• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.20 no.2
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• pp.130-133
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• 2017

Noroviruses have been recognized as the leading cause of epidemic and sporadic gastroenteritis since the advent of molecular diagnostic technique. They have been documented in 5-31% of pediatric patients hospitalized with gastroenteritis. Although norovirus gastroenteritis is typically mild and self-limited, it causes severe, but sometimes fatal, conditions in the vulnerable population such as immunocompromised patients, young children, and the elderly. Bowel perforation due to norovirus infection is rare. We report a case of small bowel perforation with norovirus gastroenteritis in the infant with Down syndrome during the hospitalization with pneumonia. Severe dehydration may cause bowel ischemia and could have triggered bowel perforation in this case. Physicians should be alert to the potential surgical complications followed by severe acute diarrhea, especially in high risk groups.

• Korean Journal of Veterinary Service
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• v.46 no.3
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• pp.235-241
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• 2023

Noroviruses are a major cause of gastroenteritis in humans and animals worldwide. In 2021, canine norovirus (CNoV) infection was detected at an animal clinic in Gwangju area, South Korea. A semi-nested polymerase chain reaction was developed to amplify a 478 bp fragment of the RdRp gene of CNoV. The phylogenetic analysis of this fragment confirmed the strain to be genogroup IV.2 (Dog/GIV.2/gw/s377/2021/KOR), which exhibited the highest similarity to the feline NoV strain GIV.2/CU081210E/USA/2010 (accession no. NC_045762) with 95.1% nucleotide (nt) identity and 98.7% amino acid (aa) identity. These research findings indicate that the detected norovirus in dogs is genetically similar to a feline-origin norovirus, suggesting easy cross-species transmission among animals.

• Journal of Life Science
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• v.26 no.8
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• pp.911-920
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• 2016

Norovirus is the most common causative agent of acute gastroenteritis. This study was carried out to investigate molecular epidemiology of norovirus infections from outbreaks in Busan from 2012 to 2015. Total of 581 stool specimens were collected from diarrhea patients in outbreaks in Busan, 71 samples were resulted in positive to norovirus. The data were analyzed according to seasonality, patient, age and gender. Noroviruses were detected most frequently during the winter season from November (25.4%) to February (28.2%). The age group from teens was the most susceptible to norovirus infections. To obtain the molecular genetic information of norovirus, we performed sequencing analyses of the strains detected. Norovirus genotypes have been reported to show high genetic diversity. Four kinds of GI genotypes (GI-1, GI-2, GI-3, GI-5) and five kinds of GII genotypes (GII-1, GII-4, GII-5, GII-6, GII-17) were indentified in outbreaks in Busan. Other previous studies have shown that GII-4 is the most predominant circulating in Korea and worldwide. The most prevalent norovirus genotypes of each year were GII-6 in 2012, GII-6 in 2013, GII-4 in 2014 and GII-6 in 2015. Except for 2014, GII-6 genotype was the most prevalent and predominant in Busan. We described the epidemiological analysis of the noroviruses in outbreaks in Busan. The result of this study will contribute to update the epidemiological data and improve hygiene and public health via sustainable surveillance.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.123-131
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• 2017

Norovirus causes frequent epidemic viral gastroenteritis in Korea. The team for the control of noroviral foodborne outbreaks (NOROTECL) executed a project to trace the cause of norovirus contamination in agricultural products and environmental samples to reduce norovirus outbreaks in Korea. Between January and November in 2015, the contaminations by norovirus and indicator microorganisms such as coliforms, Escherichia coil and male specific coliphage (MSC) were examined in 80 agricultural products, 80 soil samples, 78 human feces samples, 3 animal feces samples, 80 agricultural water samples and 80 river water samples. Semi-nested PCR and DNA sequencing revealed 18 genogroup I and 3 genogroup II noroviruses in a total of 18 samples. These noroviruses were validated by real-time (RT)-PCR analysis. For indicator microorganisms, coliform and E. coli were respectively detected in agricultural products (68, 1%), soils (88, 7%), human feces (44, 12.8%), animal feces (67, 67%), agricultural waters (74, 30%) and river waters (96, 51%). The MSC results revealed 14 positive samples.

• Journal of Microbiology and Biotechnology
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• v.20 no.2
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• pp.229-237
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• 2010

Recently, many cases related to viral gastroenteritis outbreaks have been reported all over the world. Noroviruses are found to be leading as the major cause of outbreaks of acute gastroenteritis. Patients with acute gastroenteritis are normally found to be positive with norovirus when the stools and vomit are analyzed. This paper reviews various activities and previous reports that describe norovirus contamination in various food matrixes and the relationship between food handlers. Lately, a numbers of norovirus outbreaks have been reported that are involved with fresh produce (such as vegetables, fruits), shellfish, and prepared food. Food produce processed by infected food handlers may therefore become easily contaminated. In addition, foods that required much handling and had been eaten without heat treatment gave the high risk for getting foodborne illnesses. The standard method for detection of norovirus has already been available for stool samples. However, only a few methods for detection of norovirus in food samples have been developed until now.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.102-108
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• 2012

Fecal specimens from acute gastroenteritis in Seoul from 2003 to 2007 were collected and then tested for the presence of Norovirus by RT-PCR. Among a total of 4,685 samples investigated, 383 samples (8.2%) were positive. The analysis of outbreaks related norovirus contamination occurred from 2003 to 2007 in Seoul revealed 57 cases happened during investigated period. Seasonal prevalence showed winter season predominant characteristics of pattern of epidemics by long term investigation for norovirus infections. The incidence of norovirus infection in the case of acute gastroenteritis by catering food in school were 32%, by food in general restaurant were 29%. This epidemiological investigation in Seoul was strongly needed for control and prevention of outbreaks related with norovirus by forecasting disease epidemics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.898-903
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• 2015

Noroviruses (NoV) are known to cause acute epidemic gastroenteritis worldwide. Outbreak strains are predominantly genogroup I (GI) and genogroup II (GII) in oysters Crassostrea gigas. We investigated the changes in concentration of male specific coliphage (MSC) and NoV under heat treatment of the naturally contaminated oyster, Crassostrea gigas. After heat treatment for 5 min in $85^{\circ}C$, no viable MSC was detected. The concentrations of GI and GII NoV decreased by 1.65 log and 2.25 log, respectively, following heat treatment for 5 min at $100^{\circ}C$. Moreover, both GI and GII NoV were completely deactivated by heat treatment for 10 min at $100^{\circ}C$. Therefore, in order to reduce the risk of norovirus infection from contaminated oysters, immersion in boiling water for at least 10 min is recommended.

• Proceedings of the Microbiological Society of Korea Conference
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• 2008.05a
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• pp.171-171
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• 2008

We monitored the occurrence of human enteric viruses in urban rivers by cell culture-PCR and RT-nested PCR. Water samples were collected monthly or semimonthly between May 2002 and March 2003 in four urban tributaries. Enteric viruses were detected by RT-nested PCR and cell culture-PCR based on a combination of Buffalo Green monkey kidney (BGMK) and A549 cell lines, followed by phylogenetic analysis of amplicons. By RT-nested PCR analysis, 45 (77.6%), 32 (55.2%), 32 (55.2%), 26 (44.8%), 12 (20.7%), 2 (3.4%), 4 (6.9%), and 4 (6.9%) of 58 samples showed positive results with adenoviruses, enteroviruses, noroviruses (NV) genogroup I (GI) and II (GII), reoviruses, hepatitis A viruses, rotaviruses and sapoviruses, respectively. Adenoviruses were most often detected and only eight (13.8%) samples were negative for adenoviruses and positive for other enteric viruses in the studied sites. Thirty-one (77.5%) of the 40 samples were positive for infectious adenoviruses and/or enteroviruses based on cell culture-PCR, and the frequency of positive samples grown on A549 and BGMK (65.0%) was higher than that grown on BGMK alone (47.5%). The occurrence of each enteric virus, except reoviruses and hepatitis A viruses was not statistically correlated with the water temperature and levels of fecal coliforms according to Binary logistic regression model. By sequence analysis, most strains of adenoviruses and enteroviruses detected in this study are similar to the causative agent of viral diseases in Korea and most NV GI- and GII-grouped strains were closely related to the reference strains from China and Japan, and GII/4-related strains had similar sequences to strains recognized as a worldwide epidemic outbreak. Our results suggested that monitoring human enteric viruses is necessary to improve microbial quality and cell culture-PCR using the combination of A549 and BGMK cells and the adenovirus detection by PCR could be useful for monitoring viral contamination in the aquatic environment.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.556-562
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• 2014

The occurrence of human norovirus (NoV) genogroup I (GI) and genogroup II (GII) strains was investigated in Korea. Between 2007 and 2010, 265 samples were collected from 89 Korean water source locations. NoV GI was detected in 4.5% and NoV GII in 1.5%. Samples collected in winter had the highest occurrence; 9.4% for NoV GI and 6.3% for NoV GII. NoV GI detection was highest in groundwater, with the next highest in river water and the lowest in lake water (5.9%, 5.4%, and 1.6%, respectively), and NoV GII was found only in river water. When three representative Korean basin systems (Han (H)-, Geum/Seom (G/S)-, and Nakdong (N)-river basins) were compared, both NoV genogroups were high in the G/S-, but absent in the H- river basin. The most prevalent genotypes within the GI and GII groups were GI.5 and GII.4, respectively. The NoVs found in surface water were identical to those found in patients and those found in groundwater. The NoVs appeared to be transmitted from the patient to the surface water, and then to the groundwater, suggesting a fecal-oral route of transmission. This is the first nationwide surveillance of NoV in major Korean water sources.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.126-134
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• 2022

Norovirus (NoV) is an important pathogen causing acute gastroenteritis worldwide. The purpose of the present study was the molecular characterization of NoV. A total of 408 stool specimens collected from hospitalized children associated with acute gastroenteritis in Chiang Rai, Thailand, 2015-2017 were investigated for the presence of NoVs by RT-PCR. NoV GII was detected in 32 samples (7.8%). Five distinct genotypes were identified, including GII.4 (13/32, 40.6%), GII.3 (11/32, 34.3%), GII.17 (4/32, 12.5%), GII.2 (2/32, 6.3%), and GII.14 (2/32, 6.3%). NoV infection occurred mostly in young children under 3 years of age (31/32, 96.9%) and showed the main peak in summer months from March to April (18/32, 56.3%). Phylogenetic analysis revealed that all 13 GII.4 strains clustered with GII.4 Sydney 2012 variant. Representative GII.3 strains were analyzed as a recombinant GII.3P[12] strain. Several amino acid differences were found in the antigenic epitopes and antibody binding sites of the VP1 capsid of the GII.3P[12]. Homology modeling of the P domain of the GII.3P[12] strain demonstrated that 10/13 amino acid differences were predicted to be located on the surface-exposed area of the capsid structure. These amino acid changes might affect the infectivity and the antigenicity of the recombinant GII.3P[12]. The prevalence of GII.4 Sydney 2012 and recombinant GII.3P[12] strains indicates the genetic diversity of circulating NoVs in Thailand, emphazing the importance of continuous surveillance to mornitor newly emerging NoV strains in the future.