Natalie L. Adams

Emergence of the GII-4 Norovirus Sydney2012 strain in England, winter 2012-2013.

Norovirus is the commonest cause of acute gastrointestinal disease and is the main aetiological agent of outbreaks of gastroenteritis, particularly in semi-closed environments. Norovirus infections in England typically peak between December and March each year. The most commonly detected norovirus strains belong to the genetically diverse genogroup-II genotype-4 (GII-4) genocluster and in the previous two norovirus winter seasons the majority of GII-4 strains in circulation worldwide have been genetically similar to the GII-4 strain New Orleans 1805/2009/USA. At the beginning of the 2012/13 season a genetically distinct GII-4 strain (Sydney 2012/NSW0514/2012/AU) was described which emerged worldwide during the winter of 2012/13. Here we describe the emergence of norovirus strains genetically related to Sydney2012 in England during the 2012/13 season to replace NewOrleans2009 strains as the most commonly detected variant of GII-4 norovirus in England. Furthermore, we demonstrate that whilst the emergence of Sydney2012 coincided with an early peak in the number of norovirus outbreaks, there was not an overall increase in norovirus activity compared to the previous season. Finally, we show that the Sydney2012 strain is associated with distinct genetic changes compared to the NewOrleans2009 strain, and these changes may have contributed to the emergence of the Sydney2012 strain.

Shiga Toxin–Producing Escherichia coli O157, England and Wales, 1983–2012

Although incidence remained constant, outbreaks from contaminated meat and milk declined and those from petting farms and schools and nurseries increased.

Salmonella enterica Serovar Enteritidis, England and Wales, 1945–2011

A focus on eliminating phage type 4 in egg and poultry production has greatly reduced foodborne disease among humans.

Epidemiological and Microbiological Investigation of an Outbreak of Severe Disease from Shiga Toxin–Producing Escherichia coli O157 Infection Associated with Consumption of a Slaw Garnish

Investigating outbreaks of Shiga toxin-producing Escherichia coli (STEC) in England is a priority due to the potential severity of disease. However, there are often challenges in investigating outbreaks due to the small numbers of cases, poor patient recall, and low levels of bacteria that are challenging to detect in food samples using traditional laboratory culture techniques, and frequently a source is not identified. In September 2014, we investigated an STEC O157 outbreak associated with consuming a slaw garnish, and we report our findings here. Twenty confirmed cases were identified. Outbreak cases were interviewed, and menus reviewed to identify dishes consumed outside the home. Cases shared a history of eating meals at different chain restaurants. Analysis of menu items indicated shared consumption of slaw garnishes by 85.6% cases, although just 35.7% reported consuming them during interviews. Whole-genome sequencing linked cases where interpretation of the multilocus variable number tandem repeat analysis profile was obscured and indicated that the strain originated from a domestic (i.e., United Kingdom) source. Traceback identified that carrots and cabbages grown in the United Kingdom were the likely source of infection. Samples of products were examined, but STEC was not recovered. Epidemiological investigations linked the outbreak to consumption of a slaw garnish, which was poorly recalled by cases, and likely comprised of domestically produced raw vegetables. The causative organism was not isolated from food samples, and we conclude that future investigations should include sampling of animals and wildlife in the vicinity of farms where implicated produce is grown.

Relationship between socioeconomic status and gastrointestinal infections in developed countries: A systematic review protocol

BackgroundThe association between low socioeconomic status (SES) and poor health is well documented in the existing literature. Nonetheless, evidence on the relationship between SES and gastrointestinal (GI) infections is limited, and the mechanisms underlying this relationship are not well understood with published studies pointing to conflicting results. This review aims to identify studies that investigate the relationship between SES and GI infections in developed countries, in order to assess the direction of the association and explore possible explanations for any differences in the risk, incidence or prevalence of GI infections across socioeconomic groups.MethodsThree systematic methods will be used to identify relevant literature: electronic database, reference list and grey literature searching. The databases MEDLINE, Scopus and Web of Science Core Collection will be searched using a broad range of search terms. Screening of the results will be performed by two reviewers using pre-defined inclusion and exclusion criteria. The reference lists of included studies will be searched, and Google will be used to identify grey literature. Observational studies reporting quantitative results on the prevalence or incidence of any symptomatic GI infections by SES, in a representative population sample from a member country of the Organisation for Economic Co-operation and Development (OECD), will be included. Data will be extracted using a standardised form. Study quality will be assessed using the Liverpool University Quality Assessment Tools (LQAT). A narrative synthesis will be performed including tabulation of studies for comparison.DiscussionThis systematic review will consolidate the existing knowledge on the relationship between SES and GI infections. The results will help to identify gaps in the literature and will therefore provide an evidence base for future empirical studies to deepen the understanding of the relationship, including effective study design and appropriate data analysis methods. Ultimately, gaining insight into this relationship will help to inform policies to reduce any health inequalities identified.Systematic review registrationPROSPERO CRD42015027231

Socioeconomic status and infectious intestinal disease in the community: a longitudinal study (IID2 Study)

Abstract Background Infectious intestinal diseases (IID) are common, affecting around 25% of people in UK each year at an estimated annual cost to the economy, individuals and the NHS of £1.5 billion. While there is evidence of higher IID hospital admissions in more disadvantaged groups, the association between socioeconomic status (SES) and risk of IID remains unclear. This study aims to investigate the relationship between SES and IID in a large community cohort. Methods Longitudinal analysis of a prospective community cohort in the UK following 6836 participants of all ages was undertaken. Hazard ratios for IID by SES were estimated using Cox proportional hazard, adjusting for follow-up time and potential confounding factors. Results In the fully adjusted analysis, hazard ratio of IID was significantly lower among routine/manual occupations compared with managerial/professional occupations (HR 0.74, 95% CI 0.61–0.90). Conclusion In this large community cohort, lower SES was associated with lower IID risk. This may be partially explained by the low response rate which varied by SES. However, it may be related to differences in exposure or recognition of IID symptoms by SES. Higher hospital admissions associated with lower SES observed in some studies could relate to more severe consequences, rather than increased infection risk.

Social patterning of telephone health-advice for diarrhoea and vomiting: analysis of 24 million telehealth calls in England

Highlights • Disadvantaged areas were associated with higher risk of gastrointestinal infection (GI) calls to the National Health Service (NHS) telephone advice services in England.• This trend was seen across age groups.• This may reflect differential exposure or vulnerability to GI infections by socioeconomic status.• It may also reflect differential propensity to call about GI infections by socioeconomic status.

Socioeconomic status is associated with symptom severity and sickness absence in people with infectious intestinal disease in the UK

BackgroundThe burden of infectious intestinal disease (IID) in the UK is substantial. Negative consequences including sickness absence are common, but little is known about the social patterning of these outcomes, or the extent to which they relate to disease severity.MethodsWe performed a cross-sectional analysis using IID cases identified from a large population-based survey, to explore the association between socioeconomic status (SES) and symptom severity and sickness absence; and to assess the role of symptom severity on the relationship between SES and absence. Regression modelling was used to investigate these associations, whilst controlling for potential confounders such as age, sex and ethnicity.ResultsAmong 1164 cases, those of lower SES versus high had twice the odds of experiencing severe symptoms (OR 2.2, 95%CI;1.66–2.87). Lower SES was associated with higher odds of sickness absence (OR 1.8, 95%CI;1.26–2.69), however this association was attenuated after adjusting for symptom severity (OR 1.4, 95%CI;0.92–2.07).ConclusionsIn a large sample of IID cases, those of low SES versus high were more likely to report severe symptoms, and sickness absence; with greater severity largely explaining the higher absence. Public health interventions are needed to address the unequal consequences of IID identified.