Predominance of enterovirus B and echovirus 30 as cause of viral meningitis in a UK population.

Background/objectives: Enteroviruses are the most common cause of aseptic or lymphocytic meningitis, particularly in children. With reports of unusually severe neurological disease in some patients infected with enterovirus D68 in North America, and a recent increase in the number of paediatric enterovirus meningitis cases presenting in this UK Midlands population, a retrospective regional surveillance study was performed.

Study Design: Cerebrospinal fluid (CSF) samples received were tested using the polymerase chain reaction (PCR) for HSV-1/2, VZV, enteroviruses and parechoviruses.

Tracking environmental norovirus contamination in a pediatric primary immunodeficiency unit.

Norovirus strains were detected in two patients and in environmental swabs from a pediatric primary immunodeficiency unit in London, United Kingdom, during an infection control incident in November and December 2007. Detailed analyses of the gene encoding the P2 domain demonstrated that the majority of the strains were not related to the patients and that the environmental contamination was most likely due to secondary transfer by the hands of staff or visitors.

Tracking the transmission routes of genogroup II noroviruses in suspected food-borne or environmental outbreaks of gastroenteritis through sequence analysis of the P2 domain.

The aim of this study was to apply sequence analysis of a hyper variable region of the norovirus (NoV) genome in order to identify point source outbreaks associated with suspect food or water. The hyper-variable region of the gene encoding the P2 domain was chosen as small differences in sequence are likely to indicate virus from different sources whereas identical sequence may reveal transmission routes and the source of contamination. Strains with 100% similarity were considered as originating from a common source, whereas, strains with one or more mutations in the hyper variable region sequenced were regarded as representing unrelated transmission events.

Food-related norovirus outbreak among people attending two barbeques: epidemiological, virological, and environmental investigation.

Background: Norovirus (NoV) is commonly associated with gastrointestinal infection. It is normally transmitted person-to-person or from contaminated surfaces, although food-borne transmission is possible.

Methods: We conducted environmental, epidemiological, and microbiological investigations to ascertain the route of transmission of two linked outbreaks of NoV associated with events where food was consumed.

Contamination of the hospital environment with gastroenteric viruses: comparison of two pediatric wards over a winter season.

The aims of this study were to examine the extent of gastroenteric virus contamination in a pediatric primary immunodeficiency (PPI) ward and a general pediatric ward over a winter season and to determine whether changes to hospital infection control interventions would have an impact on environmental contamination levels within pediatric units. Environmental swabs were collected weekly from 11 sites in both wards from 15 December 2005 to 3 March 2006 and examined for the presence of norovirus (NoV), astrovirus, and rotavirus (RV) by reverse transcriptase PCR. Viruses were detected in 17% and 19% of swabs from both wards.

Analysis of amino acid variation in the P2 domain of the GII-4 norovirus VP1 protein reveals putative variant-specific epitopes.

Background: Human noroviruses are a highly diverse group of viruses classified into three of the five currently recognised Norovirus genogroups, and contain numerous genotypes or genetic clusters. Noroviruses are the major aetiological agent of endemic gastroenteritis in all age groups, as well as the cause of periodic epidemic gastroenteritis. The noroviruses most commonly associated with outbreaks of gastroenteritis are genogroup II genotype 4 (GII-4) strains.

European multicenter evaluation of commercial enzyme immunoassays for detecting norovirus antigen in fecal samples.

A total of 2,254 fecal samples were tested in a European multicenter evaluation of commercially available norovirus antigen detection assays. Two commercial enzyme immunoassays, IDEIA Norovirus (Oxoid; Thermo Fisher Scientific, Ely, United Kingdom) and RIDASCREEN Norovirus (R-Biopharm, Darmstadt, Germany), were included in the evaluation, and their performance was compared with the results of reverse transcription-PCR (RT-PCR). Included in the evaluation were samples collected in sporadic cases of gastroenteritis, samples from outbreaks in which two or more samples were collected, well-characterized samples representing genotypes currently cocirculating within Europe, and samples collected from patients with gastroenteritis caused by a pathogen other than norovirus.

Characterization of sapoviruses collected in the United Kingdom from 1989 to 2004.

A fecal archive containing 115 sapovirus (SaV) strains detected in samples collected from 15 outbreaks and 98 sporadic cases of gastroenteritis between 1989 and 2004 in the UK were characterized in order to determine the genomic diversity within SaV co-circulating in the human population. Strains were characterized by partial sequencing of the genes encoding the RNA-dependent RNA polymerase (RdRp) region and/or the polymerase/capsid (Pol/Cap) junction of the open reading frame (Orf) 1. Overall, SaV of genogroup I genotype 1 (GI 1) were the predominant strains circulating in the UK in each year between 1989 and 2004.

Environmental monitoring for gastroenteric viruses in a pediatric primary immunodeficiency unit.

The aim of this study was to determine if gastroenteric viruses were present on surfaces and equipment in a pediatric primary immunodeficiency unit (PPIU) by environmental sampling using swabs and subsequent nucleic acid extraction and reverse transcriptase PCR assays. A PPIU was chosen, and 11 swabs were taken at the same sites every 2 weeks for 6 months. Nested/heminested PCR assays were used to screen for astroviruses (AsV), noroviruses (NoV), and rotaviruses (RV).

Gastroenteritis outbreak in British troops, Iraq.

Gastroenteritis affected many British military personnel during the war in Iraq. In the first month, 1,340 cases were seen; 73% of patients required hospital admission and 36% were hospital staff. In a survey of 500 hospital staff, 76% reported gastroenteritis, which was more likely in clinical workers.

Use of a heminested reverse transcriptase PCR assay for detection of astrovirus in environmental swabs from an outbreak of gastroenteritis in a pediatric primary immunodeficiency unit.

An outbreak of astrovirus gastroenteritis occurred in the Primary Immunodeficiency Unit at Newcastle General Hospital in March 2004. Environmental swabbing of the unit was undertaken after the outbreak, with multiple sites swabbed pre- and postcleaning. Astroviruses were detected in four environmental swabs and from two patient fecal samples using heminested reverse transcriptase PCR.

Multiple norovirus genotypes characterised from an oyster-associated outbreak of gastroenteritis.

The diversity of norovirus (NV) genotypes was investigated in persons who were ill with acute gastroenteritis associated with the consumption of oysters. Initial results from a commercial enzyme immunoassay (EIA) indicated a mixed NV genogroup I (GI) and II (GII) outbreak. A reverse-transcriptase (RT)-PCR for NVs was applied to nucleic acid extracted from faecal specimens collected from symptomatic cases.

Application of the heteroduplex mobility assay (HMA) for the investigation of the genomic diversity among noroviruses in environmental samples.

Recent studies have demonstrated the widespread contamination of river and seawater with noroviruses (NV), often with more than one strain. The heteroduplex mobility assay (HMA) in which amplicons from study samples are hybridised (by denaturing and reannealing) to amplicons from reference strains and resolved by electrophoresis, has the potential to provide a simple and rapid means to identify samples containing multiple NV strains and to establish the diversity of strains within that sample. PCR amplicons from environmental samples that were tested directly in the HMA assay were shown to contain more than one strain.

Diversity of enteric viruses detected in patients with gastroenteritis in a tertiary referral paediatric hospital.

The genetic diversity of enteric viruses co-circulating in a cohort of patients with viral gastroenteritis in a large tertiary paediatric hospital in London, UK, was determined. Multiple strains of noroviruses (NV), sapoviruses (SV) and astroviruses (HAsV) were detected in these patients, indicating the likelihood of multiple introductions from different sources, possible sub-clinical infections and simultaneous infection with different viruses in immunocompromised and other patients. Routine screening of immunocompromised patients and infection control procedures are important to prevent nosocomial infection.

Asymptomatic and symptomatic excretion of noroviruses during a hospital outbreak of gastroenteritis.

During an investigation of a hospital outbreak of norovirus gastroenteritis identified as being caused by a recombinant genogroup II (rGII-3a) strain, fecal specimens collected from asymptomatic staff and patients were tested by nested PCR. A GII-4 norovirus strain, the predominant strain associated with outbreaks in hospitals over the last few years, was detected in 26 and 33% of asymptomatic staff and patients, respectively. No rGII-3a (Harrow/Mexico) norovirus strains were detected in the samples of asymptomatic staff or patients.

Methods for the detection and characterisation of noroviruses associated with outbreaks of gastroenteritis: outbreaks occurring in the north-west of England during two norovirus seasons.

This article describes the methods used to investigate 407 outbreaks of acute non-bacterial gastroenteritis occurring in the North-West of England between January 2000 and July 2001 and suspected to be caused by noroviruses (NV) [Mayo (2002) Arch Virol 147:1655-1663]. These included 319 outbreaks in hospitals and nursing homes and 88 other settings. Eight hundred and seventy-one faecal samples from 407 outbreaks were tested using electron microscopy (EM), an enzyme-linked immunosorbent assay (ELISA) specific for Grimsby virus (GRV) capsid antigen and/or by reverse transcriptase-polymerase chain reaction (RT-PCR) for NV, allowing the utility of each assay for routine diagnosis to be assessed.

Diversity of noroviruses cocirculating in the north of England from 1998 to 2001.

A study was undertaken to investigate the diversity of noroviruses (NVs) in fecal samples from patients from 529 outbreaks and 141 sporadic cases of gastroenteritis in the North of England from September 1998 to August 2001. NV strains were detected by electron microscopy and characterized by a combination of the Grimsby virus antigen enzyme-linked immunosorbent assay, reverse transcriptase PCR, the heteroduplex mobility assay, and DNA sequencing. Twenty-one distinct NV strains, including several novel or variant strains not seen previously, were found circulating in the population studied.

Quantitation of group A rotavirus by real-time reverse-transcription-polymerase chain reaction: correlation with clinical severity in children in South India.

The epidemiology and pathogenesis of rotaviruses are not completely understood, although recent developments in polymerase chain reaction (PCR) techniques now make it possible to quantify the viral load during an infective episode and investigate its relevance to clinical features of the disease. We studied rotavirus-positive stool samples collected from 10 children without symptoms of gastroenteritis and from 81 children with acute gastroenteritis and in whom the clinical severity of disease was recorded. A semi-quantitative real-time reverse-transcription (RT)-PCR was used to estimate the rotavirus load and to assess its correlation with the Vesikari score for severity of diarrhoea.