• The Journal of the Korean Society for Microbiology
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• v.34 no.5
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• pp.453-459
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• 1999

Astrovirus is frequently associated with diarrhea in children. It can not be readily isolated by cell culture, and an electronmicroscope is usually used for detection of this agent. Recently in 1995 a combined method of reverse transcription-polymerase chain reaction (RT-PCR) was designed for easier detection of astrovirus, which is based on the conserved sequence in 3'-end of genomes of the 7 known serotypes of human astrovirus. As of yet there has not been any report of astrovirus data in Korea using the RT-PCR methods. The purpose of this study was to detect astrovirus incidence, severity of symptoms, seasonal variation and co infection rate with rotavirus in Korean children inpatients with diarrhea. Fecal specimens from 61 young children hospitalized with gasteroenteritis Korea from Jan. 1996 through Mar. 1997. They were examined for astroviurs infection by RT-PCR method. Results are as follows:1. Astrovirus was detected at 9.8% (6/61) from fecal specimens of children with severe diarrhea by EIA using monoclonal antibody coated plates. 2. Astorvirus was detected at 29.5% (18/61) from fecal specimens of children with severe diarrhea by RT-PCR. 3. The age of the 18 children affected by astrovirus ranged from 2 monthes to 7 years with mean of 3.0 years. 4. Mean hospital stay of the 18 children was 6.1 days. 5. Five (27.8%) astrovirus RT-PCR positive strains were confirmed in November and in December, respectively out of 18 specimens in total. 6. Astrovirus coinfection with rotavirus type G1 was confirmed in 15/16 specimens (93.8%), and with type G2 was in 1/16 specimens (6.3%).

• Journal of Life Science
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• v.26 no.9
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• pp.999-1006
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• 2016

This paper studies an infection of norovirus and astrovirus in outbreaks in Korea. In March 2016, gastroenteritis outbreaks occurred in Busan. 522 students of three departments at university D had meeting at a restaurant near the university. Some of them had symptom such as diarrhea, vomiting. Epidemiological, laboratory and environmental investigations were performed to identify the agents of the outbreaks. Fecal specimens were collected from 35 students and 7 food handlers to identify causative viral agents. Norovirus genogroup GI and GII were detected from diarrhea patients. Astrovirus was also detected from some of them. In particular, these outbreaks were the first occurrence associated with astrovirus in Busan. Total of 42 samples were collected, and 24 samples resulted in positive to norovirus (16 cases) and astrovirus (8 cases). To identify the molecular genetic information of norovirus, we carried out sequences analysis of the detected strains. Norovirus genotypes were classified into GI.3, GI.4, GII.4, GII.13, GII.17 and GII.21. Astrovirus genotypes were seven astrovirus type 5 and one astrovirus type 2. We performed environmental investigation about water at the kitchen, but norovirus and astrovirus were not detected. The statistical analysis was conducted to evaluate the association between illness and risk factors. The results of this study may contribute to accumulate more the epidemiological data and develop the public health and hygiene.

• Pediatric Infection and Vaccine
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• v.19 no.1
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• pp.28-36
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• 2012

Purpose : This study was conducted to evaluate epidemiological data of the viral pathogens obtained from stool exams and provide information on the regional prevalence of infectious diarrheal disease west in Gyeonggi Province, Korea. Methods : We enrolled a cohort of children <10 years of age admitted for treatment of acute diarrhea at Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea. In total, 310 fecal specimens, documented to be free of common bacterial pathogens, were collected from pediatric patients during a 12-month period from January to December 2009 and were tested for the presence of rotavirus, parechovirus, adenovirus, astrovirus, enterovirus, and norovirus using polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR) assay. Results : The most common virus was parechovirus (16%), followed by adenovirus (15%), astrovirus (14%), rotavirus (13%), and enterovirus (5%). Interestingly, only one of the specimens was positive for norovirus. Single infection cases were detected in 173 (55.8%) of the 310 children, whereas mixed viral infections were detected in 10 (3.2%) of the same children. Viral gastroenteritis generally showed a double peak of incidence. Parechovirus, rotavirus, and adenovirus shared a similar pattern of peak incidence with overall viruses; however, astrovirus infections occurred more frequently in the spring. Eighty-five percent of the confirmed viral gastroenteritis cases developed in under 24 months. Conclusion : The results support the importance of parechovirus, adenovirus, astrovirus, and enterovirus as causative agents of diarrhea in children, which may be underestimated by current routine diagnostic testing.

• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.210-217
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• 2018

A one-step multiplex reverse transcription PCR (RT-PCR) method comprising six primer sets (for the detection of norovirus GI and GII, hepatitis A virus, rotavirus, and astrovirus) was developed to simultaneously detect four kinds of pathogenic viruses. The size of the PCR products for norovirus GI and GII, hepatitis A virus (VP3/VP1 and P2A regions), rotavirus, and astrovirus were 330, 164, 244, 198, 629, and 449 bp, respectively. The RT-PCR with the six primer sets showed specificity for the pathogenic viruses. The detection limit of the developed multiplex RT-PCR, as evaluated using serially diluted viral RNAs, was comparable to that of one-step single RT-PCR. Moreover, this multiplex RT-PCR was evaluated using food samples such as water, oysters, lettuce, and vegetable product. These food samples were artificially spiked with the four kinds of viruses in diverse combinations, and the spiked viruses in all food samples were detected successfully.

• Clinical and Experimental Pediatrics
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• v.55 no.3
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• pp.77-82
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• 2012

Human astrovirus (HAstV) is a major cause of acute diarrhea among children, resulting in outbreaks of diarrhea and occasionally hospitalization. Improved surveillance and application of sensitive molecular diagnostics have further defined the impact of HAstV infections in children. These studies have shown that HAstV infections are clinically milder (diarrhea, vomiting, fever) than infections with other enteric agents. Among the 8 serotypes of HAstV identified, serotype 1 is the predominant strain worldwide. In addition to serotype 1, the detection rate of HAstV types 2 to 8 has increased by using newly developed assays. HAstV is less common compared with other major gastroenteritis viruses, including norovirus and rotavirus; however, it is a potentially important viral etiological agent with a significant role in acute gastroenteritis. A better understanding of the molecular epidemiology and characteristics of HAstV strains may be valuable to develop specific prevention strategies.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.173-182
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• 2020

Human Astrovirus (HuAstV), known as a waterborne virus, is a group IV positive-sense single-stranded RNA that belongs to Astroviridae. The first outbreak of HuAstV was reported in England in 1975. HuAstV can exist not only among clinical patients but also in various water environments, such as water for agriculture and vegetables. For diagnosis of HuAstV from water samples, a polymerase chain reaction (PCR) system has been developed. However, the PCR-based diagnostic method has problems in field application, such as reaction time, sensitivity and specificity. For this reason, in this study we developed the loop-mediated isothermal amplification assay (LAMP) system, aimed specifically at HuAstV. Three prepared LAMP primer sets were tested by specificity, non-specificity and sensitivity; one LAMP primer set was selected with optimum reaction temperature. The developed LAMP primer set reaction conditions were confirmed at 62℃, and detection sensitivity was 1 fg/μL. In addition, restriction enzyme HaeIII (GG/CC) was introduced to confirm that the LAMP reaction was positive. As a result, selected LAMP primer set was 100 - 1000 times more specific, rapid, and sensitive than conventional-nested PCR methods. For verification of the developed LAMP assay, twenty samples of cDNA from groundwater samples were tested. We expect that the developed LAMP assay will be used to diagnose HuAstV from various samples.

• Biomedical Science Letters
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• v.27 no.4
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• pp.255-263
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• 2021

Human Astrovirus (HuAstV) is an important gastrointestinal pathogen that is frequently reported worldwide. Monitoring of contaminated groundwater has been suggested since HuAstV is transmitted through the fecal-oral route. This study developed a test method based on conventional reverse transcription (RT)-nested polymerase chain reaction (PCR) that involves SL^® non-specific reaction inhibitor for unknown non-specific amplification taking place in the groundwater environment. An optimal method for detecting HuAstV in groundwater sample through analysis and comparison against conventionally reported method was also suggested. The developed method enabled the production of nested PCR amplicon of 630 nt, which is a sufficient length for similarity analysis based on sequencing and genotyping. Amplicons suspected to be HuAstV were amplified in two out of the twenty groundwater samples collected in Korea, presenting 99.77% and 99.73% similarity against HuAstV 1 strain lhar/2011/kor (JN887820.1) in sequencing, respectively. These amplicons were identified as HuAstV 1.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.2
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• pp.143-152
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• 2004

Purpose: The purpose of this study is to detect viral coproantigens in children who were hospitalized with acute diarrhea and to compare its association with clinical symptoms. Methods: Seventy-four stool samples were collected from children admitted to Ewha Mokdong Hospital from March 1996 to December 1999. The samples were frozen and analyzed for rotavirus, adenovirus, enterovirus, astrovirus, and calicivirus by enzyme immunoassay (EIA) with monoclonal antibody. 53 stool samples were collected from patients with diarrhea (diarrheal group) and 21 stool samples from patients hospitalized for reasons other than diarrhea (control group). Clinical features and laboratory findings were reviewed in both groups. Results: Among 74 stool samples, virus antigens were detected in 60 samples. Of the 60 virus-positive stool samples, 47 enterovirus, 26 rotavirus, 16 adenovirus, 11 astrovirus, and 11 calicivirus antigens were detected by EIA. Of the 60 virus-positive stool samples, 28 samples have one viral antigen, 30 samples have 2 or more viral antigens, and 2 samples showed a simultaneous infection of Salmonella group B and enterovirus. There was no relationship between the detected virus and clinical features. Conclusion: In this study, viral coproantigen and clinical symptoms were not associated. In the future, further larger scale studies are necessary.

• Clinical and Experimental Pediatrics
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• v.59 no.3
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• pp.120-125
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• 2016

Purpose: Viral gastroenteritis among children is mainly caused by rotavirus, norovirus, astrovirus, or adenovirus strains. However, changing socioeconomic conditions and a rotavirus vaccination program may be affecting the prevalence of these viral infections. Therefore, we aimed to elucidate the season-specific trends in viral infections for facilitating prophylaxis and surveillance in our region. Methods: We evaluated 345 pediatric patients (203 males, 142 females; age, 1 month to 16 years) who visited the CHA Bundang Medical Center because of gastroenteric symptoms between June 2014 and May 2015. The specimens were simultaneously tested for norovirus, rotavirus, astrovirus, and adenovirus via multiplex reverse transcription polymerase chain reaction. Clinical characteristics of patients were analyzed retrospectively. Results: The most common virus was norovirus, followed by rotavirus, adenovirus, and astrovirus. Of all viral infections, 45.2% occurred mainly between 6 and 24 months of age; in particular, norovirus infection mostly occurred in all age groups except those below 6 months of age, when rotavirus was most prevalent. In addition, seasonal variation was observed, such as norovirus infection from December to February, rotavirus infection from February to April, and adenovirus infection from July to October. Conclusion: Our results showed that the most common cause of acute pediatric viral gastroenteritis had changed from rotavirus to norovirus in our patients, because of effective rotaviral vaccination. We recommend the management of food and personal hygiene in accordance with age or seasons as well as active vaccination for preventing viral gastroenteritis.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.2
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• pp.139-146
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• 2006

Purpose: Human astrovirus (HAstV) is known to be an important etiologic agent of acute gastroenteritis in infants worldwide. However, the prevalence of HAstV infection varies according to geographic region and patient age. The purpose of our study was to investigate the incidence of HAstV infection among hospitalized children at a tertiary hospital in Seoul. Methods: Fecal samples were collected from hospitalized children up to five years of age with acute gastroenteritis. A total of 812 fecal samples were collected from hospitalized children with acute gastroenteritis between February 2004 and January 2005. Fecal specimens were screened for rotavirus, enteric adenovirus and norovirus by enzyme immunoassay (EIA) or reverse transcriptase polymerase chain reaction (RT-PCR). HAstV positive samples were characterized by RT-PCR. Results: Rotavirus was detected in 16.9% (138/812), norovirus in 11.6% (94/812), and adenovirus in 4.0% (33/812) of the study population. HAstV was detected in 4.0% (33/812) samples by RT-PCR. The age distribution of HAstV positive patients was as follows: <12 month old, 82.0% (27/33); 1~2 years old, 6.0% (2/33); 2~5 years old, 12.0% (4/33). The seasonal distribution of HAstV positive samples was as follows; April (3), May (5), June (4), August (12), September (4), October (2), November (2), and December (1). The peak rate of HAstV infection was observed during the summer season, 2004. A mixed infection of viral agents was confirmed in 2.7% (22 /812) of the study population, most commonly with rotavirus and norovirus, and with rotavirus and HAstV. Genotype 1 was the predominant type (91%, 20/22) and genotype 8 was detected in two cases. Conclusion: The prevalence of HAstV infection was 4.0% in hospitalized children with acute gastroenteritis, and was especially high in infants. HAstV can be considered as an important etiologic agent of gastroenteritis in children.