Farm-to-fork investigation of an outbreak of Shiga toxin-producing Escherichia coli O157.

Fifteen cases of Shiga toxin-producing Escherichia coli (STEC) O157 infection were associated with the consumption of contaminated food from two related butchers' premises in the north-east of England. Ten cases were admitted to hospital and seven cases developed haemolytic uraemic syndrome. A case control study found a statistically significant association with the purchase of raw and/or ready-to-eat (RTE) food supplied by the implicated butchers' shops. Isolates of STEC O157 were detected in two raw lamb burgers taken from one of the butchers' premises. Subsequent environmental sampling identified STEC O157 in bovine faecal samples on the farm supplying cattle to the implicated butchers for slaughter. Whole genome sequencing (WGS) was performed on the Illumina HiSeq 2500 platform on all cultures isolated from humans, food and cattle during the investigation. Quality trimmed Illumina reads were mapped to the STEC O157 reference genome Sakai using bwa-mem, and single nucleotide polymorphisms (SNPs) were identified using gatk2. Analysis of the core genome SNP positions (>90 % consensus, minimum depth 10×, mapping quality (MQ)≥30) revealed that all isolates from humans, food and cattle differed by two SNPs. WGS analysis provided forensic-level microbiological evidence to support the epidemiological links between the farm, the butchers' premises and the clinical cases. Cross-contamination from raw meat to RTE foods at the butchers' premises was the most plausible transmission route. The evidence presented here highlights the importance of taking measures to mitigate the risks of cross-contamination in this setting.

Spatio-temporal models to determine association between Campylobacter cases and environment.

Background: Campylobacteriosis is a major cause of gastroenteritis in the UK, and although 70% of cases are associated with food sources, the remainder are probably associated with wider environmental exposure. Methods: In order to investigate wider environmental transmission, we conducted a spatio-temporal analysis of the association of human cases of Campylobacter in the Tyne catchment with weather, climate, hydrology and land use. A hydrological model was used to predict surface-water flow in the Tyne catchment over 5 years. We analysed associations between population-adjusted Campylobacter case rate and environmental factors hypothesized to be important in disease using a two-stage modelling framework. First, we investigated associations between temporal variation in case rate in relation to surface-water flow, temperature, evapotranspiration and rainfall, using linear mixed-effects models. Second, we used the random effects for the first model to quantify how spatial variation in static landscape features of soil and land use impacted on the likely differences between subcatchment associations of case rate with the temporal variables. Results: Population-adjusted Campylobacter case rates were associated with periods of high predicted surface-water flow, and during above average temperatures. Subcatchments with cattle on stagnogley soils, and to a lesser extent sheep plus cattle grazing, had higher Campylobacter case rates. Conclusions: Areas of stagnogley soils with mixed livestock grazing may be more vulnerable to both Campylobacter spread and exposure during periods of high rainfall, with resultant increased risk of human cases of the disease.

Increased Invasive Pneumococcal Disease, North East England, UK.

Since April 2014, invasive pneumococcal disease incidence has increased substantially across North East England, United Kingdom, reversing the decline that followed the 2006 introduction of pneumococcal conjugate vaccines. Significant increases occurred in 23-valent polysaccharide vaccine serotypes and nonvaccine serotypes. Trends in other regions and long-term effects of multivalent vaccines require further investigation.

Enforcement of science-using a Clostridium perfringens outbreak investigation to take legal action.

BACKGROUND: We report an outbreak of Clostridium perfringens in a care home in North East England. METHODS: A retrospective cohort study was used to investigate this outbreak. Faecal samples were obtained from symptomatic residents. Environmental Health Officers carried out a food hygiene inspection and formal statements were taken. RESULTS: Fifteen residents reported illness and the epidemic curve was suggestive of a point source outbreak. Results suggest that illness was associated with consumption of mince & vegetable pie and/or gravy. There were a number of issues with food served, in particular the mince products had been cooked, cooled, reheated and served again over a period of several days. Faecal sampling revealed the presence of C.perfringens enterotoxin gene and four samples were indistinguishable by fluorescent amplified fragment length polymorphism, indicating a likely common source. The operator of the home was charged with three offences under the General Food Regulations 2004 and the Food Hygiene (England) Regulations 2006 and was convicted on all counts. CONCLUSIONS: An outbreak of C.perfringens occurred in a care home. The likely cause was consumption of mince & vegetable pie and/or gravy. Epidemiological evidence can be used to help prosecute businesses with food safety offences in such circumstances.

An Outbreak of Cryptosporidium parvum across England & Scotland Associated with Consumption of Fresh Pre-Cut Salad Leaves, May 2012.

BACKGROUND: We report a widespread foodborne outbreak of Cryptosporidium parvum in England and Scotland in May 2012. Cases were more common in female adults, and had no history of foreign travel. Over 300 excess cases were identified during the period of the outbreak. Speciation and microbiological typing revealed the outbreak strain to be C. parvum gp60 subtype IIaA15G2R1. METHODS: Hypothesis generation questionnaires were administered and an unmatched case control study was undertaken to test the hypotheses raised. Cases and controls were interviewed by telephone. Controls were selected using sequential digit dialling. Information was gathered on demographics, foods consumed and retailers where foods were purchased. RESULTS: Seventy-four laboratory confirmed cases and 74 controls were included in analyses. Infection was found to be strongly associated with the consumption of pre-cut mixed salad leaves sold by a single retailer. This is the largest documented outbreak of cryptosporidiosis attributed to a food vehicle.

Accuracy of the interpretation of chest radiographs for the diagnosis of paediatric pneumonia.

INTRODUCTION: World Health Organization (WHO) radiological classification remains an important entry criterion in epidemiological studies of pneumonia in children. We report inter-observer variability in the interpretation of 169 chest radiographs in children suspected of having pneumonia. METHODS: An 18-month prospective aetiological study of pneumonia was undertaken in Northern England. Chest radiographs were performed on eligible children aged ≤16 years with clinical features of pneumonia. The initial radiology report was compared with a subsequent assessment by a consultant cardiothoracic radiologist. Chest radiographic changes were categorised according to the WHO classification. RESULTS: There was significant disagreement (22%) between the first and second reports (kappa = 0.70, P<0.001), notably in those aged <5 years (26%, kappa = 0.66, P<0.001). The most frequent sources of disagreement were the reporting of patchy and perihilar changes. CONCLUSION: This substantial inter-observer variability highlights the need for experts from different countries to create a consensus to review the radiological definition of pneumonia in children.

Emergence of pneumococcal 19A empyema in UK children.

INTRODUCTION: Invasive pneumococcal disease due to serotype 19A has become a major concern, particularly in the USA and Asia. We describe the characteristics of pneumococcal serotype 19A related empyema and changes in its incidence in the UK. METHODS: Data from paediatric empyema patients between September 2006 and March 2011 were collected from 17 respiratory centres in the UK. Pneumococcal serotypes were identified as part of the Health Protection Agency enhanced paediatric empyema surveillance programme. RESULTS: Four serotypes accounted for over 80% of 136 cases (Serotype 1 : 43%, 3 : 21%, 7 : 11% and 19A:10%). The incidence of empyema due to serotype 19A quadrupled from 0.48 (0.16-1.13) cases per million children in 2006/2007 to 2.02 (1.25-3.09) in 2010/2011. Severity of disease was significantly increased in children with 19A infection when compared to other serotypes. CONCLUSIONS: The incidence of empyema due to pneumococcal serotype 19A infection has increased significantly and is associated with substantial morbidity.

The re-emergence of syphilis in the United Kingdom: the new epidemic phases.

OBJECTIVE: The objective of this study was to characterize the resurgence of infectious syphilis in the United Kingdom between 1997 and 2003. STUDY: The authors conducted a retrospective analysis of routine surveillance data from genitourinary medicine clinics and data collected through enhanced surveillance. RESULTS: Between 1997 and 2002, diagnoses of primary, secondary, and early latent syphilis made at genitourinary medicine clinics increased by 213% in heterosexual males, 1412% in men who have sex with men (MSM), and 22% in females. These increases have been driven by a series of outbreaks, the largest of which were seen in Manchester (528) and London (1222) up to the end of October 2003. All the outbreaks have been geographically localized and the majority of cases occurred in MSM. A high percentage of concurrent HIV infection was reported, and oral sex was often reported as a route of transmission. CONCLUSIONS: Syphilis has re-emerged in response to behavior change, probably driven by changes in the HIV epidemic. The future course of the epidemic is difficult to predict and control remains elusive.