Detection Of Norovirus Research Articles

Molecular Study of Torque Teno Virus in Patients with Acute Gastroenteritis.

Torque teno virus (TTV) is a single stranded non enveloped DNA virus. Various studies have found a high prevalence of TTV in different populations and in different human samples including blood and stool. The aim of the present study was to evaluate the prevalence of TTV in adult patients with acute gastroenteritis in stool samples by semi-nested polymerase chain reaction (PCR). This study was a retrospective, cross-sectional study carried out on 100 preserved stool samples from adult patients with simple community acquired diarrhea without dehydration. Stool samples were subjected to antigen detection of rotavirus and norovirus by enzyme linked immunosorbent assay (ELISA). Detection of TTV was performed by the use of semi- nested PCR. The detected viruses were TTV by semi-nested PCR in 83% of the patients, followed by both norovirus and rotavirus in 20% of patients each. TTV was present without any other studied virus in 52% of the samples, the norovirus antigen was detected as a single virus in 2%, and rotavirus was detected as a single virus in 3%. No viruses were detected in 11% of the stool samples. Norovirus was associated with TTV in 17 isolates and as a sole virus in three samples (p = 0.5). Rotavirus was associated with TTV in 17 isolates and alone in three. The data of the present study show a high prevalence of TTV in stool samples from adults with acute gastroenteritis. The presence of rotavirus and norovirus was also a common finding in these patients. There were no detected effects on the clinical features of gastroenteritis associated with the presence of TTV in acute gastroenteritis.

Detection and phylogenetic analysis of norovirus from individual septic tanks in the drainage basin of the coastal area located in the Jaran Bay of Korea

Norovirus (NoV) prevalence was investigated in 100 sewage samples collected from 35 individual septic tanks around the drainage basin of Jaran Bay, Korea in January, May, and July of 2017. Genotypes and diversity of NoV strains detected in sewage samples were also assessed using the conventional RT-PCR and phylogenetic analysis. NoV GI or GII were detected in 22 (22.0%) and 24 (24.0%) samples, respectively. Thirteen genotypes were identified with three dominant genotypes (GI.9, GII.5 and GII.17) and GII.17 showed relatively higher prevalence during the survey period. GII.17 strains were clustered into recombinant type variant or NoV GII.17 Kawasaki variant. NoV GII.17 strains were considered emergent epidemic variants with widespread circulation. NoV surveillance strategy should include both environmental (sewage) and clinical data to reveal minor NoV genotypes likely cause of asymptomatic or underreported infections in the local population.

Detection of feline norovirus using commercial real-time RT-PCR kit for the diagnosis of human norovirus infection.

Feline noroviruses (FNoVs) are potential clinical pathogens in cats. To perform an epidemiological study of FNoV infection, it is necessary to develop a simple and effective method for virus detection. We investigated whether a commercial human NoV quantitative RT-PCR kit for the detection of human NoVs used in medical practice can be applied for FNoV detection. This kit was capable of detecting the FNoV gene regardless of the genogroup (GIV and GVI) in experimental and field samples. Based on the above findings, it is possible to detect FNoVs using human NoV tests. The relationship between FNoV infection and gastroenteritis in cats may be clarified by applying these methods to an epidemiological survey of FNoVs.

Diagnostic Accuracy of Four Commercial Triplex Immunochromatographic Tests for Rapid Detection of Rotavirus, Adenovirus, and Norovirus in Human Stool Samples.

Noroviruses (NoV), rotaviruses (RVA), and adenoviruses (AdV) are the main viral agents responsible for acute gastroenteritis (AGE) in humans. We aimed to determine the diagnostic accuracy of four commercial immunochromatographic tests (ICTs) intended for the rapid and simultaneous detection of these three pathogens. Diagnostic accuracy of bioNexia Noro/Rota-Adeno (bioMérieux), Immunoquick NoRotAdeno (Biosynex), Rota+Adeno+Noro combo card (CerTest Biotec), and Rida Quick Rota/Adeno/Noro Combi (R-Biopharm) ICTs was assessed retrospectively using a collection of 160 stool specimens (including 43 RVA-, 47 AdV-, and 42 NoV-positive samples) from French patients with AGE and using molecular methods as the reference standard. For RVA, the four ICTs demonstrated similar high sensitivity (93%) and excellent specificity (97.4 to 100%). For AdV, the four ICTs demonstrated similar poor sensitivity (54.3 to 58.7%) but excellent specificity (95.5 to 100%). They performed the best in AdV-F species (sensitivity, 80.8 to 84.6%) and worst in AdV non-F species (sensitivity, 22.2 to 27.8%). For NoV, the Rida Quick Rota/Adeno/Noro combi ICT exhibited high sensitivity (87.5%), but the sensitivity of the three others was poor (42.5 to 47.5%). The four ICTs exhibited high specificity (96.6 to 99.1%). Diagnostic accuracy was genogroup dependent. When we tested genogroup I NoV, the Rida Quick Rota/Adeno/Noro Combi ICT presented high sensitivity (90%), while the three other ICTs presented poor sensitivity (10 to 30%); when we tested genogroup II NoV, sensitivity was similar for the four ICTs (65 to 85%). In conclusion, the four ICTs are suitable first-line tests for the rapid diagnosis of RVA infections. The four ICTs are not suitable for the routine diagnosis of AdV infections but could provide a rapid response in case of positivity, notably in the context of AGE. Only the Rida Quick Rota/Adeno/Noro Combi ICT is suitable for the rapid detection of NoV, while the sensitivity for the detection of genogroup I NoV needs to be improved for the 3 other ICTs before being implemented in the routine diagnosis of NoV.

A simple and low-cost paper-based colorimetric method for detecting and distinguishing the GII.4 and GII.17 genotypes of norovirus

In modern times, viruses still threaten people's lives. Among them, norovirus was the main pathogenic factor in the cause of gastroenteritis and foodborne illness, of which the GII.4 and GII.17 genotypes are prevalent in China and most parts of the world. A simple and low-cost platform for rapid and accurate norovirus detection remains a major challenge. After the cell-free system and paper-based chromogenic system were optimized, a rapid and specific norovirus detection method was established based on norovirus-specific sequences in combination with toehold switch elements. The development of a visible color change during detection eliminates the need for any complicated instruments. We validated this strategy and its specificity in differentiating GII.4, GII.17, Zika virus, and human coronavirus HKU1. The results showed that the optimized detection system not only provided a simple and rapid detection method for the sufficient differentiation of the two norovirus genotypes but also showed high specificity and no cross-reactivity with other viruses. Using nucleic acid isothermal amplification, this assay showed a limit of detection of 0.5 pM for the GII.4 genotype and 2.6 fM for the GII.17 genotype in reactions that could be observed directly with the naked eye. Our results suggested that this paper-based colorimetric method could serve as a simple and low-cost visual detection method for pathogens in clinical samples, especially in remote or rural areas.

Evaluation of a rapid immunochromatography (IC) diagnosis kit for the detection of rotavirus and norovirus in diarrheal stool specimens in Bangladesh

Background: Acute gastroenteritis is still the health burden in developed and developing countries. From different etiological agents, viruses are considered to be significant enteropathogens of acute gastroenteritis in children worldwide including Bangladesh. When outbreaks of gastroenteritis occur in communities, rapid identification of viral agents is essential to ensure administration of the appropriate treatment and control. A diagnostic kit with good sensitivity and specificity will help in rapid diagnosis of diarrheal viruses during outbreak. Antivirals are good option of treatment for virus associated diarrhea. Methods and materials: A total of 125 fecal samples were collected between April 2019 and May 2016 from children below 5 y old with acute gastroenteritis from Dhaka in Bangladesh were examined for rotavirus and norovirus by Immunochromatography kit and reverse-transcriptase polymerase chain reaction (RT-PCR). PCR product of specific genes of rotavirus and norovirus were selected for sequence analysis. Results: The immunochromatography kit provide high specificity and sensitivity as well as good agreement with the reference method RT-PCR for the detection of rotavirus and norovirus. Sensitivity of IC kit was found 100% for rotavirus and norovirus. However, IC kit showed 99.13% and 99.17% specificity for rotavirus and norovirus, respectively. 7.2% (9 of 125) samples were found to be positive for rotavirus infection and 3.2% (4 of 125) were positive for norovirus infection by RT-PCR method. We found that G2 (40%) and G9 (40%) were predominant rotavirus strains followed by G1 (20%) among infants and children in Bangladesh. Nucleotide sequence analysis of norovirus indicated that the common GII/7 (100%) strains were circulating among Bangladeshi children and infants. Conclusion: Our findings clearly indicate that the immunochromatography kit provide high specificity and sensitivity as well as good agreement with the reference method RT-PCR for the detection of rotavirus and norovirus. Moreover, IC testa are easy and useful assay for the rapid detection of norovirus among pediatric patients with acute gastroenteritis. This study demonstrated that the IP- Noro/Rota kit proved to be a rapid method for detection of rotavirus and norovirus directly from stool samples and might be useful for screening rotavirus and norovirus during outbreak in Bangladesh.

Detection of human norovirus using next generation sequencing: Strain diversity and expanding whole-genome sequences availability from Brazil

Detection of human norovirus using next generation sequencing: Strain diversity and expanding whole-genome sequences availability from Brazil

Detection of Norovirus in Saliva Samples from Acute Gastroenteritis Cases and Asymptomatic Subjects: Association with Age and Higher Shedding in Stool.

Norovirus infections are a leading cause of acute gastroenteritis outbreaks worldwide and across all age groups, with two main genogroups (GI and GII) infecting humans. The aim of our study was to investigate the occurrence of norovirus in saliva samples from individuals involved in outbreaks of acute gastroenteritis in closed and semiclosed institutions, and its relationship with the virus strain, virus shedding in stool, the occurrence of symptoms, age, and the secretor status of the individual. Epidemiological and clinical information was gathered from norovirus outbreaks occurring in Catalonia, Spain during 2017–2018, and stool and saliva samples were collected from affected and exposed resident individuals and workers. A total of 347 saliva specimens from 25 outbreaks were analyzed. Further, 84% of individuals also provided a paired stool sample. For GII infections, norovirus was detected in 17.9% of saliva samples from symptomatic cases and 5.2% of asymptomatic individuals. Positivity in saliva occurred in both secretors and nonsecretors. None of the individuals infected by norovirus GI was positive for the virus in saliva. Saliva positivity did not correlate with any of the studied symptoms but did correlate with age ≥ 65 years old. Individuals who were positive in saliva showed higher levels of virus shedding in stool. Mean viral load in positive saliva was 3.16 ± 1.08 log10 genome copies/mL, and the predominance of encapsidated genomes was confirmed by propidium monoazide (PMA)xx-viability RTqPCR assay. The detection of norovirus in saliva raises the possibility of oral-to-oral norovirus transmission during the symptomatic phase and, although to a lesser extent, even in cases of asymptomatic infections.

Performance of concanavalin A-immobilized on polyacrylate beads for the detection of human norovirus and hepatitis A virus in fecal specimens.

Quantitative reverse transcription PCR (qRT-PCR) is a sensitive method for the detection of foodborne viruses in fecal samples. However, the performance of qRT-PCR depends on the efficiency of virus concentration methods. In this study, the effect of Concanavalin A (Con A)-immobilized on polyacrylate beads (Con A-PAB) on the qRT-PCR performance, in terms of sensitivity and specificity to detect foodborne viruses in human fecal specimens was compared with commercial viral RNA extraction kit (VRNA). The detection of foodborne viruses by qRT-PCR was validated by viral genome sequencing. Both Con A-PAB and VRNA methods were equally sensitive and specific for detecting hepatitis A virus in fecal specimens. Even though both methods showed high specificity (100% vs. 100%) for detecting human norovirus (HuNoV), Con A-PAB method exhibited higher sensitivity (100% vs. 42.9%) and accuracy (100% vs. 73.3%) compared to VRNA method. In conclusion, the application of Con A-PAB would improve the performance of qRT-PCR for the detection of HuNoV in fecal samples.

Detection of norovirus, hepatitis A and hepatitis E viruses in multicomponent foodstuffs

Among the enteric viruses implicated in foodborne outbreaks, the human norovirus and hepatitis viruses A and E (HAV and HEV) represent a serious public health concern. International standard ISO 15216 proposes methods for detecting HAV and norovirus (genogroups I and II) RNA from soft fruit, leaf, stem and bulb vegetables, bottled water or food surfaces. These methods had not previously been validated for detecting the targeted viruses in other foodstuffs such as multicomponent foods, nor for detecting other viruses in foodstuffs. The aim of this study was to characterise a method derived from the vegetable method described in ISO 15216 to detect HAV, HEV and norovirus in artificially-contaminated multicomponent foodstuffs according to the recent international standard ISO 16140-4.Results showed that the mean recovery rates for all settings did not differ according to the operator. The mean extraction yields ranged from 0.35% to 40.44% for HAV, 5.19% to 100% for HEV, 0.10% to 40.61% for norovirus GI and 0.88% to 69.16% for norovirus GII. The LOD95 was 102 genome copies/g for HAV, HEV and norovirus GII and 103 genome copies/g for norovirus GI. The LOQ was 2.90 × 104, 1.40 × 103, 1.60 × 104 and 1.30 × 104 genome copies/g for HAV, HEV, norovirus GI and norovirus GII respectively. The MNV-1 process control was detected in 120 out of 128 RNA extracts analysed and was recovered with an efficiency of between 3.83% and 50.22%. The mean inhibition rates of quantitative real-time RT-PCR reaction ranged from 3.25% to 28.70% and varied significantly with the type of food matrix. The described method could be used to detect viruses in composite food products for routine diagnosis needs.

Detection and Molecular Characterization of Norovirus in Wastewater in New Orleans

Norovirus is a leading cause of nonbacterial acute gastroenteritis worldwide and has significant morbidity and mortality in low- and middle-income, as well as high-income countries. The present study aimed to determine the genotype distribution of human noroviruses in influent and effluent wastewater at a wastewater treatment plant in New Orleans area. A total of fifteen norovirus genotypes belonging to three genogroups (genogroup I [GI], GII, and GIV) were detected. GI.6 and GII.12 were the most commonly detected norovirus genotypes, and were detected primarily in spring and summer. Three GI genotypes and one GII genotype were detected in effluent, with no apparent seasonal pattern. GII genotypes, which are responsible for the largest proportion of human gastroenteritis cases, were most frequently detected (54.29% of detected genotypes). Four genotypes (GI.1, GI.6, GII.12, and GII.4 Sydney) that cause the majority of human norovirus cases in the United States were detected. The results of the present study demonstrate the importance of environmental and molecular surveillance of norovirus in wastewater in order to mitigate human outbreaks from waterborne transmission, as well as other region-specific routes, such as the consumption of contaminated shellfish.

Extraction of norovirus based on nanomagnetic beads and establishment of a fluorescence quantitative detection method

Norovirus infection is the main cause of epidemic acute gastroenteritis outbreaks. As a result, norovirus merits careful attention. Acute gastroenteritis caused by norovirus is very harmful, necessitating effective prevention and monitoring. This study extracted norovirus using the Fe3O4 nanomagnetic bead method while establishing a rapid and sensitive quantitative norovirus detection method for emergency use. Norovirus RNA was extracted from norovirus-positive stool samples, norovirus-specific primers were designed, and SYBR Green I fluorescent dye was used to construct specific fluorescence quantitative reverse-transcription polymerase chain reaction (RT-PCR) method. Norovirus in the sample was successfully detected with the quantitative RT-PCR method established in this study, with a measured cycle threshold value of 28.73; the melting temperature value of the PCR product was approximately 83.5 °C. Additionally, by analyzing melting curve with quantitative PCR and evaluating the repeatability of the detection method, the performance of the reaction system in terms of specificity and repeatability was determined to be good. The fluorescence quantitative detection method established here can rapidly and effectively detect norovirus, and the method has good specificity and high repeatability. Currently, there is a trend of norovirus infection becoming increasingly severe. Thus, this rapid and sensitive fluorescence quantitative detection method will play a significant role in the monitoring and detection of norovirus and is thus worthy of promotion and application.

Controlling distance, size and concentration of nanoconjugates for optimized LSPR based biosensors

In this report, we have examined the distance- and size-dependent localized surface plasmon resonance (LSPR) between fluorescent quantum dots (QDs) and adjacent gold nanoparticles (AuNPs) to provide a comprehensive evaluation, aiming for practical application in biosensing platform. A series of peptides with different chain lengths, connected between QDs and AuNPs is initially applied to prepare various CdSe QDs-peptide-AuNP systems to optimize LSPR signal. Separation distance between two nanoparticles of these systems before and after conjugation is also confirmed by quantum mechanical modeling and corroborated with their LSPR influenced fluorescence variations. After detailed optimizations, it can be noted that larger sized AuNPs make strong quenching of QDs, which gradually shows enhancement of fluorescence with the increment of distance and the smaller sized AuNPs. Depending on the requirement, it is possible to tune the optimized structure of the CdSe QD-peptide-AuNP nanostructures for the application. In this work, two different structural designs with different peptide chain length are chosen to construct two biosensor systems, observing their fluorescence enhancement and quenching effects, respectively. Using different structural orientation of these biosensors, two nanoconjugates has applied for detection of norovirus and influenza virus, respectively to confirm their application in sensing.

Performance evaluation of Automated Fluorescent Immunoassay System ROTA and NORO for detection of rotavirus and norovirus: A comparative study of assay performance with RIDASCREEN® Rotavirus and Norovirus.

BackgroundThe Automated Fluorescent Immunoassay System ROTA (AFIAS‐Rota) and NORO (AFIAS‐Noro) assays (Boditech Med Inc.) are newly developed diagnostic tests for rotavirus and norovirus infections.MethodsPerformance of AFIAS‐Rota/Noro assays was evaluated in comparison with RIDASCREEN® Rotavirus and Norovirus ELISA kits (R‐Biopharm) using clinical stool samples submitted from November 2018 to January 2019. Multiplex real‐time reverse transcription‐polymerase chain reaction was used as reference method.ResultsA total of 256 clinical specimens were analyzed. AFIAS‐Rota and RIDASCREEN Rotavirus had almost perfect agreement (Kappa value = 0.95), and substantial agreement was observed between AFIAS‐Noro and RIDASCREEN Norovirus (Kappa value = 0.80). For detection of rotavirus, AFIAS and RIDASCREEN assays showed satisfactory diagnostic sensitivity (100% and 97.8%, respectively) and specificity (99.5% and 99.1%). For detection of norovirus, the RIDASCREEN assay showed significantly higher sensitivity than the AFIAS‐Noro (86.0% and 66.0%, respectively; P = .002). Analytic specificity of AFIAS‐Rota/Noro assays showed no cross‐reactivity against any other bacteria (14 strains) or viruses (2 strains). Hands‐on time (6 minutes) and turnaround time (26 minutes) required to perform AFIAS assays were much shorter than those required for RIDASCREEN assays (20 and 150 minutes, respectively).ConclusionThe AFIAS‐Rota/Noro assays showed overall excellent agreement with the RIDASCREEN assays. Although the AFIAS‐Noro assay exhibited lower sensitivity than the RIDASCREEN Norovirus assay for detection of norovirus, the AFIAS‐Rota/Noro assays could be useful as a rapid initial screening test in clinical laboratories due to its convenience and rapid turnaround time.

Molybdenum Trioxide Nanocubes Aligned on a Graphene Oxide Substrate for the Detection of Norovirus by Surface-Enhanced Raman Scattering.

A novel biosensing system based on graphene-mediated surface-enhanced Raman scattering (G-SERS) using plasmonic/magnetic molybdenum trioxide nanocubes (mag-MoO3 NCs) has been designed to detect norovirus (NoV) via a dual SERS nanotag/substrate platform. A novel magnetic derivative of MoO3 NCs served as the SERS nanotag and the immunomagnetic separation material of the biosensor. Single-layer graphene oxide (SLGO) was adopted as the 2D SERS substrate/capture platform and acted as the signal reporter, with the ability to accommodate an additional Raman molecule as a coreporter. The developed SERS-based immunoassay achieved a signal amplification of up to ∼109-fold resulting from the combined electromagnetic and chemical mechanisms of the dual SERS nanotag/substrate system. The developed biosensor was employed for the detection of NoV in human fecal samples collected from infected patients by capturing the virus with the aid of NoV-specific antibody-functionalized magnetic MoO3 NCs. This approach enabled rapid signal amplification for NoV detection with this biosensing technology. The biosensor was tested and optimized using NoV-like particles within a broad linear range from 10 fg/mL to 100 ng/mL and a limit of detection (LOD) of ∼5.2 fg/mL. The practical applicability of the developed biosensor to detect clinical NoV subtypes in human fecal samples was demonstrated by effective detection with an LOD of ∼60 RNA copies/mL, which is ∼103-fold lower than that of a commercial enzyme-linked immunosorbent assay kit for NoV.

A Multisite Network Assessment of the Epidemiology and Etiology of Acquired Diarrhea among U.S. Military and Western Travelers (Global Travelers' Diarrhea Study): A Principal Role of Norovirus among Travelers with Gastrointestinal Illness.

.U.S. military personnel must be ready to deploy to locations worldwide, including environments with heightened risk of infectious disease. Diarrheal illnesses continue to be among the most significant infectious disease threats to operational capability. To better prevent, detect, and respond to these threats and improve synchronization across the Department of Defense (DoD) overseas laboratory network, a multisite Global Travelers’ Diarrhea protocol was implemented with standardized case definitions and harmonized laboratory methods to identify enteric pathogens. Harmonized laboratory procedures for detection of Norovirus (NoV), enterotoxigenic Escherichia coli (ETEC), enteroaggregative E. coli, Shiga toxin–producing E. coli, enteropathogenic E. coli, Salmonella enterica, Shigella/enteroinvasive E. coli, and Campylobacter jejuni have been implemented at six DoD laboratories with surveillance sites in Egypt, Honduras, Peru, Nepal, Thailand, and Kenya. Samples from individuals traveling from wealthy to poorer countries were collected between June 2012 and May 2018, and of samples with all variables of interest available (n = 410), most participants enrolled were students (46%), tourists (26%), U.S. military personnel (13%), or other unspecified travelers (11%). One or more pathogens were detected in 59% of samples tested. Of samples tested, the most commonly detected pathogens were NoV (24%), ETEC (16%), and C. jejuni (14%), suggesting that NoV plays a larger role in travelers’ diarrhea than has previously been described. Harmonized data collection and methods will ensure identification and characterization of enteric pathogens are consistent across the DoD laboratory network, ultimately resulting in more comparable data for global assessments, preventive measures, and treatment recommendations.

Evaluation of three different filters and two methods for recovering viruses from drinking water

Among the enteric viruses implicated in waterborne outbreaks, human norovirus and hepatitis A virus (HAV) are a serious public health issue. Most foodborne viruses are difficult or currently unlikely to cultivate. Because of the lack of a cell culture method, real-time reverse transcriptase PCR is commonly used for the detection of norovirus in foodstuffs and environmental samples. Due to low infectious doses in humans and low virus concentration in water sample, filter adsorption methods were used for concentrating viruses from water. The ISO (Anonymous, ISO 15216-1, 2017) describes standardized molecular methods for detecting HAV and norovirus in bottled water. This method includes a two-step procedure: concentrating the virus using a microporous electropositive filter (47 mm diameter, 0.45 μm pore size) then molecular detection. The Zetapor filter, which had a charged membrane with a pore size of 0.45 μm, was commonly used in the past to concentrate viruses from water or from salad leaves following virus elution. But, unfortunately, the Zetapor filter is no longer marketed and it is therefore necessary to assess an alternative filter. The aim of this study was to compare the ability of two electropositive filters with a pore size of 0.45 μm or 0.22 μm and one uncharged filter (0.45 μm) to recover norovirus and HAV from two different types of drinking water (bottled water and tap water) with the adsorption-elution method proposed by ISO (Anonymous, ISO 15216-1, 2017) (method A) and with direct viral extraction using filters (method B). The mean extraction yields for norovirus and HAV calculated with RNA extracts ranged from 0.2 % – 4.81 % with method A and from 5.05 % – 53.58 % with method B, and did not differ significantly between the two types of drinking water tested. For method B, the mean extraction yields for HAV and norovirus were evaluated according to results from the three filters used. The recovery rate of HAV and norovirus ranged between 3.47 % and 62.41 % with the 0.45 μm electropositive filter and were higher than the other filters. The 0.45 μm electropositive filter could be used to concentrate viruses for routine viral monitoring of drinking water for researchers who want to adopt the method in their lab routine.

Detection of norovirus and rotavirus among inpatients with acute gastroenteritis in a medical center in northern Taiwan, 2013-2018.

Norovirus (NoV) and rotavirus (RV) are among the most common causes of acute gastroenteritis (AGE) of all ages worldwide. There have been scanty reports of the epidemiology data of NoV AGE from clinical virologic laboratory. All stool specimens sent to the virologic laboratory in a medical center in Taiwan for detection of both NoV (by reverse transcription-polymerase chain reaction) and RV (by enzyme immunoassay) from 2013 to 2018 were included for analysis. A total of 15,991 specimens, annually ranging from 2430 in 2017-2915 in 2013, were included. 48.0% and 73.1% of the specimens were obtained from children aged<two years and < five years, respectively. Overall, the positive rate was 13.8% for NoV and 13.2% for RV. Yearly positive rate of NoV ranged from 11.1% to 17.4%. The positive rate in 2018 (17.4%) was significantly higher than that in other study years. NoV positive rate was higher in cold season from January (28.3%), February (23.1%), to March (17.9%) while lower in warm seasons from May to September (less than 10%). By age, NoV positive rate was highest in aged 1-4 years (17.3%) and decreased with age. The yearly positive rate of RV showed a significantly steady decrease from 15.6% in 2013 to 9.1% in 2018 (p<0.001 by trend analysis). In northern Taiwan, NoV, surpassing RV, accounted for one of seven inpatients with AGE during 2013-2018. NoV activity peaked in cold season and children aged <5 years were more commonly encountered.

A photoelectrochemical biosensor for rapid and ultrasensitive norovirus detection

The highly contagious norovirus (NoV) is the most common causative agent of acute gastroenteritis, resulting in >200,000 deaths worldwide annually. A rapid and sensitive detection method is a prerequisite for effective prevention and timely identification of NoV contamination. In the present study, we developed a photoelectrochemical (PEC) biosensor coupled with a novel custom-made monoclonal antibody (mAb) for specific and sensitive NoV detection. Our system could detect levels of recombinant NoV capsid protein VP1 as low as 2 × 10−10 g mL−1 (4.9 pM) within 30 min in a concentration-dependent manner. More importantly, the biosensor was versatile in detecting virus isolated from real samples that were as low as 46 copies μL−1. These findings indicate that this system has the potential to serve as a convenient point-of-care system for diagnosing NoV infection and detecting NoV-contaminated food samples.

Identification of Norovirus Infection in Adults with Acute Gastroenteritis in Jambi, Indonesia

Background: Norovirus (NoV) infection is the most common cause of non-bacterial acute gastroenteritis (AGE), which affects both adults and children. However, study of NoV in adults with AGE in Indonesia is still limited. Objectives: This study aimed to investigate the incidence and clinical characteristics of NoV infection, and also genotype distribution of NoV in adults with AGE in Jambi, Indonesia. Methods: Stool samples were collected from adults (?18 years of age) with AGE at 3 participating hospitals in Jambi from February to April 2019. The detection of NoV and its genotyping were carried out by Reverse Transcriptase PCR and direct sequencing. Results: Of the 44 stool samples collected, 4 (9.1%) were positive for NoV. Four different genotypes were identified, namely GI.2, GII.3, GII.6, and GII.20. All adults with AGE and NoV-positive showed abdominal pain and no dehydration, most of them experienced watery diarrhea (75%) for &lt;5 days and half of them showed vomiting for 1 day. Conclusion: NoV was detected in 9.1% of adults with AGE. The various rare genotypes of NoV in Indonesia were identified in Jambi. The common symptoms in AGE infected with NoV included abdominal pain and watery diarrhea with a short duration. Further surveillance is needed to complete the database of circulating NoV strains for its control.