Acceptability of temporary suspension of visiting during norovirus outbreaks:investigating patient, visitor and public opinion

Background Noroviruses are a leading cause of outbreaks globally and the most common cause of service disruption due to ward closures. Temporary suspension of visiting (TSV) is increasingly a recommended public health measure to reduce exposure, transmission and impact during norovirus outbreaks; however, preventing patient–visitor contact may contravene the ethos of person-centred care, and public acceptability of this measure is not known. Aim To investigate the acceptability of TSV during norovirus outbreaks from the perspectives of patients, visitors and the wider public. Methods Cross-sectional survey of patients (N = 153), visitors (N = 175) and the public (N = 224) in three diverse areas in Scotland. Health Belief Model constructs were applied to understand ratings of acceptability of TSV during norovirus outbreaks, and to determine associations between these levels and various predictor variables. Findings The majority (84.6%) of respondents indicated that the possible benefits of TSV are greater than the possible disadvantages. Conversely, the majority (70%) of respondents disagreed that TSV ‘is wrong as it ignores people's rights to have contact with family and friends’. The majority (81.6%) of respondents agreed that TSV would be more acceptable if exceptions were made for seriously ill or dying patients. Correlational analysis demonstrated that overall acceptability was positively related to perceived severity (r = 0.65), identified benefits (r = 0.54) and implementing additional communication strategies (r = 0.60); acceptability was negatively related to potential barriers (r = −0.49). Conclusions There is greater service user and public support for the use of TSV than concerns around impinging upon patients' rights to have visitors. TSV should be considered as an acceptable infection control measure that could be implemented consistently during norovirus outbreaks

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. Enterovirus PCR positive CSF samples were sent for further serotyping. A phylogenetic tree was constructed of the echovirus 30 VP1 sequences, where sufficient sample remained for sequencing. RESULTS: The number of enterovirus positive CSFs from each year were: 21 (2008), 7 (2011), 53 (2012), 58 (2013) and 31 (2014). Overall, 163 of the 170 serotyped enteroviruses belonged to the species B (echovirus 5, 6, 7, 9, 11, 13, 16, 17, 18, 21, 25, 30; coxsackie B1, B2, B3, B4, B5, A9), with only 7 belonging to species A (coxsackie A2, A6, A16 and enterovirus 71). Echovirus 30 was the predominant serotype overall, identified in 43 (25.3%) of samples, with a significantly higher proportion in the adult age group (37.3%) compared to the infant age group (12.3%). Phylogenetic analysis showed that these UK Midlands echovirus 30 VP1 sequences clustered most closely with those from Europe and China. CONCLUSION: This study showed a continued predominance of echovirus 30 as a cause of viral meningitis, particularly in adults, though more surveillance is needed

Foodborne norovirus outbreak: the role of an asymptomatic food handler

Background: In July 2005 an outbreak of acute gastroenteritis occurred on a residential summer camp in the province of Barcelona (northeast of Spain). Forty-four people were affected among residents and employees. All of them had in common a meal at lunch time on 13 July (paella, round of beef and fruit). The aim of this study was to investigate a foodborne norovirus outbreak that occurred in the residential summer camp and in which the implication of a food handler was demonstrated by laboratory tests. Methods: A retrospective cohort study was designed. Personal or telephone interview was carried out to collect demographic, clinical and microbiological data of the exposed people, as well as food consumption in the suspected lunch. Food handlers of the mentioned summer camp were interviewed. Ten stool samples were requested from symptomatic exposed residents and the three food handlers that prepared the suspected food. Stools were tested for bacteries and noroviruses. Norovirus was detected using RT-PCR and sequence analysis. Attack rate, relative risks (RR) and its 95% confidence intervals (CI) were calculated to assess the association between food consumption and disease. Results: The global attack rate of the outbreak was 55%. The main symptoms were abdominal pain (90%), nausea (85%), vomiting (70%) and diarrhoea (42.5%). The disease remitted in 24-48 hours. Norovirus was detected in seven faecal samples, one of them was from an asymptomatic food handler who had not eaten the suspected food (round of beef), but cooked and served the lunch. Analysis of the two suspected foods isolated no pathogenic bacteria and detected no viruses. Molecular analysis showed that the viral strain was the same in ill patients and in the asymptomatic food handler (genotype GII.2 Melksham-like). Conclusions: In outbreaks of foodborne disease, the search for viruses in affected patients and all food handlers, even in those that are asymptomatic, is essential. Health education of food handlers with respect to hand washing should be promoted

Selection of a phylogenetically informative region of the norovirus genome for outbreak linkage

The recognition of a common source norovirus outbreak is supported by finding identical norovirus sequences in patients. Norovirus sequencing has been established in many (national) public health laboratories and academic centers, but often partial and different genome sequences are used. Therefore, agreement on a target sequence of sufficient diversity to resolve links between outbreaks is crucial. Although harmonization of laboratory methods is one of the keystone activities of networks that have the aim to identify common source norovirus outbreaks, this has proven difficult to accomplish, particularly in the international context. Here, we aimed at providing a method enabling identification of the genomic region informative of a common source norovirus outbreak by bio-informatic tools. The data set of 502 unique full length capsid gene sequences available from the public domain, combined with epidemiological data including linkage information was used to build over 3,000 maximum likelihood (ML) trees for different sequence lengths and regions. All ML trees were evaluated for robustness and specificity of clustering of known linked norovirus outbreaks against the background diversity of strains. Great differences were seen in the robustness of commonly used PCR targets for cluster detection. The capsid gene region spanning nucleotides 900–1,400 was identified as the region optimally substituting for the full length capsid region. Reliability of this approach depends on the quality of the background data set, and we recommend periodic reassessment of this growing data set. The approach may be applicable to multiple sequence-based data sets of other pathogens

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. This study was able to identify a point source outbreak of a dominant strain, GII-4, on a cruise ship but also of a less common strain, GII-2, between two schools. Also identical GII-3 strains were demonstrated in food handlers amongst the same outbreak; however epidemiologically related outbreaks showed different GII-3 strains indicating multiple sources of contamination

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

Genetic Characterization of Genogroup I Norovirus in Outbreaks of Gastroenteritis

In this study, we demonstrate that differences within the P2 domain of norovirus genogroup I (GI) strains can be used to segregate outbreaks which are unrelated, whereas complete conservation within this region allows tracking of strains that are part of a single outbreak and likely to have a common source

Evaluation of the Loopamp (loop-mediated isothermal amplification) kit for detecting Norovirus RNA in faecal samples

The Loopamp GII detection kit is a sensitive method for detecting all the commonly circulating GII-4 strains included in the evaluation panel