Analysis of the characteristics of viral infections in children with diarrhea in Beijing from 2018 to 2022 / 中华预防医学杂志

Objective: To explore the characteristics of viral infections in children with diarrhea in Beijing from 2018 to 2022. Methods: Real-time PCR and enzyme-linked immunosorbent assay were used to detect viral nucleic acid of Norovirus (NoV), Sappovirus (SaV), Astrovirus (AstV), Enteric Adenovirus (AdV) or antigen of Rotavirus (RV) in 748 stool samples collected from Beijing Capital Institute of Pediatrics from January 2018 to December 2021. Subsequently, the reverse transcription PCR or PCR method was used to amplify the target gene of the positive samples after the initial screening, followed by sequencing, genotyping and evolution analysis, so as to obtain the characteristics of these viruses. Phylogenetic analysis was performed using Mega 6.0. Results: From 2018 to 2021, the overall detection rate of the above five common viruses was 37.6%(281/748)in children under 5 years old in Beijing. NoV, Enteric AdV and RV were still the top three diarrhea-related viruses, followed by AstV and SaV, accounting for 41.6%, 29.2%, 27.8%, 8.9% and 7.5%, respectively. The detection rate of co-infections with two or three diarrhea-related viruses was 4.7% (35/748). From the perspective of annual distribution, the detection rate of Enteric AdV was the highest in 2021, while NoV was predominant in the other 4 years. From the perspective of genetic characteristics, NoV was predominant by GⅡ.4, and after the first detection of GⅡ.4[P16] in 2020, it occupied the first two gene groups together with GⅡ.4[P31]. Although the predominant RV was G9P[8], the rare epidemic strain G8P[8] was first detected in 2021. The predominant genotypes of Enteric AdV and AstV were Ad41 and HAstV-1. SaV was sporadic spread with a low detection rate. Conclusion: Among the diarrhea-related viruses infected children under 5 years of age in Beijing, the predominant strains of NoV and RV have changed and new sub-genotypes have been detected for the first time, while the predominant strains of AstV and Enteric AdV are relatively stable.

Application of two RT-PCR methods for detection of norovirus in market-sold oysters and norovirus genetic characteristic analysis, a survey conducted in Beijing / 中华流行病学杂志

Objective: To evaluate the application of real-time RT-PCR and semi-nested RT-PCR in the detection of norovirus in oysters and analyzing the genetic characteristics of the isolates. Methods: Real-time fluorescent RT-PCR and semi-nested RT-PCR were used to detect norovirus GⅠ/GⅡ in fresh oysters collected from the markets in Beijing from November 2014 to October 2015. The detection rate of the parallel test was also analyzed. In addition, the reliability of semi-nested RT-PCR was evaluated by agreement rate and consistency test (Kappa value). The positive products of norovirus GⅠ/GⅡ capsid protein region gene by semi-nested RT-PCR were sequenced. Software BioEdit 7.0.9.0 was used for sequence alignment, and software Mega 6.0 was used to construct the evolutionary tree. Results: In 72 samples, the detection rate of norovirus was 31.94% (23/72) by real-time RT-PCR, 38.89% (28/72) by semi-nested RT-PCR and 48.61% (35/72) by parallel test. The coincidence rate of the two methods was 73.61%, a moderate degree (Kappa value =0.43). A total of 13 norovirus strains were successfully sequenced, and 11 strains (7 GⅡ.17 strains, 2 GⅡ. 4 Sydney_ 2012 strains, 1 GⅡ. 1 strain and 1 GⅡ. 21 strain) were obtained from norovirus positive samples by two RT-PCR methods, two strains (1 GⅡ. 17 strain and 1 GⅡ. 3 strain) were obtained from real-time RT-PCR negative samples which were positive for norovirus by semi-nested RT-PCR. The similarity between these strains and reference strains from diarrhea patients, environmental sewage, and shellfish products were 84.4% - 100.0%. Conclusions: The parallel test of norovirus in oysters by two RT-PCR methods can improve the detection rate and detect more genotypes. Norovirus strains in oysters were highly homologous with reference strains from diarrheal patients, environmental sewage, and shellfish products. Therefore, surveillance, prevention and control for norovirus should be carried out in people who have frequent contacts with oysters and related environments.

A molecular epidemiological study of pediatric norovirus gastroenteritis, 2017-2019 / 中国当代儿科杂志

OBJECTIVES@#To study the molecular epidemiological characteristics of norovirus in children with acute gastroenteritis from 2017 to 2019.@*METHODS@#A retrospective analysis was performed on the medical data of children with acute gastroenteritis who were admitted to Children's Hospital of Chongqing Medical University from January 2017 to December 2019. A total of 1 458 stool samples were collected from the children, and viral RNA was extracted. Reverse transcription polymerase chain reaction was used for gene amplification, sequencing, and genotype identification of the VP1 region of capsid protein in norovirus.@*RESULTS@#Among the 1 458 stool samples, 158 (10.8%) were positive for norovirus. There was no significant difference in the positive detection rate of norovirus between different years (@*CONCLUSIONS@#Norovirus GII.4 Sydney 2012 was the major epidemic strain in the children with norovirus gastroenteritis from 2017 to 2019. Although norovirus infection can exist throughout the year, August to October is the peak period. During this period, norovirus surveillance and key population protection are strengthened to help prevent and control norovirus diarrhea.

Absence of norovirus contamination in shellfish harvested and commercialized in the Northeast coast of Brazil

Norovirus (NoV) is the main cause of gastroenteritis outbreaks worldwide. Although NoV spreads mainly from person to person, it is estimated that a large proportion of NoV outbreaks are caused by foodborne transmission. Bivalve mollusks are one of the most important foods involved in NoV transmission to humans. Little is known about NoV prevalence in shellfish harvested and commercialized in Brazil. The aim of this study was to map, for the first time, the distribution of NoV contamination in oysters and mussels harvested and commercialized in the coast of Pernambuco state, northeast Brazil. A total of 380 mollusks (260 oysters and 120 mussels) were collected between February and August 2017 either directly from harvesting areas or obtained from beach vendors at 17 sites in Pernambuco. Samples were processed and tested for NoV contamination using a SYBR Green real-time PCR assay. All samples were negative for NoV GI or GII contamination, suggesting a low risk of NoV contamination from this food source during the study period. Additional surveys in different areas of the Brazilian coast are warranted to monitor the risk of NoV infection upon seafood consumption.

Gastroenteritis aguda por norovirus en pacientes con atención hospitalaria: estudio transversal / Acute gastroenteritis due to norovirus in patients with hospital care: a cross-sectional study

Resumen Introducción: Debido a la disponibilidad de técnicas moleculares en la atención clínica, las gastroenteritis agudas (GEA) por norovirus han retomado importancia como un agente causante de hospitalización. El objetivo de este estudio fue describir las características clínicas y evolutivas de pacientes menores de 16 años hospitalizados por GEA por norovirus. Métodos: Estudio retrospectivo. Se recabó información clínica de los pacientes atendidos en hospitalización del 1 de noviembre del 2016 al 28 de febrero del 2018 por GEA con detección de norovirus (genotipo I y II) en heces por medio de reacción en cadena de la polimerasa con transcriptasa inversa. Resultados: Estudiamos 103 pacientes; 96 (93.2%; intervalo de confianza del 95% [IC 95%]: 86.6-96.7%) con deteccion de genotipo II y 7 (6.8%; IC 95%: 5.3-8.7%) de genotipo I; 76 (73.8%) ≤5 anos. El 48.5% fueron atendidos durante el invierno. La evolucion fue a la autolimitacion en menos de 7 días en todos con manejo hidroelectrolitico. No hubo diferencias en la gravedad y sintomas segun el grupo viral: en ambos predominaron los vómitos (82%). Solo un paciente cursó con perforación intestinal por coinfección con Shigella sp.; tres pacientes (3.1%) manifestaron crisis convulsivas (dos febriles y una epiléptica). Conclusiones: La GEA por norovirus, a pesar de causar una enfermedad meritoria de hospitalización, tiene un pronóstico favorable con autolimitación rápida. Su detección por pruebas rápidas en heces podría evitar la prescripción injustificada de antibióticos.

Abstract Background: Because of the availability of molecular techniques in clinical care, acute gastroenteritis (AGE) due to norovirus has returned to importance as a causative agent of hospitalization. The aim of this study was to describe the clinical features and evolution of patients less than 16 years hospitalized for AGE associated with norovirus. Methods: Retrospective study. Clinical information of the patients attended from November 1, 2016 to February 28, 2018 by AGE with detection of norovirus (genotype I and II) in faeces by means of polymerase chain reaction with reverse transcriptase was collected. Results: We studied 103 patients; 96 (93.2%; 95% confidence interval [95% CI]: 86.6-96.7%) with genotype II detection and seven (6.8%; 95% CI: 5.3-8.7%) genotype I; 76 (73.8%) ≤5 years. 48.5% attended during the winter. The evolution was to self-limitation in less than 7 days in all with hydro electrolytic management. There were no differences in the severity and symptoms according to the viral group; in both cases the vomiting predominated (82%). Only one patient had intestinal perforation due to co-infection with Shigella sp.; three patients (3.1%) manifested seizures (two febrile and one epileptic convulsions). Conclusions: Despite causing a meritorious disease of hospitalization, GEA by norovirus has a favorable prognosis with rapid self-limitation. Its timely detection by rapid tests in feces could avoid the unjustified prescription of antibiotics.

Gastroenterite aguda associada a variantes do Norovírus GII. 4 / Acute gastroenteritis associated with norovirus gii. 4 variants

ABSTRACT BACKGROUND: Norovirus (NoV) is an important etiologic agent of acute gastroenteritis and infects individuals of all ages, especially children in Brazil and worldwide. NoV GII.4 was the most prevalent genotype worldwide because of your extensive genetic diversity. In Brazil, especially in the Northeast, few studies have been developed for identify and molecularly characterize NoV. OBJECTIVE: The present study aimed to detect and describe the molecular epidemiology of NoV associated with acute gastroenteritis. METHODS: The viral RNA extracted from stool samples were subjected to Nested RT-PCR and the genotypes were determined by nucleotide sequences analysis. In total, 278 stool samples assisted at Aliança Hospital in the city of Salvador, with acute gastroenteritis were examined, between March 2009 and July 2012. RESULTS: A high NoV rate (54.2%) was identified in children under 5 years of age. We detected the circulation of different NoV GII.4 variants in Salvador, during the study period as Den Haag 2006b, New Orleans 2009 and Sydney 2012. CONCLUSION: These findings reinforce the need to study the molecular epidemiology of NoV infections in acute gastroenteritis.

RESUMO CONTEXTO: Norovírus (NoV) é o agente etiológico mais importante nas gastroenterites agudas e infecta indivíduos de todas as idades, especialmente crianças no Brasil e no mundo. O NoV GII.4 é o genótipo mais prevalente em todo o mundo devido a sua elevada diversidade genética. No Brasil, principalmente no Nordeste, poucos estudos têm sido desenvolvidos a fim de identificar e caracterizar molecularmente o NoV. OBJETIVO: O presente estudo teve como objetivo detectar e descrever a epidemiologia molecular do NoV associado com gastroenterite aguda. MÉTODOS: RNA viral extraído a de amostras de fezes foi submetido a amplificação por Nested-RT-PCR e o genótipo determinado por analise da sequência de nucleotídeos. Um total de 278 amostras de pacientes atendidos no Hospital Aliança, na cidade de Salvador, com gastroenterite aguda foram examinados, entre março de 2009 a julho de 2012. RESULTADOS: Uma alta taxa de NoV (54,2%) foi identificado em crianças de até 5 anos de idade. Detectou-se a circulação de diferentes variantes de NoV GII.4 em Salvador, durante o período do estudo, tais como Den Haag 2006b, New Orleans 2009 e Sydney 2012. CONCLUSÃO: Estes achados reforçam a necessidade de maiores estudos para esclarecer a epidemiologia molecular das infecções por NoV em casos de gastroenterite aguda.

Molecular screening of blue mussels indicated high mid-summer prevalence of human genogroup II Noroviruses, including the pandemic "GII. 4 2012" variants in UK coastal waters during 2013

Abstract This molecular study is the first report, to the best of our knowledge, on identification of norovirus, NoV GII.4 Sydney 2012 variants, from blue mussels collected from UK coastal waters. Blue mussels (three pooled samples from twelve mussels) collected during the 2013 summer months from UK coastal sites were screened by RT-PCR assays. PCR products of RdRP gene for noroviruses were purified, sequenced and subjected to phylogenetic analysis. All the samples tested positive for NoVs. Sequencing revealed that the NoV partial RdRP gene sequences from two pooled samples clustered with the pandemic "GII.4 Sydney variants" whilst the other pooled sample clustered with the NoV GII.2 variants. This molecular study indicated mussel contamination with pathogenic NoVs even during mid-summer in UK coastal waters which posed potential risk of NoV outbreaks irrespective of season. As the detection of Sydney 2012 NoV from our preliminary study of natural coastal mussels interestingly corroborated with NoV outbreaks in nearby areas during the same period, it emphasizes the importance of environmental surveillance work for forecast of high risk zones of NoV outbreaks.

High prevalence of norovirus in children with sporadic acute gastroenteritis in Manaus, Amazon Region, northern Brazil

BACKGROUND Norovirus (NoV) is a major cause of acute gastroenteritis (AGE) worldwide, especially in children under five years. Studies involving the detection and molecular characterisation of NoV have been performed in Brazil, demonstrating its importance as an etiological agent of AGE. OBJECTIVES The objectives of this study were to investigate the frequency of human NoV and to genotype the strains isolated from 0-14-year-old patients of AGE in Manaus, Brazil, over a period of two years. METHODS A total of 426 faecal samples were collected between January 2010 and December 2011. All samples were tested for the presence of NoV antigens using a commercial enzyme immunoassay kit. RNA was extracted from all faecal suspensions and reverse transcription-polymerase chain reaction (RT-PCR) for the NoV-polymerase partial region was performed as a trial test. Positive samples were then subjected to PCR with specific primers for partial capsid genes, which were then sequenced. FINDINGS NoV was detected in 150 (35.2%) faecal samples, for at least one of the two techniques used. NoV was detected in children from all age groups, with the highest positivity observed among the group of 1-2 years old. Clinically, fever was verified in 43% of the positive cases and 46.3% of the negative cases, and vomiting was observed in 75.8% and 70.8% cases in these groups, respectively. Monthly distribution showed that the highest positivity was observed in January 2010 (81.2%), followed by February and April 2010 and March 2011, when the positivity rate reached almost 50%. Phylogenetic analyses performed with 65 positive strains demonstrated that 58 (89.2%) cases of NoV belonged to genotype GII.4, five (7.7%) to GII.6, and one (1.5%) each to GII.7 and GII.3. MAIN CONCLUSIONS This research revealed a high circulation of NoV GII.4 in Manaus and contributed to the understanding of the importance of this virus in the aetiology of AGE cases, especially in a region with such few studies available.

Caliciviruses in hospitalized children, São Luís, Maranhão, 1997-1999: detection of norovirus GII. 12

ABSTRACT Gastroenteritis is one of the most common diseases during childhood, with norovirus (NoV) and sapovirus (SaV) being two of its main causes. This study reports for the first time the incidence of these viruses in hospitalized children with and without gastroenteritis in São Luís, Maranhão. A total of 136 fecal samples were tested by enzyme immunoassays (EIA) for the detection of NoV and by reverse transcription-polymerase chain reaction (RT-PCR) for detection of both NoV and SaV. Positive samples for both agents were subjected to sequencing. The overall frequency of NoV as detected by EIA and RT-PCR was 17.6% (24/136) and 32.6% (15/46), respectively in diarrheic patients and 10.0% (9/90) in non-diarrheic patients (p < 0.01). Of the diarrheic patients, 17% had fever, vomiting and anorexia, and 13% developed fever, vomiting and abdominal pain. Of the 24 NoV-positive samples, 50% (12/24) were sequenced and classified as genotypes GII.3 (n = 1), GII.4 (6), GII.5 (1), GII.7 (2), GII.12 (1) and GII.16 (1). SaV frequency was 9.8% (11/112), with 22.6% (7/31) in diarrheic patients and 4.9% (4/81) in nondiarrheic (p = 0.04) ones. In diarrheic cases, 27.3% had fever, vomiting and anorexia, whereas 18.2% had fever, anorexia and abdominal pain. One SaV-positive sample was sequenced and classified as GII.1. These results show a high genetic diversity of NoV and higher prevalence of NoV compared to SaV. Our data highlight the importance of NoV and SaV as enteropathogens in São Luís, Maranhão.

Production of Brazilian human norovirus VLPs and comparison of purification methods

Abstract Noroviruses (NVs) are responsible for most cases of human nonbacterial gastroenteritis worldwide. Some parameters for the purification of NV virus-like particles (VLPs) such as ease of production and yield were studied for future development of vaccines and diagnostic tools. In this study, VLPs were produced by the expression of the VP1 and VP2 gene cassette of the Brazilian NV isolate, and two purification methods were compared: cesium chloride (CsCl) gradient centrifugation and ion-exchange chromatography (IEC). IEC produced more and purer VLPs of NV compared to CsCl gradient centrifugation.

Seasonal variation on the presence of adenoviruses in stools from non-diarrheic patients

Human adenoviruses (HAdV), members of the Adenoviridae family, are excreted through the fecal route and may be present in the feces of humans consuming contaminated food or water. The presence of HAdV from different serotypes in the feces of healthy individuals was already reported using conventional polymerase chain reaction; however, real-time PCR (qPCR) may reveal not only the rates of detection as well as demonstrate the viral loads excreted by healthy persons. Aiming to identify and characterize the presence of adenoviruses in stool samples, 147 fecal samples from patients with no records of diarrhea were analyzed (74 from winter season and 73 from summer) by Real-Time PCR (qPCR) assay and conventional PCR. HAdV genome was present in 43.8% (32/73) of stools samples collected during summer season and 21.6% (16/74) during winter. The rate of detection of genomic copies (gc) ranged from 4.04×10² to 6.72×10⁵gc/g of feces among the 147 samples analyzed, of which the ranged of genomic copies of DNA HAdV was major in summer. All samples were negative when tested for rotaviruses (RV) and noroviruses (NoV) by PCR conventional and qPCR respectively. HAdV is excreted constantly by infected individuals in the absence of clinical signs and the occurrence may vary seasonally.

Molecular Characteristics of Noroviruses Genogroup I and Genogroup II Detected in Patients With Acute Gastroenteritis

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 gastroenteritis and enteric viruses in hospitalised children in southern Brazil: aetiology, seasonality and clinical outcomes

Viral acute gastroenteritis (AG) is a significant cause of hospitalisation in children younger than five years. Group A rotavirus (RVA) is responsible for 30% of these cases. Following the introduction of RVA immunisation in Brazil in 2006, a decreased circulation of this virus has been observed. However, AG remains an important cause of hospitalisation of paediatric patients and only limited data are available regarding the role of other enteric viruses in these cases. We conducted a prospective study of paediatric patients hospitalised for AG. Stool samples were collected to investigate human adenovirus (HAdV), RVA, norovirus (NoV) and astrovirus (AstV). NoV typing was performed by nucleotide sequencing and phylogenetic analysis. From the 225 samples tested, 60 (26%) were positive for at least one viral agent. HAdV, NoV, RVA and AstV were detected in 16%, 8%, 6% and 0% of the samples, respectively. Mixed infections were found in nine patients: HAdV/RVA (5), HAdV/NoV (3) and HAdV/NoV/RVA (1). The frequency of fever and lymphocytosis was significantly higher in virus-infected patients. Phylogenetic analysis of NoV indicated that all of these viruses belonged to genotype GII.4. The significant frequency of these pathogens in patients with AG highlights the need to routinely implement laboratory investigations.

Detección de norovirus en niños con diarrea adquirida en la comunidad o nosocomial en el Hospital Guillermo Grant Benavente de Concepción, Chile / Norovirus detection in children with community-acquired or nosocomial diarrhea at Guillermo Grant Benavente Hospital in Concepción, Chile

Introduction: Norovirus (NoV) are RNA viruses highly contagious, stable in the environment, genetically variable, and the most common cause of viral sporadic acute gastroenteritis worldwide. This is the first study carried out in Concepcion, Chile, to investigate the presence of NoV as an etiologic agent of viral diarrheas in hospitalized children. Objective. To detect the presence and genogroup of NoV in children with diarrhea and to compare it with rotavirus (RV) and adenovirus (AdV). Material and Methods: A one year descriptive, prospective study in children 0-14 years old. A single diarrheic stool sample per patient was analyzed for the presence of NoV, RV and AdV. Clinical data were unknown at the moment of sampling. Real time RT-PCR with Taqman™ probes for NoV and the immunocromatography VIKIA™ kit for RoV /AV detection were used. Results: Infection for NoV (25.5%) was significantly higher than for RV (15.9%) and AdV (6.2%). It was even greater in infants younger than 2yr. old (n: 103): NoV 34%, RV 17.5%, AdV 7.8%. Children 2-4 yr. old had 11.8% infection of NoV and RV. Children older than 4, only had 12% RV and 4% AdV. Children hospitalized for diarrhea (n: 92) had: 21.7% of both NoV and RV, and 7.6% AdV; whereas children hospitalized for other causes (n: 53) had 32.1% NoV,5.7% RV and 3.8% AV. The proportion of infection due to NoV was significantly higher in males (31.5%) than in females (19.4%). The average frequency during the year was higher for NoV (30.3%) than for RV (14.7%) except in summer. Conclusion: The presence of NoV was higher than RV in children with diarrhea. NoV infection showed defined characteristics regarding age, gender, seasonal occurrence and nosocomial transmission that are important epidemiological features.

Introducción: Los norovirus (NoV) son virus ARN altamente contagiosos, resistentes, variables genéticamente y una de las etiologías más frecuente de gastroenteritis viral esporádica mundial. Este es el primer trabajo en Concepción, Chile, de búsqueda de NoV como etiología viral de diarreas en niños hospitalizados. Objetivo: Determinar la presencia y genogrupo de NoV en niños con diarrea y compararla con la frecuencia de rotavirus (RV) y adenovirus (AdV). Material y Método: Estudio descriptivo, prospectivo de un año, en niños de 0-14 años ingresados por diarrea aguda o que la adquirieron dentro del hospital. La muestra de deposiciones diarreica se tomó una sola vez por paciente. Las fichas clínicas se analizaron al finalizar el estudio etiológico. Para la detección de NoV se utilizó RPC-TR a en tiempo real con sondas Taqman® y para detección de RV/AdV, el kit VIKIA® de inmunocromatografia. Resultados: La infección por NoV (25,5%) fue significativamente más frecuente que por RV (15,9%) y AdV (6,2%). La mayor presencia de infección fue en pacientes bajo2 años de edad (n: 103): NoV 34,0%, RV 17,5%, AdV 7,8%. La detección en niños hospitalizados por diarrea fue: NoV y RV 21,7% cada uno; AdV 7,6%. En niños con diarrea nosocomial hospitalizados por otras causas se detectó NoV en 32,1%, RV en 5,7% y AdV en 3,8%. La presencia de NoV fue significativamente mayor en varones (31,5%) que en niñas (19,4%). El promedio de diarreas durante el año fue mayor para NoV (30,3%) que para RV(14,7%), excepto en verano. Discusión y Conclusión: La presencia de NoV fue mayor que la de RoV en niños con diarrea y con una tendencia nosocomial que podría deberse a las características del virus que favorece infecciones de ambiente confinado, como hospitales, asilos y cruceros. La infección por NoV presentó características definidas, en edad, género, ocurrencia estacional y relevancia nosocomial, que aportan datos epidemiológicos importantes.

Genotyping of gastroenteric viruses in hospitalised children: first report of norovirus GII.21 in Brazil

This retrospective study (April-September 2003) was designed to investigate the roles of the main viruses responsible for cases of acute infantile gastroenteritis in hospitalised children up to two years of age. The viruses were identified in 64.7% (88/136) of the cases and the detection rates of rotavirus A (RVA), norovirus (NoV) and astrovirus were 41.9% (57/136), 30.3% (24/79) and 12.7% (7/55), respectively. RVA and NoV were detected in 20 of the 24 reported nosocomial infection cases. This study identified the first circulation of the genotype NoV GII.21 in Brazil and highlights the need to establish differential diagnoses through active laboratorial surveillance.

Comparison of primers for the detection of genogroup II noroviruses in India.

Purpose: Noroviruses (NoV) are increasingly recognized as an important cause for acute gastroenteritis, worldwide. Reverse transcription polymerase chain reaction (RT-PCR) and sequencing are the methods of choice for the detection of NoVs, but there is currently no consensus about the primers to be used in these assays. Materials and Methods: In this study, five published primer sets were evaluated for the detection of genogroup II (GII) NoVs in India. The primers target different regions of the NoV genome. Three primer sets detect an NoV in a single round RT-PCR platform, while the remaining two primer sets are based on a nested RT-PCR platform. Result: A panel of 100 samples from previous studies on norovirus diarrhoea in children were tested by all five primer sets. Of them, 74 samples were identified as positive for NoV, by at least one primer set. Subsets of positive amplicons were sequenced to check for specificity. Conclusion: The most sensitive primer set was Girish 2002, which detected GII NoV by nested RT-PCR, and was modified from the previously published primers. This study demonstrates that higher detection can be obtained by either using multiple primer sets or using a sensitive nested RT-PCR assay. It also demonstrates the differences in primer sensitivity for detection of Genogroup II (GII) NoVs in India.

Evaluation of a New Immunochromatographic Assay Kit for the Rapid Detection of Norovirus in Fecal Specimens

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.

Genetic diversity of noroviruses in Brazil

Norovirus (NoV) infections are a major cause of acute gastroenteritis outbreaks around the world. In Brazil, the surveillance system for acute diarrhoea does not include the diagnosis of NoV, precluding the ability to assess its impact on public health. The present study assessed the circulation of NoV genotypes in different Brazilian states by partial nucleotide sequencing analysis of the genomic region coding for the major capsid viral protein. NoV genogroup II genotype 4 (GII.4) was the prevalent (78 percent) followed by GII.6, GII.7, GII.12, GII.16 and GII.17, demonstrating the great diversity of NoV genotypes circulating in Brazil. Thus, this paper highlights the importance of a virological surveillance system to detect and characterize emerging strains of NoV and their spreading potential.

Caracterização molecular de cepas de rotavírus e norovírus: um estudo de 6 anos (2004-2009) / Characterization of rotavirus and norovirus strains: a 6-year study (2004-2009)

OBJETIVO: Monitorar infecções causadas por rotavírus (RV) e norovírus (NoV) em crianças hospitalizadas < 5 anos com gastroenterite aguda provenientes do estado de São Paulo durante um período de 6 anos (2004-2009). MÉTODOS: Este estudo retrospectivo foi realizado em 61 centros médicos, utilizando amostras fecais coletadas por conveniência, analisadas por ensaio imunoenzimático, eletroforese em gel de poliacrilamida, transcrição reversa seguida de reação em cadeia pela polimerase e sequenciamento para caracterização dos genótipos. RESULTADOS: Infecções por RV e NoV foram detectadas em 29,6 por cento (144/487) e 29,2 por cento (26/89) das amostras, respectivamente. Os genótipos de RV detectados com maior frequência foram: G9P[8] em 2004; G1P[8] em 2005; G9P[8] em 2006; e G2P[4] durante os anos de 2007, 2008 e 2009. A taxa de detecção diminuiu de 36,3 por cento (33/91) em 2004 para 4,2 por cento (4/95) em 2009. NoV pertencente ao genogrupo GII foi encontrado em 61,6 por cento (16/26) das amostras, e GI em 11,5 por cento (3/26). Infecções mistas por NoV e RV foram observadas em 2,2 por cento (2/89) das amostras, envolvendo as cepas GI+G9P[8] e GI+G2P[4]. CONCLUSÕES: A distribuição dos genótipos de RV variou com os anos, acompanhada pela redução no número de casos detectados. Ė necessário intensificar a vigilância pós-implantação da vacina contra RV, visando monitorar as cepas circulantes e sua eficácia contra possíveis genótipos emergentes. Os NoVs têm sido cada vez mais identificados como agentes etiológicos relevantes entre crianças hospitalizadas e exercem um papel importante na etiologia viral da gastroenterite pediátrica aguda no estado de São Paulo.

OBJECTIVE: To monitor rotavirus (RV) and norovirus (NoV) infections in hospitalized children < 5 years with acute gastroenteritis in the state of São Paulo, Brazil, during a 6-year period (2004- 2009). METHODS: This retrospective study was conducted with 61 medical centers with convenient surveillance fecal specimens, investigated by enzyme-linked immunosorbent assay, sodium dodecyl sulfate polyacrylamide gel electrophoresis, reverse polymerase chain reaction and sequencing to genotype characterization. RESULTS: RV and NoV infections were detected in 29.6 percent (144∕487) and 29.2 percent (26/89) of the samples, respectively. The most frequent RV genotypes detected were G9P[8] in 2004; G1P[8] in 2005; G9P[8] in 2006; and G2P[4] during 2007, 2008, and 2009. Detection rate declined from 36.3 percent (33∕91) in 2004 to 4.2 percent (4/95) in 2009. NoV genogroup GII was found in 61.6 percent (16/26) of the samples, and GI in 11.5 percent (3/26). Mixed NoV-RV infections were observed in 2.2 percent (2/89) of the samples, involving GI+G9P[8] and GI+G2P[4] strains. CONCLUSIONS: Genotype distribution varied according to collection year, accompanied by a reduction in detection rate. Use of RV vaccine requires implementation of post-marketing surveillance to monitor RV strain diversity and its efficacy against possible new emerging genotypes. NoVs have been increasingly identified as relevant etiological agents among hospitalized children and play an important role in the viral etiology of pediatric acute gastroenteritis in the state of São Paulo.