Virus diversity and an outbreak of group C rotavirus among infants and children with diarrhea in Maizuru city, Japan during 2002-2003

PreK-12 school and citywide wastewater monitoring of the enteric viruses astrovirus, rotavirus, and sapovirus

Wastewater monitoring is an efficient and effective way to surveil for various pathogens in communities. This is especially beneficial in areas of high transmission, such as preK-12 schools, where infections may otherwise go unreported. In this work, we apply wastewater disease surveillance using school and community wastewater from across Houston, Texas to monitor three major enteric viruses: astrovirus, sapovirus genogroup GI, and group A rotavirus. We present the results of a 10-week study that included the analysis of 164 wastewater samples for astrovirus, rotavirus, and sapovirus in 10 preK-12 schools, 6 wastewater treatment plants, and 2 lift stations using newly designed RT-ddPCR assays. We show that the RT-ddPCR assays were able to detect astrovirus, rotavirus, and sapovirus in school, lift station, and wastewater treatment plant (WWTP) wastewater, and that a positive detection of a virus in a school sample was paired with a positive detection of the same virus at a downstream lift station or wastewater treatment plant over 97 % of the time. Additionally, we show how wastewater detections of rotavirus in schools and WWTPs were significantly associated with citywide viral intestinal infections. School wastewater can play a role in the monitoring of enteric viruses and in the detection of outbreaks, potentially allowing public health officials to quickly implement mitigation strategies to prevent viral spread into surrounding communities.

Human adenoviruses in children with gastroenteritis: a systematic review and meta-analysis

PURPOSE

Human adenoviruses (HAdVs) have always been suggested as one of the main causes of gastroenteritis in children. However, no comprehensive report on the global epidemiology of these viruses in pediatric gastroenteritis is available.

METHODS

A systematic search was conducted to obtain published papers from 2003 to 2023 in three main databases PubMed, Scopus, and Web of Science.

RESULTS

The estimated global pooled prevalence of HAdV infection in children with gastroenteritis was 10% (95% CI: 9-11%), with a growing trend after 2010. The highest prevalence was observed in Africa (20%, 95% CI: 14-26%). The prevalence was higher in inpatients (11%; 95% CI: 8-13%) and patients aged 5 years old and younger (9%; 95% CI: 7-10%). However, no significant difference was observed between male and female patients (P = 0.63). The most prevalent species was found to be the species F (57%; 95% CI: 41-72%). The most common HAdVs observed in children with gastroenteritis were types 40/41, 38, and 2. Analysis of case-control studies showed an association between HAdV and gastroenteritis in children (OR: 2.28, 95% CI; 1.51-3.44).

CONCLUSION

This study provided valuable insights into the importance of HAdVs in children with gastroenteritis, especially in hospitalized and younger children. The results can be used in future preventive measurements and the development of effective vaccines.

Molecular Characterization of Rotavirus C from Rescued Sloth Bears, India: Evidence of Zooanthroponotic Transmission

The present study reports the detection and molecular characterisation of rotavirus C (RVC) in sloth bears (Melursus ursinus) rescued from urban areas in India. Based on an RVC VP6 gene-targeted diagnostic RT-PCR assay, 48.3% (42/87) of sloth bears tested positive for RVC infection. The VP6, VP7, and NSP4 genes of three sloth bear RVC isolates (UP-SB19, 21, and 37) were further analysed. The VP6 genes of RVC UP-SB21 and 37 isolates were only 37% identical. The sequence identity, TM-score from structure alignment, and selection pressure (dN/dS) of VP6 UP-SB37 with pig and human RVCs isolates were (99.67%, 0.97, and 1.718) and (99.01%, 0.93, and 0.0340), respectively. However, VP6 UP-SB21 has an identity, TM-score, and dN/dS of (84.38%, 1.0, and 0.0648) and (99.63%, 1.0, and 3.7696) with human and pig RVC isolates, respectively. The VP7 genes from UP-SB19 and 37 RVC isolates were 79.98% identical and shared identity, TM-score, and dN/dS of 88.4%, 0.76, and 5.3210, along with 77.98%, 0.77, and 4.7483 with pig and human RVC isolates, respectively. The NSP4 gene of UP-SB37 RVC isolates has an identity, TM-score, and dN/dS of 98.95%, 0.76, and 0.2907, along with 83.12%, 0.34, and 0.2133 with pig and human RVC isolates, respectively. Phylogenetic analysis of the nucleotide sequences of the sloth bear RVC isolates assigned the isolate UP-SB37 to genotype G12, I2 for RVC structural genes VP7 and VP6, and E1 for NSP4 genes, respectively, while isolates UP-SB19 and UP-SB21 were classified as genotype G13 and GI7 based on the structural gene VP7, respectively. The study suggests that the RVCs circulating in the Indian sloth bear population are highly divergent and might have originated from pigs or humans, and further investigation focusing on the whole genome sequencing of the sloth bear RVC isolate may shed light on the virus origin and evolution.

Worldwide prevalence and genotype distribution of human astrovirus in gastroenteritis patients: A systematic review and meta-analysis

AIM

Human astrovirus (HAstV) is an important causative agent of gastroenteritis in humans, which mainly infects young children and the elderly. The goal of this study was to conduct a meta-analytic review of the prevalence of HAstV amongst patients with gastroenteritis, and to shed light on the connection between HAstV infection and gastroenteritis.

METHODS

Systematic literature searches were conducted to identify all potentially relevant studies recorded up to April 8th, 2022. For study weighting, the inverse variance method was employed and the random-effects model was applied to evaluate data. For case-control studies, the pooled odds ratio (OR) and 95% confidence interval (CI) were calculated to establish the relationship between HAstV infection and gastroenteritis.

RESULTS

Among 302423 gastroenteritis patients from 69 different countries, the overall pooled prevalence of HAstV infection was 3.48% (95% CI: 3.11%-3.89%). Case-control approach was used in 39 investigations, and the overall prevalence of HAstV infection among the 11342 healthy controls was 2.01% (95% CI: 1.40%-2.89%). Gastroenteritis and HAstV infection were associated with a pooled OR of 2.16 (95% CI: 1.72-2.71; P < 0.0001; I² = 33.7%). The most commonly found HAstV genotypes in gastroenteritis patients were HAstV1 (62.18%), HAstV7 (33.33%), and HAstV-MLB1 (17.43%).

CONCLUSION

The frequency of HAstV infection was the highest in children under the age of five, and in developing countries. The prevalence rate of HAstV was not influenced by gender. Semi-nested and nested RT-PCR were highly sensitive assays for detecting HAstV infections.

Global molecular prevalence and genotype distribution of Sapovirus in children with gastrointestinal complications: A systematic review and meta-analysis

Sapovirus (SaV) is an emerging cause of children gastrointestinal complications such as acute gastroenteritis (AGE). The aim of the present systematic review and meta-analysis was to estimate the global prevalence of the SaV in children and association of infection with SaVs and AGE in children based on case-control studies. Four international databases (PubMed, Scopus, Web of Sciences and Google Scholar) were used to retrieve English-language studies published between January 2000 and December 2020. Comprehensive Meta-Analysis software was applied to estimate the overall prevalence, publication bias and heterogeneity index. The pooled prevalence of SaV infection among children with gastroenteritis was 3.4% [95% confidence interval (CI): 2.9%-3.9%] based on a random-effects meta-analysis. Genogroup I was the dominant genogroup of SaV in children with gastroenteritis [2.2% (95% CI: 1.6%-3.0%)], association analysis showed that SaV was associated with gastroenteritis [OR: 1.843 (95% CI: 1.27-2.66)]. Given the significant prevalence of the virus in children, it is necessary to pay more attention to this situation. Therefore, preventive health measures in children should be a priority.

FAST Proteins: Development and Use of Reverse Genetics Systems for Reoviridae Viruses

Reverse genetics systems for viruses, the technology used to generate gene-engineered recombinant viruses from artificial genes, enable the study of the roles of the individual nucleotides and amino acids of viral genes and proteins in infectivity, replication, and pathogenicity. The successful development of a reverse genetics system for poliovirus in 1981 accelerated the establishment of protocols for other RNA viruses important for human health. Despite multiple efforts, rotavirus (RV), which causes severe gastroenteritis in infants, was refractory to reverse genetics analysis, and the first complete reverse genetics system for RV was established in 2017. This novel technique involves use of the fusogenic protein FAST (fusion-associated small transmembrane) derived from the bat-borne Nelson Bay orthoreovirus, which induces massive syncytium formation. Co-transfection of a FAST-expressing plasmid with complementary DNAs encoding RV genes enables rescue of recombinant RV. This review focuses on methodological insights into the reverse genetics system for RV and discusses applications and potential improvements to this system.

Diversity of human sapovirus genotypes detected in Japanese pediatric patients with acute gastroenteritis, 2014-2017

Sapovirus (SaV) is one of the pathogens related to acute gastroenteritis (AGE) in adults and children worldwide. This study reported the diversity of SaV genotypes in children with AGE in Japan from July 2014 to June 2017. Of a total of 2259 stool samples tested by using reverse transcription-PCR method and further analyzed by nucleotide sequencing, 114 (5.0%) were positive for SaV and GI.1 (83.3%) was the most predominant genotype, followed by GII.1, GIV.1, GI.2, GI.3, and GII.3 genotypes. Monthly distribution analysis demonstrated two epidemic peaks from July to December 2015 and February to May 2017. However, no detection peak was observed in 2014 and 2016. Phylogenetic analysis of the complete VP1 nucleotide sequences of these GI.1 strains revealed two major clusters of GI.1 and each of which contained GI.1 strains of both 2015 and 2017. This study suggests that the continuous surveillance of SaV is needed to monitor high genetic diversity in Japanese children with AGE.

The incidence of medically-attended norovirus gastro-enteritis in Japan: Modelling using a medical care insurance claims database

Background

The burden of medically-attended acute gastro-enteritis (MA-AGE) that can be attributed to norovirus is not well established in Japan. Using a nationwide database of medical care insurance claims, we estimated the incidence of medically-attended norovirus-attributable gastroenteritis (MA-NGE) in Japan.

Methods

The incidences of MA-NGE outpatient consultations or hospitalization in Japan were modelled on seasonal patterns of MA-AGE for unspecified causes derived from the Japan Medical Data Center (JMDC) database for the period July 2007 to June 2015.

Results

Mean age-adjusted annual incidence rates (per 10,000 person-years) of MA-NGE associated with outpatient care or hospitalization were 389 (95% CI 269–558) and 13 (95% CI 9–20), respectively. Highest rates were in children under 5 years of age: 1,569 (95% CI 1,325–1,792) for outpatient consultations and 48 (95% CI 39–56) for hospitalizations. Of all gastroenteritis episodes associated with outpatient care or hospitalization, 29% and 31% were attributed to norovirus, respectively. Norovirus was estimated to be responsible for 4,964,000 outpatient visits (95% CI 3,435,000–7,123,000) and 171,000 hospitalizations (95% CI 110,000–251,000) per year across Japan.

Conclusions

Incidence rates of MA-AGE are high in Japan, and norovirus-attributable disease is at least as high as in some other developed countries.

First study conducted in Northern India that identifies group C rotavirus as the etiological agent of severe diarrhea in children in Delhi

BACKGROUND

Group C Rotavirus (RVC) is an enteric pathogen responsible for acute gastroenteritis in children and adults globally. At present there are no surveillance studies on group C Rotaviruses in India and therefore their prevalence in India remains unknown. The present study aimed to evaluate group C rotavirus infection among <5 years old children hospitalized with acute gastroenteritis in New Delhi.

METHODS

A total of 350 fecal specimens were collected during September 2013 to November 2014 from <5 years old diarrheal patients admitted at KSCH hospital, Delhi. The samples found negative for group A rotavirus (N = 180) by Enzyme immunoassay were screened for group C rotavirus by RT-PCR with VP6, VP7 and VP4 gene specific primers. The PCR products were further sequenced (VP6, VP7, VP4) and analyzed to ascertain their origin and G and P genotypes.

RESULTS

Six out of 180 (group A rotavirus negative) samples were found positive for group C rotavirus by VP6 gene specific RT-PCR, of which 3 were also found positive for VP7 and VP4 genes. Phylogenetic analysis of VP7 and VP4 genes of these showed them to be G4 and P[2] genotypes. Overall, the nucleotide sequence data (VP6, VP7 and VP4) revealed a close relationship with the human group C rotavirus with no evidence of animal ancestry. Interestingly, the nucleotide sequence analysis of various genes also indicated differences in their origin. While the identity matrix of VP4 gene (n = 3) showed high amino acid sequence identity (97.60 to 98.20%) with Korean strain, the VP6 gene (n = 6) showed maximum identity with Nigerian strain (96.40 to 97.60%) and VP7 gene (n = 3) with Bangladeshi and USA strains. This is true for all analyzed samples.

CONCLUSION

Our study demonstrated the group C rotavirus as the cause of severe diarrhea in young children in Delhi and provides insights on the origin of group C rotavirus genes among the local strains indicating their source of transmission. Our study also highlights the need for a simple and reliable diagnostic test that can be utilized to determine the disease burden due to group C rotavirus in India.

Group C rotavirus infection in patients with acute gastroenteritis in outbreaks in western India between 2006 and 2014

Faecal specimens collected from outbreak (n = 253) and sporadic (n = 147) cases of acute gastroenteritis that occurred in western India between 2006 and 2014 were tested for group C rotavirus (GCR) using partial VP6 gene-based RT-PCR. All specimens were tested previously for the presence of other viral and bacterial aetiological agents by conventional methods. The rate of GCR detection was 8·6% and 0·7% in outbreak and sporadic cases, respectively. GCR infections prevailed in outbreaks reported from rural areas (10·9%) compared to urban areas (1·6%). Clinical severity score of the patients with GCR infection (n = 23) indicated severe disease in the majority (70%) of cases. The age distribution analysis indicated 52·1% of GCR infections in children aged <10 years. The male:female ratio in GCR-positive patients was 2·3:1. Of the 23 GCR-positive cases, 17 (73·9%) had a sole GCR infection and six had mixed infections with other viral and/or bacterial agents. Phylogenetic analysis of nucleotide sequences classified GCR strains of the study in to I2 genotype of the VP6 gene. This is the first study to show the occurrence of GCR in gastroenteritis outbreaks in India.

Epidemiology of gastroenteritis viruses in Japan: Prevalence, seasonality, and outbreak

Acute gastroenteritis has been recognized as one of the most common diseases in humans and continues to be a major public health problem worldwide. Several groups of viruses have been reported as the causative agents of acute gastroenteritis, including rotavirus, norovirus, sapovirus, human astrovirus, adenovirus, and an increasing number of others which have been reported more recently. The epidemiology, prevalence, seasonality, and outbreaks of these viruses have been reviewed in a number of studies conducted in Japan over three decades. Rotavirus and norovirus were the two most common viruses detected almost equally in children under 5 years of age who were suffering from acute gastroenteritis. Like many other countries, the main rotavirus strains circulating in pediatric patients in Japan are G1P[8], G2P[4], G3P[8], and G9P[8]. Norovirus GII.4 was involved in most outbreaks in Japan and found to be associated with the emergence of new variants Sydney_2012. The classic human astrovirus, MLB, and VA clades astroviruses were also commonly found in pediatric patients with acute diarrhea. The sapovirus and adenovirus have been identified as the minor viral causative agents for acute gastroenteritis in Japan.

Canine rotavirus C strain detected in Hungary shows marked genotype diversity

Species C rotaviruses (RVC) have been identified in humans and animals, including pigs, cows and ferrets. In dogs, RVC strains have been reported anecdotally on the basis of visualization of rotavirus-like virions by electron microscopy combined with specific electrophoretic migration patterns of the genomic RNA segments. However, no further molecular characterization of these viruses was performed. Here, we report the detection of a canine RVC in the stool of a dog with enteritis. Analysis of the complete viral genome uncovered distinctive genetic features of the identified RVC strain. The genes encoding VP7, VP4 and VP6 were distantly related to those of other RVC strains and were putatively classified as G10, P8 and I8, respectively. The new strain was named RVC/Dog-wt/HUN/KE174/2012/G10P[8]. Phylogenetic analyses revealed that canine RVC was most closely related to bovine RVC strains with the exception of the NSP4 gene, which clustered together with porcine RVC strains. These findings provide further evidence for the genetic diversity of RVC strains.

The prevalence of STL polyomavirus in stool samples from Chinese children

BACKGROUND

Over the past 7 years, eleven novel human polyomaviruses (HPyVs) have been identified. The frequent discovery of human polyomaviruses (HPyVs) in the gastrointestinal tract and stool samples suggests a potential involvement in gastroenteritis.

OBJECTIVE

In this study we want to explore the prevalence of STL polyomavirus (STLPyV) in China and delineate the clinical role played by STLPyV.

STUDY DESIGN

Stool samples from 508 hospitalized children with diarrhea and 271 healthy children were screened to detect STLPyV. Human polyomavirus 12(HPyV12), New Jersey polyomavirus (NJPyV-2013) and six common enteric viruses (including rotaviruses, adenovirus, norovirus GI and GII, astrovirus and sapovirus) were also screened in this study.

RESULTS

348 of the 508 (68.5%) specimens from the hospitalized children with diarrhea contained at least 1 common enteric virus. STLPyV was identified in 11 specimens in the case group (2.2%), among which 4 specimens were negative for those common enteric viruses. STLPyV was not more prevalent among the case group than the control group (2.2% versus 3.0%; p = 0.50, χ(2) test). In case group, when common enteric viruses' positive and negative groups were compared, the difference in detection rate of STLPyV was not statistically significant (2.5% versus 2.0%; p = 0.98, χ(2) test). Two whole genome sequences of STLPyV were obtained.

CONCLUSIONS

We are the first to report the prevalence of STLPyV in Chinese children and obtained whole genome sequences of STLPyV strains isolated in China. Our results of phylogenetic analysis support the hypothesis that STLPyV is geographically widespread.

Prevalence of Rotaviruses Groups A and C in Egyptian Children and Aquatic Environment

The objective of this study is to compare the prevalence of rotaviruses groups A and C in Egyptian children and aquatic environment. From 110 stool specimens of children with acute diarrhea and using RT-PCR, 35 samples (31.8 %) were positive for human rotavirus group A and 15 samples (13.6 %) were positive for human rotavirus group C. From 96 samples collected from Zenin wastewater treatment plant over a 2-year period (November 2009-October 2011) and using RT-PCR, rotavirus group A was detected in (4/24) 16.7 %, (5/24) 20.8 %, (4/24) 16.7 %, and (4/24) 16.7 %, while rotavirus group C was detected in (2/24) 8.3 %, (3/24) 12.5 %, (3/24) 12.5 %, and (0/24) 0 % in raw sewage, after primary sedimentation, after secondary sedimentation, and after final chlorination, respectively. Moreover, from 96 samples collected from El-Giza water treatment plant over a 2-year period (November 2009-October 2011), rotavirus group A was detected in (7/24) 29.2 %, (6/24) 25 %, (5/24) 20.8 %, and (3/24) 12.5 %, while rotavirus group C was detected in (3/24) 12.5 %, (1/24) 4.2 %, (1/24) 4.2 %, and (0/24) 0 % in raw Nile water, after sedimentation, after sand filtration, and after final chlorination, respectively. Using SYBR Green real-time RT-PCR, the number of human rotavirus group A genome or infectious units was higher than rotavirus group C. VP6 sequence analysis of the RT-PCR positive rotavirus group C samples revealed that four clinical specimens and three environmental samples showed similar sequences clustered with Moduganari/Human Nigerian strain AF 325806 with 98 % homology, and two clinical specimens and one environmental sample showed similar sequences clustered with Dhaka CB/Human Bangladesh strain AY 754826 with 97 % homology.

Phylogenetic analysis of human group C rotavirus circulating in Brazil reveals a potential unique NSP4 genetic variant and high similarity with Asian strains

Group C rotaviruses (RVC) cause gastroenteritis in humans and animals worldwide, and the evidence for a possible zoonotic role has been recently provided. To gain information on the genetic diversity and relationships between human and animal RVC, we sequenced the VP4, VP7, and NSP4 genes of 12, 19, and 15 human strains, respectively, detected in São Paulo state during historical (1988 and 1993) and recent (2007 and 2008) Brazilian rotavirus surveillance. All RVC strains analyzed in the present study grouped into human genotype (G4-P[2]-E2), and did not show any evidence of animal ancestry. Phylogenetic analysis showed that RVC samples detected in 1988 and 1993 clustered together with strains from distinct continents, indicating that historical RVC strains circulating in São Paulo were closely related to those strains circulating worldwide. All three genes (VP7, VP4 and NSP4) of São Paulo RVC strains isolated in 2007-2008 exhibited close phylogenetic relationship with human RVC strains isolated in China and Japan, suggesting that they are genetically linked, and that a gene flow could be occurring between this Asian countries and Brazil. We identified two distinct clusters in the NSP4 phylogenetic tree. One cluster formed exclusively by human Brazilian strains detected in 1997 and 2003-2004 in Rio de Janeiro, Bahia, and Rio Grande do Sul states (Subgroup II) previously described in a different study, that displayed low sequence identities to other human strains formerly published, and to the Brazilian RVC strains (Subgroup I) characterized in the present study. These data suggests the circulation of two genetic profiles of the NSP4 gene in Brazil. High sequence diversity in NSP4 gene was previously reported in Asia, and additional diversity in NSP4 RVC strains spreading in the world should be expected. More in-depth molecular and epidemiological analysis of human RVC throughout the world will be needed to understand their diversity and clarify their evolution, as well as to develop classifications schemes.

Epidemiological and genetic analysis of human group C rotaviruses isolated from outbreaks of acute gastroenteritis in Yokohama, Japan, between 2006 and 2012

Group C rotavirus (GCRV) infection has been described in several parts of the world, predominantly as sporadic cases of acute gastroenteritis. Little is known about the yearly changes in the GCRV strains from diarrheal outbreaks. Stool samples collected from outbreaks of acute gastroenteritis in Yokohama, Japan, between 2006 and 2012 that were negative for norovirus, sapovirus, and group A rotavirus, were screened for GCRV using a reverse passive hemagglutination method. The GCRV strains were characterized by nucleotide sequence and phylogenetic analysis of their VP6, VP7, VP4, and NSP4 genes. Samples from nine of 735 outbreaks in Yokohama (1 %) contained GCRV, and eight of these outbreaks occurred in primary schools. The nucleotide sequences of the strains detected in this study were more closely related to Asian strains than to those from other regions of the world. The nucleotide sequences of the VP7 gene in these nine strains differed, and yearly changes were observed in the amino acid sequences of the VP4 genes. Phylogenetic trees constructed using the nucleotide sequences of the VP6, VP7, VP4, and NSP4 genes showed that sublineage S1 has divided into S1-1 and S1-2 in the VP4 gene only. Our results confirm that the prevalent strains of GCRV change yearly in Yokohama. This is the first study to demonstrate GCRV-associated gastroenteritis outbreaks in Yokohama, Japan.

Etiological study of enteric viruses and the genetic diversity of norovirus, sapovirus, adenovirus, and astrovirus in children with diarrhea in Chongqing, China

BACKGROUND

Enteric viruses are a major cause of diarrhea in children, especially those <5 years old. Identifying the viral agents is critical to the development of effective preventive measures. This study aimed to determine the prevalence of common enteric viruses in children <5 years old presented with diarrhea to the Children's Hospital of Chongqing Medical University.

METHODS

Five hundred fecal samples were collected between August and November 2010 from children <5 years of age who presented with acute diarrhea at the Children's Hospital of Chongqing Medical University. All samples were tested for rotaviruses A, B, and C, noroviruses GI and GII, adenovirus, sapovirus, and astrovirus using enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction (RT-PCR), or PCR. Partial sequences of norovirus, sapovirus, adenovirus, and astrovirus were phylogenetically analyzed to determine the genotype.

RESULTS

Enteric viruses were detected in 302 of the 500 children who presented with acute diarrhea (277/477; 58.07%) and persistent diarrhea (5/23; 21.74%). In 277 samples from children with acute diarrhea in whom at least one viral agent was found, rotavirus A was the most frequent virus identified (132 cases; 27.67%), followed by norovirus GII in 130 cases (27.25%), adenovirus in 30 cases (6.29%), sapovirus in 9 cases (1.89%) and astrovirus in one case (0.21%). Twenty-two of the norovirus GII-positive cases were randomly selected for genotyping. GII/4 was the predominant strain, followed by GII/6, GII/2, GII/3, and GII/7. Sapovirus was classified into four genotypes: GI/1 was predominant, followed by GI/2, GII/1, and GIV. The predominant adenovirus was type 41. Mixed infections were found in 25 cases, all of which presented with acute diarrhea (25/477; 5.24%). Viruses were positive in 5/23 (21.74%) cases with persistent diarrhea. Neither rotavirus B, rotavirus C, nor norovirus GI were found in any of the samples.

CONCLUSIONS

Enteric viruses are a major cause of diarrhea in children <5 years old in Chongqing. Rotavirus A is the most common etiological agent, follow by norovirus.

Whole-genome analysis of two bovine rotavirus C strains: Shintoku and Toyama

Rotavirus C (RVC) has been detected frequently in epidemic cases and/or outbreaks of diarrhoea in humans and animals worldwide. Because it is difficult to cultivate RVCs serially in cell culture, the sequence data available for RVCs are limited, despite their potential economical and epidemiological impact. Although whole-genome sequences of one porcine RVC and seven human RVC strains have been analysed, this has not yet been done for a bovine RVC strain. In the present study, we first determined the nucleotide sequences for five as-yet underresearched genes, including the NSP4 gene, from a cultivable bovine RVC, the Shintoku strain, identified in Hokkaido Prefecture, Japan, in 1991. In addition, we elucidated the ORF sequences of all segments from another bovine RVC, the Toyama strain, detected in Toyama Prefecture, Japan, in 2010, in order to investigate genetic divergence among bovine RVCs. Comparison of segmental nucleotide and deduced amino acid sequences among RVCs indicates high identity among bovine RVCs and low identity between human and porcine RVCs. Phylogenetic analysis of each gene showed that the two bovine RVCs belong to a cluster distinct from human and porcine RVCs. These data demonstrate that RVCs can be classified into different genotypes according to host species. Moreover, RVC NSP1, NSP2 and VP1 amino acid sequences contain a unique motif that is highly conserved among rotavirus A (RVA) strains and, hence, several proteins from bovine RVCs are suggested to play important roles that are similar to those of RVAs.

Genetic divergence of rotavirus nonstructural protein 4 results in distinct serogroup-specific viroporin activity and intracellular punctate structure morphologies

Nonstructural protein 4 (NSP4) viroporin activity is critical for the replication and assembly of serogroup A rotavirus (RVA); however, the dramatic primary sequence divergence of NSP4s across serogroups raises the possibility that viroporin activity is not a common feature among RVs. We tested for NSP4 viroporin activity from divergent strains, including RVA (EC and Ty-1), RVB (IDIR), and RVC (Cowden). Canonical viroporin motifs were identified in RVA, RVB, and RVC NSP4s, but the arrangement of basic residues and the amphipathic α-helices was substantially different between serogroups. Using Escherichia coli and mammalian cell expression, we showed that each NSP4 tested had viroporin activity, but serogroup-specific viroporin phenotypes were identified. Only mammalian RVA and RVC NSP4s induced BL21-pLysS E. coli cell lysis, a classical viroporin activity assay. In contrast, RVA, RVB, and RVC NSP4 expression was universally cytotoxic to E. coli and disrupted reduction-oxidation activities, as measured by a new redox dye assay. In mammalian cells, RVB and RVC NSP4s were initially localized in the endoplasmic reticulum (ER) and trafficked into punctate structures that were mutually exclusive with RVA NSP4. The punctate structures partially localized to the ER-Golgi intermediate compartment (ERGIC) but primarily colocalized with punctate LC3, a marker for autophagosomes. Similar to RVA NSP4, expression of RVB and RVC NSP4s significantly elevated cytosolic calcium levels, demonstrating that despite strong primary sequence divergence, RV NSP4 has maintained viroporin activity across serogroups A to C. These data suggest that elevated cytosolic calcium is a common critical process for all rotavirus strains.

Monitoring of group C rotavirus in children with acute gastroenteritis in Brazil: an emergent epidemiological issue after rotavirus vaccine?

Group C rotavirus (GpCRV) has a worldwide distribution; however, its epidemiology and ecology are still unclear. Evidence for a possible zoonotic role has been postulated recently for Brazilian children strains. The aim of this study was to monitor GpCRV in children ≤15 years with acute gastroenteritis during the 2007-2010 national Brazilian rotavirus surveillance, and to undertake the molecular characterization of the major VP6 capsid protein. A total of 3,019 fecal samples were first screened for Group A rotavirus (GpARV). A total of 2,205 GpARV ELISA negative samples were tested further for the presence of GpCRV by SDS-PAGE, electronic microscopy, and RT-PCR for the VP6 gene. The genetic diversity of GpCRV was carried out by sequencing the VP6 gene. GpARV and GpCRV infections were detected in 24.6% (742/3,019) and 0.3% (8/3,019), respectively. The GpCRV detection rate increased from 0.2% (1/422) in 2007 to 1% (7/708) in 2008, and GpCRV cases were not detected in 2009 and 2010. The phylogenetic analysis indicated that the strains belonged to the human lineage, and showed a genetic relationship with the GpCRV strain from Japan isolated in 2009. None of the study sequences was related closely to animal GpCRV strains. This study provides further evidence that GpCRV is a minor cause of acute childhood gastroenteritis in Brazil, and does not suggest that GpCRV may assume epidemiological importance in the future, even after the introduction of a GpARV vaccine. In addition, the molecular analyses of the GpCRV samples in this study do not support the zoonotic hypothesis.

Genomic evolution, host-species barrier, reassortment and classification of rotaviruses

Evaluation of: Yamamoto D, Ghosh S, Ganesh B et al.: Analysis on genetic diversity and molecular evolution of human group B rotaviruses based on whole genome segments. J. Gen. Virol. 91(Pt 7), 1772–1781 (2010). Rotaviruses are members of the Reoviridae family, causing severe diarrheal illness and death in humans and animals. They have been subdivided into at least seven serological groups (A–G), and, recently, a new rotavirus known as ‘new adult diarrhea virus’ or ADRV-N was discovered. Only in group A rotaviruses have a substantial number of strains been analyzed completely on the molecular level. For groups B, C and ADRV-N rotaviruses a very limited number of complete genomes are available, and for group D, E and F no sequence data are available at all. Here, Yamamoto and colleagues describe the full genomic characterization of four human group B rotaviruses isolated in India, Bangladesh and Myanmar. These four strains were analyzed phylogenetically and individual gene segments were compared with their group A and C counterparts, indicating that functionally important motifs and structural characteristics were conserved. This study, together with others, highlights the need for complete genome analysis of rotaviruses, in order to study their genetic evolution, the occurrence of reassortments, crossing of the host-species barrier and their classification. Upcoming new mass sequencing technologies are expected to speed up the process of filling in the gaps in our data.

Detection and characterization of group C rotavirus in Buenos Aires, Argentina, 1997-2003

The role of group C rotaviruses as a cause of diarrhea was examined among children <17 years of age admitted to a Hospital in a suburban area of Buenos Aires, Argentina between 1997 and 2003. A total of 1,579 fecal samples were screened for group A (RVA) and C (RVC) rotaviruses by two in-house ELISA methods at Quilmes University (UNQ-ELISA). Samples positive, doubtful and negative by RVC specific UNQ-ELISA (n = 246) were examined further for RVC by another in-house ELISA (CDC-ELISA), electron microscopy, RT-PCR, nested PCR, and Southern hybridization. Sensitivity, specificity, and predictive values for each test were determined. While the sensitivity was comparable for the nested PCR and CDC-ELISA methods (82.5%), the molecular methods were slightly more specific. Poorly preserved particles were often seen in fecal samples, suggesting that degradation of RNA could be a factor influencing the performance of molecular methods. The incidence of RVC was estimated to be 3% without apparent differences among seasons. RVC infected patients had a significantly (P < 0.001) higher median age (6 years vs. 1 year) than those with RVA infection. Sequence of the RVC VP7 gene from six Argentinean strains and sequences reported previously in different countries showed high nucleotide (94.4-99.9%) sequence identities, indicating a high degree of conservation for human RVC VP7 genes among strains collected on five continents over a period of 17 years. These findings indicate that RVC is a significant cause of diarrhea and it is necessary to develop simple and sensitive serological methods for its detection.

[Use of the recombinant baculovirus BacVP6C for the construction of an internal positive control of rotavirus C]

AIMS

Unlike group A, a few studies have interested other groups of the rotavirus, especially in Tunisia. The role of rotavirus C (RVC) infection is underestimated because of its sporadic nature. The aim of our study was to develop rapid diagnostic procedures of RVC by using an internal positive control of reverse transcription PCR (RT-PCR).

METHODS

The internal positive control (386pb) was designed from the recombinant baculovirus BacVP6C containing the full length cDNA of the Cowden strain gene 5 (1353pb). A fragment of 596pb was amplified by PCR using the BacVP6C DNA ds as template. Then, a central part of 210pb was deleted and the remaining fragment (386pb) was cloned into pGEM-3Zf(+) plasmid between SP6 and T7 RNA polymerase promoters.

RESULTS

The obtained recombinant plasmid "pIAM1" was then used for the generation of the internal positive control by in vitro transcription. The sensibility of the RT-PCR was about 3.66×10(5) molecules of RNA/μl.

CONCLUSION

The use of a shorter positive control, as compared to the wild type, allows increased specificity of the RT-PCR reaction, and could be used for efficient diagnostic and surveillance of RVC-caused diseases.

Molecular characterization of rotaviruses, noroviruses, sapovirus, and adenoviruses in patients with acute gastroenteritis in Thailand

Outbreaks of viral gastroenteritis occur worldwide including Thailand. Unfortunately, there is limited information since etiologic agents have not been identified in several outbreaks of nonbacterial gastroenteritis. The genotype of enteric viruses causing acute gastroenteritis in Thailand was determined using reverse transcription-multiplex polymerase chain reaction and DNA sequencing. From January 2006 to February 2007, stool samples were collected from patients with acute gastroenteritis of all age groups attending a hospital in Thailand, and patients with nonbacterial acute gastroenteritis (262 patients) were tested for enteric viruses. The overall positive detection rate of enteric viruses was 14.9%; group A rotaviruses (6.1%), noroviruses (6.5%): GI (0.8%) and GII (5.7%), adenoviruses (1.5%), and sapoviruses (0.8%) were found. Group B and C rotaviruses, and astroviruses were not detected in the enrolled patients. Viral acute gastroenteritis occurred in children less than 15 years of age (25.2%, 33/131) with higher frequency than in adults (4.6%, 6/131), P-value <0.001. Rotavirus G1 was the most predominant genotype, followed by G3, and G9. Among noroviruses, GI-2 was identified; whereas, GII was predominant with a high frequency of GII-4 observed, followed by GII-16, GII-2, GII-3, and GII-12. Sapovirus GII-3 and human adenoviruses were identified. This study suggests that enteric viruses play an essential role in patients with acute gastroenteritis attending hospital and mainly in children who have a higher prevalence of group A rotaviruses and noroviruses. The genetic analyses provide molecular epidemiological data for viruses important to public health.

Molecular epidemiology of adenovirus infection among infants and children with acute gastroenteritis in Dhaka City, Bangladesh

A total of 917 fecal specimens collected from infants and children with acute gastroenteritis in Dhaka City, Bangladesh during 2004-2005 were examined for the presence of adenoviruses by PCR. Adenoviruses were identified in 17 of 917 (1.9%) specimens. Detected adenoviruses were subjected to molecular genetic analysis by sequencing method. Adenoviruses detected in this study were classified into three serotypes, namely Ad9, Ad10 and Ad40. Of these, Ad40 was predominant, followed by Ad9 and accounted for 42% (7 of 17) and 36% (6 of 17), respectively. This is the first report of acute gastroenteritis attributed to Ad9 and Ad10 in Dhaka City, Bangladesh. Another interesting feature of the study was absence of Ad41 serotype. Our results clearly indicated that adenovirus infections were most commonly observed in winter season (October 2004 through January 2005) and in rainy season (May 2005 through July 2005) in Dhaka City. The most common clinical symptoms of adenovirus-infected patients were dehydration (94%), abdominal pain (59%) and vomiting (30%). To our knowledge, this is the first 1-year molecular epidemiological research of adenovirus infection in Bangladesh.

Viral agents associated with acute gastroenteritis in children hospitalized with diarrhea in Lanzhou, China

BACKGROUND

Gastroenteritis is a major cause of childhood morbidity and mortality worldwide. Rotavirus, human caliciviruses (HucV), adenovirus, and astrovirus are recognized as common etiologies of acute gastroenteritis.

OBJECTIVES

To use antigen detection and molecular methods to determine the viral etiology of childhood diarrhea in Lanzhou, China, 2005-2007.

STUDY DESIGN

544 stool specimens were collected from children hospitalized with diarrhea. ELISA, RT-PCR, or PCR were used to detect viruses commonly causing diarrhea.

RESULTS

Group A rotavirus, norovirus, sapovirus, astrovirus, and adenovirus, were detected in 54.0%, 9.2%, 1.1%, 3.3%, and 4.4%, respectively. No group B or group C rotaviruses were detected. The relative contribution of these viruses changed greatly over 2 years. The percentage of rotavirus and adenovirus dropped from 61.2% and 5.4% to 47.6% and 1.4%, whereas HucV increased from 5.0% to 15.0%. G1 and P[8] were the predominant rotavirus strains, and P[6] was detected for the first time in this area. The predominant norovirus strain changed from GII3 to GII4, and the subtypes of GII4 changed from the Hunter strain to the variant 2006b strain.

CONCLUSIONS

The distribution of viruses and genotypes of individual viruses causing gastroenteritis in Lanzhou, China changed greatly during 2005-2007.

Human bocavirus in children hospitalized for acute gastroenteritis: a case-control study

Background. Human bocavirus (HBoV) was recently discovered in children with respiratory tract disease and gastroenteritis. The causative role of HBoV in human gastroenteritis remains uncertain, and, to our knowledge, no previous case-control study has studied the relationship between HBoV and gastroenteritis.

Methods. We conducted a case-control study that examined stool samples from 397 children with diarrhea and from 115 asymptomatic control subjects. HBoV was detected using polymerase chain reaction. Real-time polymerase chain reaction was used to quantify the HBoV loads in case and control groups. Common enteric viruses were examined using enzyme-linked immunosorbent assays, polymerase chain reaction, and reverse-transcription polymerase chain reaction.

Results. At least 1 viral agent was discovered in 60.2% of cases. HBoV was detected in 14 samples, and 9 were coinfected with either rotavirus (7 of 14 samples) or human calicivirus (2 of 14). Many (8 [57.1%] of 14) of the HBoV infections occurred during September-December 2006. Most (12 [85.7%]) of the HBoV-infected children were 7–18 months of age. The percentage of children with HBoV infection did not differ significantly between case patients and control subjects (3.5% vs. 3.5%), and the statistical analysis did not support a correlation between HBoV infection and more-severe clinical symptoms. The viral load differences between the 2 groups were not statistically significant (P = .09, by log-normal Student's t test). In addition, the VP1/VP2 partial gene of HBoV from case patients and control subjects showed minimal sequence variation.

Conclusions. A single genetic lineage of HBoV was revealed in persons in China. Despite its high prevalence in stool samples, our study does not support a causative role of HBoV in gastroenteritis.

Evidence for zoonotic transmission of group C rotaviruses among children in Belém, Brazil

The prevalence and potential zoonotic transmission of group C rotavirus (RVC) were examined by testing fecal samples collected from children during a longitudinal study that was carried out in the outskirts of Belém, Brazil, from December 1982 to March 1986. The study involved a group of 30 children who were followed from birth to 3 years. Of the 77 samples tested from 29 children, 5 (6.5%) were positive for human and 3 (4%) for porcine RVC by using nested PCR assay with primers specific for VP6 gene of human or porcine RVC and by Southern hybridization using a probe specific for VP6 gene of both human and porcine RVC. In addition, a total of 59 fecal specimens from the 30th child were tested, 1 (1.7%) and 14 (23.7%) were positive for human and porcine RVC, respectively. Partial nucleotide sequences of VP6 gene demonstrated that the six human strains detected in Brazil were homologous with other human RVC, and 14 of the 17 porcine RVC strains examined showed a complete homology among themselves but differed slightly from the porcine Cowden strain, suggesting that a single porcine RVC strain was circulating in Belém. This study is the first to provide evidence for transmission of RVC from swine to human. They also indicate that both human and porcine RVC were endemic in Belém.

Prevalence of group C rotavirus among children in Rhode Island, United States

BACKGROUND

Group C rotavirus causes sporadic cases and outbreaks of acute diarrhea in humans but its burden as a cause of severe gastroenteritis in children remains unclear.

OBJECTIVES

To investigate the epidemiology and burden of group C rotavirus gastroenteritis among children in Rhode Island, United States.

STUDY DESIGN

Diarrhea stool specimens from 124 children < or =10 years of age were collected, screened for group C and A rotavirus by EIA specific for each group, and further examined by nested PCR and Southern hybridization using primers and probes specific to the VP7 gene of human group C rotavirus. Group C rotavirus-positive fecal specimens were also examined by EM.

RESULTS

Rotavirus was detected in 73 (59.0%) of 124 fecal samples. These included 53 (42.7%) positive for group A, 5 (4.0%) for group C and 15 (12.1%) for both group A and C rotaviruses. Examination of group C-positive samples by EM revealed the presence of largely empty or damaged rotavirus-like particles.

CONCLUSION

These findings indicate that group C rotavirus is an important cause or a contributing cause of diarrhea among infants and older children in Rhode Island, United States.

Detection and quantification of group C rotaviruses in communal sewage

Group C rotaviruses have been recognized as a cause of acute gastroenteritis in humans, cattle, and swine, although the true epidemiologic and clinical importance of this virus in these hosts has not yet been fully established. A real-time PCR assay based on a broadly reactive primer pair was developed and used to quantitatively determine the viral load of group C rotaviruses in environmental samples. A total of 35 raw and 35 treated sewage samples collected at the same sampling time in four Hungarian sewage treatment plants during a survey in 2005 were tested for the presence of group C rotaviruses. The overall detection rates were 91% (32 of 35) for the influent and 57% (20 of 35) for the effluent samples. Molecular characterization of the amplified partial VP6 gene revealed the cocirculation of human and animal (i.e., bovine and porcine) strains that were easily distinguishable by melting curve analysis. Human strains yielded relatively high viral loads (mean, 1.2 x 10(7); median, 6.9 x 10(5) genome equivalents per liter influent sewage) and appeared to display seasonal activity over the study period, whereas animal strains appeared to circulate throughout the year at much lower average titers (bovine strains mean, 9.9 x 10(4); median, 3.0 x 10(4); porcine strains mean, 3.9 x 10(4); median, 3.1 x 10(4) genome equivalents per liter influent sewage). Our findings suggest that monitoring of communal sewage may provide a good surrogate for investigating the epidemiology and ecology of group C rotaviruses in humans and animals.

Quantitative detection of sapoviruses in wastewater and river water in Japan

AIMS

To detect sapoviruses at a wastewater treatment plant (WWTP) and in a river in Japan, quantitatively.

METHODS AND RESULTS

Influent and effluent samples at a WWTP and river water samples were collected monthly for 1 year. The water samples were subjected to virus concentration using an HA electronegative filter, followed by quantification of sapoviruses using real-time PCR. The concentration of sapoviruses in influent ranged from 2.8 x 10(3) to 1.3 x 10(5) copies per litre, showing a higher value in winter. Seven (58%) of 12 effluent samples were positive for sapoviruses, as were 23 (64%) of 36 river water samples collected from three sites along the Tamagawa River.

CONCLUSIONS

Sapoviruses were abundant in the influent even in the nonepidemic period, suggesting that sporadic and asymptomatic infections occur throughout the year. Increasing concentration of sapoviruses was discharged into the river during the epidemic period winter.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study demonstrating the quantitative detection of sapoviruses in aquatic environments.

Diversity of viruses associated with acute gastroenteritis in children hospitalized with diarrhea in Ho Chi Minh City, Vietnam

A molecular epidemiological study on common diarrheal viruses was conducted in Ho Chi Minh City, Vietnam between October 2002 and September 2003. Fecal samples were collected from 1,010 hospitalized children with acute gastroenteritis. Those samples were screened for groups A, B, and C rotavirus, adenovirus, genogroups I and II norovirus (NoV), sapovirus (SaV), and human astrovirus (HAstV) by RT-multiplex PCR, and the positive specimens were characterized further by ELISA, nested PCR, or sequencing. Among the diarrheal viruses detected, group A rotavirus was the most common, with a proportion of 67.4%, whereas NoV GII, adenovirus, SaV, and HAstV were also found in 5.5, 3.2, 0.8, and 0.6%, respectively. It is noteworthy that the group C rotavirus was first reported in Vietnam, with a proportion of 0.5% in this study. Fifty-six of 1,010 (5.5%) samples were found positive with more than one viral agent, in which 25 samples contained both group A rotavirus and NoV GII. Group A rotavirus could be identified throughout year with the peaks in both the dry and rainy season, whereas other viruses prevailed mainly in the rainy season. G-typing for the group A rotavirus showed that genotype 1 was still the most prevailing (33.0%), but interestingly, serotype 9 was emergent and became the third most common rotavirus G-type in these samples (13.7%). The four most common G-P combinations globally, G1P[8], G2P[4], G3P[8], and G4P[8] were found in 46.8% of rotavirus-positive samples, and it is of interest that one unusual rotavirus G9P[19] strain was first detected in Vietnam. The majority of NoV strains belonged to GII/4, and SaV strains mainly clustered with the Manchester strain (GI/1). Twenty-seven out of 32 adenovirus strains were identified as serotype 41. All HAstVs belonged to genotype 1. The results indicated clearly the impact of viral agents causing gastroenteritis and the importance of vaccination against diarrhea in Vietnam.

An outbreak of adenovirus serotype 41 infection in infants and children with acute gastroenteritis in Maizuru City, Japan

A total of 337 fecal specimens were collected from infants and children with acute gastroenteritis in Maizuru City, Japan from July 2004 to June 2005 and tested for the presence of rotavirus, norovirus, sapovirus, astrovirus, and adenovirus by RT-multiplex PCR. Among diarrheal viruses detected, norovirus was the most prevalent (13.6%, 46 of 337), followed by adenovirus (8%, 27 of 337), group A rotavirus (5%, 17 of 337), astrovirus (1.8%, 6 of 337), and sapovirus (1.8%, 6 of 337), respectively. Adenovirus was subjected to molecular genetic analysis by sequencing. Adenovirus detected in this study was classified into five serotypes, namely Ad1, Ad2, Ad3, Ad5, and Ad41. Of these, Ad41 was the most predominant serotype that accounted for 85.2% (23 of 27). It was noteworthy to point out that Ad41 infection was apparently confined only to the period of 4 months (October 2004 through January 2005). This pattern of infection implied the outbreak of Ad41 in these subjects, which was the first outbreak of acute gastroenteritis attributed to adenovirus in Maizuru City, Japan. Another interesting feature of the study was the existence of two Ad41 subtypes co-circulating in this outbreak. This report confirmed the presence of adenovirus as one of an important cause of acute gastroenteritis among Japanese infants and children.

Prevalence and molecular characterization of human group C rotaviruses in Hungary

BACKGROUND

Group C rotaviruses are recognized enteric pathogens of humans and animals. Human group C rotaviruses have been associated with sporadic episodes and large outbreaks of gastroenteritis in children and adults but their epidemiology and ecology are still unexplored.

OBJECTIVES

To collect epidemiological data on group C rotavirus infections among children with gastroenteritis in Hungary and perform molecular characterization on the identified strains.

STUDY DESIGN

Fecal samples were collected during the 2003 surveillance in Baranya County, Hungary. The presence of group C rotavirus RNA was investigated by polyacrylamide gel electrophoresis and by reverse transcription-nested polymerase chain reaction for the VP6 gene. The identified strains were further characterized by sequencing and phylogenetic analysis of the VP7, VP6, VP4, and NSP4 genes.

RESULTS

Three of 472 samples (0.6%) tested positive for group C rotavirus. Two samples were selected for molecular analysis. Strains BaC 6104/03 and BaC 11549/03 displayed an overall identity of >99.8% and 99.3% at the nucleotide and amino acid level, respectively. The VP7 of the strain BaC 6104/03 was most closely related (99.5% aa) to the Nigerian strain Jajeri, while the VP4s of strains BaC 6104/03 and BaC 11549/03 were more similar (98.1% aa) to strains Belem and 208, detected in Brazil and China, respectively.

CONCLUSIONS

Based on this 1-year study, we conclude that group C rotaviruses are not of epidemiological relevance in the etiology of childhood acute gastroenteritis in Hungary. The low sequence divergence between the Hungarian strains suggested that a single group C rotavirus strain circulated in this period in the study area.

The detection of human sapoviruses with universal and genogroup-specific primers

Sapovirus (SV) causes gastroenteritis in humans and comprises genetically divergent viruses. A nested reverse transcription-polymerase chain reaction (RT-PCR) targeting the capsid-protein-coding region was developed using universal and genogroup-specific primer sets. The universal primers were capable of detecting human SV genogroups I, II, IV and V. Genetic analysis of the amplified products enabled us to phylogenetically determine the genotypes of the viruses. In addition, genogroup-specific primers that amplified different lengths of the amplicon depending on the genogroup were developed. These genogroup-specific primers were also used as inner primers for the nested PCR. These two simple RT-PCR methods are powerful tools for both detection and epidemiological studies of human SV.

RT-PCR based diagnosis revealed importance of human group B rotavirus infection in childhood diarrhoea

BACKGROUND

Human group B rotavirus was first identified as causative agent of a large outbreak of severe gastroenteritis affecting more than 1 million people, predominantly adults in China in 1982-1983. In spite of serological evidences for the presence of group B rotavirus in many countries of the world, the virus has been detected only from China, India and Bangladesh, where most of the cases were from adults.

OBJECTIVES

To ascertain the role of group B rotavirus as an aetiological agent of diarrhoea among children in Kolkata, India.

STUDY DESIGN

An active surveillance was conducted for rotavirus infection in children in a leading referral paediatric hospital and a few samples were also collected from adults of another hospital in Kolkata, India over a period of 3 years (2002-2004). After primary screening of rotaviruses by RNA electrophoresis in polyacrylamide gel, 200 of 412 samples negative by PAGE were screened by reverse transcription polymerase chain reaction for group B rotaviruses. The group B rotavirus positives samples were also confirmed by dot-blot hybridization.

RESULT

During the study period, we detected 37 (18.5%) sporadic cases of human group B rotavirus infection in children below 3 years of age of which 15 (7.5%) showed mixed infection with group A rotaviruses by RT-PCR. In dot-blot hybridization studies the RNA of all rotavirus positive samples hybridized with the nonisotopic psoralen-biotin labeled total RNA probe generated from a human group B rotavirus CAL-1 strain confirming the samples as group B rotaviruses.

CONCLUSION

The shift in age preference of group B rotavirus infection from adult to children and mixed infection of group B and group A rotaviruses reveals the importance of group B rotavirus as an etiological agent of childhood diarrhoea. Therefore, future vaccination strategy should include both group A and B rotaviruses to control rotavirus diarrhoea.

First experience with diagnosing astroviral infections in children hospitalized in Pilsen (Czechia)

Between the years 2000-2002 astroviral infection was confirmed in 0.8 % of 2606 children admitted for a diarrheal disease to the University Hospital in Pilsen (Czechia). Astrovirus infections most frequently occurred in the age group between 49-60 months, and 77.3 % of the infections occurred in winter. When the incidence was calculated for these most susceptible age groups, the positive rates were 2.4 % (between 49-60 months) and 1.2 % (between 7-12 months) respectively. On average the hospitalization lasted for 5 d, the diarrhea 3.7 d, vomiting 1.1 d, and 40.9 % of infected children had a raised temperature. In 7 out of 872 stool samples (0.8 %), astrovirus antigen has appeared in the course of the monitored period, i.e. nosocomial astrovirus infection was recorded. In view of the rarity of detecting astroviral infections it is probably not effective to include the diagnosis of these infections in the routine panel when examining the children admitted for gastrointestinal infections. The diagnosis of these infections should, however, be performed within the framework of epidemic incidence and in nosocomial infections.

First detection of group C rotavirus in patients with gastroenteritis in Slovenia

Group C rotaviruses are associated with sporadic gastroenteritis and outbreaks of diarrhea in children and adults worldwide. Three cases with group C rotavirus infection are described, and the molecular characterization of the gene for the major capsid protein VP6 is reported. Patients described in this report were 10 years old or more and had mild to moderate clinical symptoms. A high nucleotide (>98%) and amino acid (100%) identity was observed among all three isolated Slovenian group C rotavirus strains. The similar identity is confirmed of Slovenian strains with other human group C rotavirus isolates, which were seen to cluster separately from the animal group C rotavirus isolates by a phylogenetic analysis. This is the first report of group C rotavirus detection in Slovenia.

Changing distribution of group A rotavirus G-types and genetic analysis of G9 circulating in Japan

A total of 1,797 fecal specimens from infants and children with acute gastroenteritis in Japan from July 2000 to June 2003 were tested for group A rotavirus by ELISA, RT-PCR, RNA-PAGE and latex agglutination methods. Of these, 439 were found to be positive for group A rotavirus and this presented 24.4%. In 2000-2001, G1 was the most prevalent (45.5%) followed by G2 (32.5%), G3 (12.3%), G9 (5.9%) and G4 (2.6%). However, G2 was found predominant with 40% in the following year (2001-2002). Interestingly, G9 had a rapid increase of infection up to 17.8%. In 2002-2003, G3 dominated over other G-types with 34%. Another interesting feature of the study was the demonstration of great genetic diversity among G9 strains in Japan. Worth of note was the first prevalence pattern of rotavirus G-types with an increase of G2, G3 as well as G9 and a decrease of G1 during the 20 year-survey of rotavirus infection in Japan.

Outbreaks of viral gastroenteritis: whatʼs new in 2004?

PURPOSE OF REVIEW

Descriptions of outbreaks of viral gastroenteritis have become a prominent feature in scientific journals and other media such as the electronic reporting service 'promed'. A review of outbreak reports was done to further our understanding of the burden of disease, common and rare modes of transmission, complications, and possibilities for control and prevention.

RECENT FINDINGS

Viral gastroenteritis outbreaks occur worldwide. In 2004, besides outbreak reports and surveys, there was considerable attention paid to food and waterborne outbreaks and the difficulties in proving these modes of transmission. Costs of viral gastroenteritis outbreaks are high. Complications and unusual manifestations of viral gastroenteritis, such as convulsions, transplant rejection, and chronic infection, may have been underreported.

SUMMARY

Viral gastroenteritis is a very common illness in health care settings that can cause significant disruption. Clinicians working in these settings should be familiar with the epidemiology and the possible modes of transmission of enteric viruses to be able to translate them into strategies for prevention or intervention. Research is needed to support these strategies.