especially GII.4.
- - The research identified multiple genotypes and recombinant strains, highlighting a decrease in NoV infections among children during and after the COVID-19 pandemic, emphasizing the need for ongoing surveillance.
An increasing trend of sapovirus (SaV) infections in Japanese children during 2009-2019, particularly after the introduction of the voluntary rotavirus (RV)-vaccination program has been observed. Herein, we investigated the epidemiological situation of SaV infections from 2019 to 2022 when people adopted a precautionary lifestyle due to the emergence of the COVID-19 pandemic, and RV vaccines had been implemented as routine vaccines. Stool samples were collected from children who attended outpatient clinics with acute gastroenteritis and analyzed by reverse transcriptase-polymerase chain reaction to determine viral etiology.
View Article and Find Full Text PDFAfter rotavirus was discovered in 1973, it became the leading pathogen in causing acute gastroenteritis in humans worldwide. In this study, we performed whole genome sequencing and genomic characterization of a DS-1-like G2P[4] group A rotavirus in feces of a Japanese child with acute gastroenteritis who was fully Rotarix® vaccinated. The genomic investigation determined a genomic constellation G2-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2 of this rotavirus strain.
View Article and Find Full Text PDFBackground: Human astrovirus (HAstV) infection is one of the leading causes of acute gastroenteritis in young children. The present study reports the outbreak of HAstV in children with acute gastroenteritis in Kyoto, Japan, during the COVID-19 pandemic, 2021.
Methods: A total of 61 stool samples were collected from children with acute gastroenteritis who visited a pediatric outpatient clinic in Maizuru city, Kyoto, Japan from July to October, 2021.
Article Synopsis
- A study conducted in Bangladesh assessed the prevalence and genetic diversity of norovirus infections in children under 5, analyzing 404 fecal samples over nearly four years.
- Norovirus was detected in 6.7% of samples, with the GII.4 Sydney-2012 strain being the most common, and co-infection with rotavirus was also observed.
- The rapid diagnostic method using an immunochromatography kit proved highly effective, showing 100% sensitivity and 99.3% specificity in detecting norovirus.
Many different enteric viruses can cause acute gastroenteritis in humans worldwide. While a single virus can indeed cause disease, multiple-virus infections are commonly reported. However, data regarding a comparison between single- and multiple-virus infections upon clinical manifestations of acute gastroenteritis are relatively limited.
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- Human astroviruses (HAstVs) are significant causes of acute gastroenteritis (AGE) in children, with MLB1 and HAstV1 being the most common genotypes identified in Japan from 2014 to 2021.
- Out of 2,841 stool samples collected, 4.6% tested positive for HAstVs, with MLB1 (45.4%) and HAstV1 (39.2%) dominating the infections, alongside lesser-known genotypes like MLB2 and VA2.
- This research sheds light on the epidemiology and genetic diversity of HAstVs in Japan, marking the first detection of the rare MLB3 genotype and highlighting the potential role of HAstVs beyond gastro
Article Synopsis
- * Raw sewage samples from Japan (2018-2022) showed a significant rise (10-20%) in AGE viruses such as rotavirus and norovirus during the pandemic, while some others saw small decreases.
- * The research highlighted the emergence and increase of multiple viral strains during this period, emphasizing the need to monitor sewage water for a better understanding of ongoing viral activity when clinical data may be lacking.
Unusual DS-1-like intergenogroup reassortant rotaviruses with a bovine-like G8 genotype (DS-1-like G8P [8] rotaviruses) have emerged and rapidly spread in several countries. In this study, the nucleotide sequences of seven human rotavirus G8P [8] strains in 2017 and 2019 in Japan were determined using viral metagenomics. Its genomic constellation (VP7-VP4-VP6-VP1-VP2-VP3-NSP1-NSP2-NSP3-NSP4-NSP5 genes) was defined as G8-P [8]-I2-R2-C2-M2-A2-N2-T2-E2-H2.
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- Rubella virus (RuV) infections during early pregnancy, particularly in the first trimester, can result in congenital rubella syndrome (CRS), although not all infections lead to this outcome, highlighting a gap in understanding the infection mechanisms.* -
- The study explores how hypoglycemia-related endoplasmic reticulum (ER) stress might influence vertical RuV infection, using human trophoblast cells subjected to low or high glucose conditions before infection.* -
- Results show that low-glucose-induced stress increased RuV infection and viral production in trophoblasts without significant cell death, indicating that early pregnancy low glucose levels may enhance susceptibility to RuV and contribute to CRS.*
Article Synopsis
- Rotavirus A (RVA) is a leading cause of severe gastroenteritis in children globally, and Japan introduced two rotavirus vaccines in 2011 and 2012, which became part of their national program in 2020.
- A study analyzed stool samples from children with gastroenteritis in Japan from 2014 to 2020 to investigate the prevalence and genetic diversity of RVA during the voluntary vaccination period.
- Findings showed a decrease in RVA detection rates over time, coinciding with increased vaccination rates, and a yearly change in the distribution of RVA genotypes, highlighting the evolving nature of rotavirus strains.
Article Synopsis
- Human norovirus (HuNoV) is a leading cause of acute gastroenteritis globally, and researchers have been using norovirus-like particles (VLPs) to study how the virus interacts with host cells.
- This study developed a system using NanoLuc luciferase complementation to quantitatively detect the entry of HuNoV VLPs into live cells, focusing on their interaction with Vero cells and finding that Caco-2 cells were the most susceptible.
- The VLP entry was stable under acidic conditions above pH 3 but significantly reduced when exposed to heat above 75°C for more than 2 minutes, confirming previous findings about VLP stability and cell attachment.