Gastroenteritis ; etiology ; virology ; Human bocavirus ; isolation & purification ; Humans ; Parvoviridae Infections ; diagnosis ; Respiratory Tract Diseases ; etiology ; virology

OBJECTIVETo study the clinical manifestations for norovirus gastroenteritis in infants and young children.

METHODSStool specimens were collected from infants and children with acute diarrhea who visited the affiliated Children's Hospital to Capital Institute of Pediatrics from January 2002 to December 2006. Enzyme-linked immunosorbent assay (ELISA) was used to detect human norovirus antigen in stool specimens and polyacrylamide gel electrophoresis (PAGE) was performed to detect rotavirus genome.

RESULTSOut of the 318 specimens under testing, 79 showed positive for norovirus antigen, with a positive rate of 24.8% (79/318). Among those positive specimens, 48(48/79, 60.8%) were detected in October to December, suggesting the seasonal preference of the virus. Most of the positive specimens (91.2%) were from those under 2 years of age. Rotavirus genome were detected from 16 out of 79 norovirus positive specimens (16/79, 20.3%), indicating those patients were co-infected by these two viruses. There was significant difference found in the severity of fever but not in the frequencies of diarrhea between rotavirus and norovirus co-infection group and noroviral infection group. Fourteen out of 79 norovirus positive patients were admitted to hospitals under the diagnosis other than gastroenteritis but started to develop symptoms of diarrhea between 1 to 11 days after hospitalization.

CONCLUSIONNorovirus seemed one of the most important pathogens for acute diarrhea among infants and young children and could cause nosocomial infectious gastroenteritis.

Caliciviridae Infections ; diagnosis ; virology ; Child ; Child, Preschool ; Electrophoresis, Polyacrylamide Gel ; Enzyme-Linked Immunosorbent Assay ; Female ; Gastroenteritis ; diagnosis ; virology ; Genome, Viral ; genetics ; Humans ; Infant ; Male ; Norovirus ; classification ; genetics ; pathogenicity

The object of this study is to develop a duplex fluorescent quantitative one-step RT-PCR assay for detection and quantitation of GI and GII norovirus. The specific primers, Taqman probes, optimized reaction solution and condition were used to develop the duplex fluorescent quantitative one-step RT-PCR assay. The sensitivity, specificity and reproducibility of the assay were evaluated. The assay was evaluated by testing the 100 specimen samples and compared with the reference assay conventional RT-PCR. The assay possessed high specificity for norovirus detection without any evident cross-reaction with enteric adenovirus, rotavirus or astrovirus. The detection limit of the real-time RT-PCR assay, for GI and GII norovirus was up to 10(3) copy/microL respectively. Compared with the conventional RT-PCR assay, the assay in this study had higher sensitivity with higher detection rate of norovirus in stool specimens. The duplex fluorescent quantitative one-step RT-PCR assay provides rapid, sensitive and reliable detection of GI and GII norovirus, and could be used as a laboratory diagnosis of norovirus in acute gastroenteritis patients.
DNA Primers ; genetics ; Feces ; virology ; Gastroenteritis ; diagnosis ; virology ; Genotype ; Humans ; Norovirus ; classification ; genetics ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; instrumentation ; methods

Noroviruses are the leading cause of epidemic gastroenteritis, including foodborne outbreak, in Korea. The prevalence of human noroviruses was studied in diarrheal stool samples of patients with acute gastroenteritis by conventional duplex reverse transcription (RT)-PCR. Diarrheal stool samples were collected from 1,685 patients from the local hospitals in Seoul. The prevalence of the noroviruses was 22.8% (222/972 patients) in 2012 and 11.2% (80/713 patients) in 2013, with a total of 17.9% (302/1,685 patients). Genotyping was performed on 302 norovirus-positive stool samples to reveal 5.6% prevalence of genogroup I (GI) (17/302) and 94.4% prevalence of genogroup II (GII) (285/302). The patients with norovirus-associated acute gastroenteritis mostly showed prevalence of GII norovirus, especially GII.4 (64.6%; 195/302).
Acute Disease ; Feces/virology ; Gastroenteritis/*diagnosis/epidemiology/virology ; Genotype ; Humans ; Norovirus/*genetics/isolation & purification ; Prevalence ; RNA, Viral/genetics/metabolism ; Real-Time Polymerase Chain Reaction

Because of limited viral replication and lack of cytopathic effect in cell culture, a new PCR-based rapid seroneutralization assay for detection of GII.4 norovirus neutralized antibodies was developed with serum samples from acute-phase patients, convalescent-phase patients and healthy controls. According to this study, neutralizing antibodies were detected in 100% of convalescent-phase sera, and in 2.5% of healthy controls sera. However, all of the acute-phase serum samples could not neutralize virus efficiently. Compared to the results from ELISA (96.2% at sensitivity and 80% at specificity), the present in vitro neutralization assay is more specific and more sensitive.
Antibodies, Neutralizing ; immunology ; Base Sequence ; Caliciviridae Infections ; diagnosis ; virology ; Case-Control Studies ; Cell Line ; DNA Primers ; Enzyme-Linked Immunosorbent Assay ; Gastroenteritis ; diagnosis ; virology ; Humans ; Norovirus ; immunology ; isolation & purification ; Polymerase Chain Reaction ; methods ; Sensitivity and Specificity

BACKGROUND: Rotavirus is the most common cause of childhood gastroenteritis during winter season. Rapid, accurate diagnosis is essential for preventing severe complications of rotaviral gastroenteritis. The sensitivity and specificity of five detection test kits for rotavirus including latex agglutination (LAT), enzyme immunoassay (EIA) and three immunochromatographic methods (ICG) were evaluated in this study. METHODS: A total of 95 stool samples collected from patients with acute gastroenteritis were studied. The test kits were as follows: LAT (Slidex latex, bioMerieux Vitek, France); three kinds of ICG (Dipstick ROTA, Eiken, Japan; SAS Rota Test, SA Scientific, Inc., USA; and ASAN Easy Test Rota strip, ASAN Pharmaceutical., Korea); and EIA (VIDAS Rotavirus, bioMerieux Vitek). The samples showing discordant results were reevaluated by reverse-transcription (RT) PCR and clinical manifestations. RESULTS: Of a total of 95 cases, 56 (58.9%) were positive and 39 (41.1%) were negative. Thirteen cases showed discordant results. Sensitivity and specificity were, respectively, 85.7% and 100% for LAT, 100% and 95% for both of Dipstick ROTA and SAS Rota, 86.7% and 87.5% for ASAN Rota strip and 98.1% and 97.3% for EIA. CONCLUSIONS: LAT was rapid and easy to perform and showed the lowest sensitivity among the five test kits. ICG showed a good agreement with EIA and RT-PCR. EIA was the best in respect of sensitivity and specificity, but difficulty in interpretations of equivocal results and time-consuming procedures were limitations. In conclusion, ICG, which is easy to perform at a low cost, may be an optimal method in place of LAT for the detection of rotavirus.
Antigens, Viral/*analysis ; Chromatography/*methods ; Enzyme-Linked Immunosorbent Assay/*methods ; Gastroenteritis/virology ; Humans ; Latex Fixation Tests/*methods ; Reagent Kits, Diagnostic ; Reverse Transcriptase Polymerase Chain Reaction ; Rotavirus/immunology/*isolation & purification ; Rotavirus Infections/*diagnosis ; Sensitivity and Specificity

INTRODUCTIONNorovirus gastrointestinal disease (GID) outbreaks occur frequently in closed settings, with high attack rates. On October 16, 2008, a norovirus GID outbreak occurred at a Singapore military camp. This study describes the epidemiological investigations conducted to determine the cause of outbreak and the efficacy of the public health measures implemented.

METHODSEpidemiologic investigations included a case-control study of exposure to different food items and an environmental exposure survey. Stool samplings of patients and food handlers for common pathogens, and microbiologic testing of food and water samples were performed. Inspection of dining facilities and health screening of all food-handlers were also conducted.

RESULTSA total of 156 GID cases were reported on October 15-31, 2008. 24 (15.4%) personnel were positive for norovirus. The predominant symptoms were diarrhoea (76.3%) and abdominal pain (69.2%). There was no clinical correlation between any food item and the affected personnel. Testing of food and water samples, dining facility inspections and health screening of food handlers showed satisfactory results. The environmental exposure survey indicated possible transmission due to environmental contamination by vomitus in common areas. Comprehensive environmental decontamination was performed with hypochlorite solution, and personal hygiene measures were enforced. The outbreak lasted 17 days, with a decline in cases post intervention.

CONCLUSIONTimely notification and prompt response can curtail disease transmission. Swift implementation of public health measures, such as emphasis on personal hygiene, isolation of affected cases and comprehensive disinfection of the environment, effectively stopped norovirus transmission and may be adapted for future GID outbreaks.

Acute Disease ; Adolescent ; Caliciviridae Infections ; diagnosis ; epidemiology ; Case-Control Studies ; Communicable Disease Control ; methods ; Diarrhea ; virology ; Disease Outbreaks ; statistics & numerical data ; Feces ; virology ; Food Handling ; Gastroenteritis ; epidemiology ; virology ; Humans ; Male ; Military Facilities ; Norovirus ; isolation & purification ; Singapore ; epidemiology ; Water Microbiology ; Young Adult

Rapid and accurate detection of norovirus is essential for the prevention and control of norovirus outbreaks. This study compared the effectiveness of a new immunochromatographic assay kit (SD BIOLINE Norovirus; Standard Diagnostics, Korea) and real-time reverse transcription-PCR (RT-PCR) for detecting norovirus in fecal specimens. Compared with real-time RT-PCR, the new assay had sensitivity, specificity, positive predictive value, and negative predictive value of 76.5% (52/68), 99.7% (342/343), 98.1% (52/53), and 95.5% (342/358), respectively. The sensitivity of the assay was 81.8% (18/22) for GII.3 and 75.7% (28/37) for GII.4. None of the 38 enteric virus-positive specimens (3 for astrovirus, 5 for enteric adenovirus, and 30 for rotavirus) tested positive in the cross-reactivity test performed by using this assay. The new immunochromatographic assay may be a useful screening tool for the rapid detection of norovirus in sporadic and outbreak cases; however, negative results may require confirmatory assays of greater sensitivity.
Acute Disease ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Caliciviridae Infections/*diagnosis ; Child ; Child, Preschool ; Feces/*virology ; Gastroenteritis/*diagnosis/virology ; Humans ; *Immunoassay ; Infant ; Middle Aged ; Norovirus/*genetics/isolation & purification ; RNA, Viral/analysis ; Reagent Kits, Diagnostic ; Reverse Transcriptase Polymerase Chain Reaction ; Sensitivity and Specificity

The prevalence of human astroviruses was tested in patients with acute gastroenteritis by using conventional duplex reverse transcription (RT)-PCR and electrophoresis. Diarrheal fecal samples were collected from 9,597 patients at local hospitals in Seoul. The prevalence of astroviruses was 1.0% (94/9,597 patients; mostly infants), and that of sapoviruses was 0.1% (14/9,597 patients). Age- and gender-wise analyses were carried out on 29 astrovirus-positive patients having complete information on file regarding their age, gender, and other particulars. The results were higher in patients of ages 0 to 14 yr, and 69.0% of the astrovirus-positive patients were females, of which 69.2% were infants (0 to 12 months), and 61.5% were 1-4 yr old. Notably, in the case of 5 to 78-yr-old acute gastroenteritis patients, 100% were females.
Acute Disease ; Adolescent ; Adult ; Age Factors ; Aged ; Astroviridae Infections/complications/*epidemiology/virology ; Child ; Child, Preschool ; DNA, Viral/analysis ; Feces/virology ; Female ; Gastroenteritis/complications/*diagnosis ; Humans ; Infant ; Male ; Mamastrovirus/genetics/*isolation & purification ; Middle Aged ; Prevalence ; Reverse Transcriptase Polymerase Chain Reaction ; Sapovirus/genetics/isolation & purification ; Sex Factors ; Young Adult

BACKGROUND: We evaluated the analytical and clinical performances of the SD BIOLINE Rota/Adeno Rapid kit (SD Rota/Adeno Rapid; Standard Diagnostics, Inc., Korea), an immunochromatographic assay (ICA), for the simultaneous detection of rotaviruses and adenoviruses in human stool samples. METHODS: We tested 400 clinical stool samples from patients with acute gastroenteritis and compared the ICA results with the results obtained by using ELISA, enzyme-linked fluorescent assays (ELFA), PCR, and multiplex reverse transcription-PCR (mRT-PCR). To assess the analytical performance of the SD BIOLINE Rota/Adeno Rapid kit, we determined its detection limit, reproducibility, cross-reactivity, and analytical reactivity for adenovirus subtypes, and performed interference studies. RESULTS: The overall agreement rates among the tested methods were 91.5% for rotavirus and 85.5% for adenovirus. On the basis of mRT-PCR, the overall agreement, positive agreement, and negative agreement rates of the ICA were 95.6%, 100%, and 94.9% for rotavirus, and 94.0%, 71.4%, and 94.8% for adenovirus, respectively. Using the ICA, we detected all the subtypes of adenovirus tested, but the analytical reactivities for adenovirus subtypes were different between the 4 adenovirus detection methods. The high reproducibility was confirmed, and no cross-reactivity or interference was detected. CONCLUSIONS: The SD BIOLINE Rota/Adeno Rapid kit showed acceptable analytical and clinical performances. However, interpretation of adenovirus positive/negative result should be cautious because of different detectability for adenovirus subtypes among adenovirus detection methods.
Acute Disease ; Adenoviridae/genetics/*immunology/isolation & purification ; Cross Reactions ; DNA, Viral/analysis ; Enzyme-Linked Immunosorbent Assay ; Feces/*virology ; Gastroenteritis/diagnosis/virology ; Humans ; *Immunochromatography ; Multiplex Polymerase Chain Reaction ; RNA, Viral/analysis ; Reagent Kits, Diagnostic ; Reproducibility of Results ; Reverse Transcriptase Polymerase Chain Reaction ; Rotavirus/genetics/*immunology/isolation & purification