Investigation of the impact of the NICE guidelines regarding antibiotic prophylaxis during invasive dental procedures on the incidence of infective endocarditis in England: an electronic health records study.

BACKGROUND: Infective endocarditis is an uncommon but serious infection, where evidence for giving antibiotic prophylaxis before invasive dental procedures is inconclusive. In England, antibiotic prophylaxis was offered routinely to patients at risk of infective endocarditis until March 2008, when new guidelines aimed at reducing unnecessary antibiotic use were issued. We investigated whether changes in infective endocarditis incidence could be detected using electronic health records, assessing the impact of inclusion criteria/statistical model choice on inferences about the timing/type of any change. METHODS: Using national data from Hospital Episode Statistics covering 1998-2017, we modelled trends in infective endocarditis incidence using three different sets of inclusion criteria plus a range of regression models, identifying the most likely date for a change in trends if evidence for one existed. We also modelled trends in the proportions of different organism groups identified during infection episodes, using secondary diagnosis codes and data from national laboratory records. Lastly, we applied non-parametric local smoothing to visually inspect any changes in trend around the guideline change date. RESULTS: Infective endocarditis incidence increased markedly over the study (22.2-41.3 per million population in 1998 to 42.0-67.7 in 2017 depending on inclusion criteria). The most likely dates for a change in incidence trends ranged from September 2001 (uncertainty interval August 2000-May 2003) to May 2015 (March 1999-January 2016), depending on inclusion criteria and statistical model used. For the proportion of infective endocarditis cases associated with streptococci, the most likely change points ranged from October 2008 (March 2006-April 2010) to August 2015 (September 2013-November 2015), with those associated with oral streptococci decreasing in proportion after the change point. Smoothed trends showed no notable changes in trend around the guideline date. CONCLUSIONS: Infective endocarditis incidence has increased rapidly in England, though we did not detect any change in trends directly following the updated guidelines for antibiotic prophylaxis, either overall or in cases associated with oral streptococci. Estimates of when changes occurred were sensitive to inclusion criteria and statistical model choice, demonstrating the need for caution in interpreting single models when using large datasets. More research is needed to explore the factors behind this increase.

The Impact of a National Antimicrobial Stewardship Program on Antibiotic Prescribing in Primary Care: An Interrupted Time Series Analysis.

BACKGROUND: The Quality Premium was introduced in 2015 to financially reward local commissioners of healthcare in England for targeted reductions in antibiotic prescribing in primary care. METHODS: We used a national antibiotic prescribing dataset from April 2013 until February 2017 to examine the number of antibiotic items prescribed, the total number of antibiotic items prescribed per STAR-PU (specific therapeutic group age/sex-related prescribing units), the number of broad-spectrum antibiotic items prescribed, and broad-spectrum antibiotic items prescribed, expressed as a percentage of the total number of antibiotic items. To evaluate the impact of the Quality Premium on antibiotic prescribing, we used a segmented regression analysis of interrupted time series data. RESULTS: During the study period, over 140 million antibiotic items were prescribed in primary care. Following the introduction of the Quality Premium, antibiotic items prescribed decreased by 8.2%, representing 5933563 fewer antibiotic items prescribed during the 23 post-intervention months, as compared with the expected numbers based on the trend in the pre-intervention period. After adjusting for the age and sex distribution in the population, the segmented regression model also showed a significant relative decrease in antibiotic items prescribed per STAR-PU. A similar effect was found for broad-spectrum antibiotics (comprising 10.1% of total antibiotic prescribing), with an 18.9% reduction in prescribing. CONCLUSIONS: This study shows that the introduction of financial incentives for local commissioners of healthcare to improve the quality of prescribing was associated with a significant reduction in both total and broad-spectrum antibiotic prescribing in primary care in England.

An Assessment of Potential Unintended Consequences Following a National Antimicrobial Stewardship Program in England: An Interrupted Time Series Analysis.

BACKGROUND: The "Quality Premium" (QP) introduced in England in 2015 aimed to financially reward local healthcare commissioners for targeted reductions in primary care antibiotic prescribing. We aimed to evaluate possible unintended clinical outcomes related to this QP. METHODS: Using Clinical Practice Research Datalink and Hospital Episode Statistics datasets, we examined general practitioner (GP) consultations (visits) and emergency hospital admissions related to a series of predefined conditions of unintended consequences of reduced prescribing. Monthly age- and sex-standardized rates were calculated using a direct method of standardization. We used segmented regression analysis of interrupted time series to evaluate the impact of the QP on seasonally adjusted outcome rates. RESULTS: We identified 27334 GP consultations and >5 million emergency hospital admissions with predefined conditions. There was no evidence that the QP was associated with changes in GP consultation and hospital admission rates for the selected conditions combined. However, when each condition was considered separately, a significant increase in hospital admission rates was noted for quinsy, and significant decreases were seen for hospital-acquired pneumonia, scarlet fever, pyelonephritis, and complicated urinary tract conditions. A significant decrease in GP consultation rates was estimated for empyema and scarlet fever. No significant changes were observed for other conditions. CONCLUSIONS: Findings from this study show that overall there was no significant association between the intervention and unintended clinical consequences, with the exception of a few specific conditions, most of which could be explained through other parallel policy changes or should be interpreted with caution due to small numbers.

'Caveat emptor': the cautionary tale of endocarditis and the potential pitfalls of clinical coding data-an electronic health records study.

BACKGROUND: Diagnostic codes from electronic health records are widely used to assess patterns of disease. Infective endocarditis is an uncommon but serious infection, with objective diagnostic criteria. Electronic health records have been used to explore the impact of changing guidance on antibiotic prophylaxis for dental procedures on incidence, but limited data on the accuracy of the diagnostic codes exists. Endocarditis was used as a clinically relevant case study to investigate the relationship between clinical cases and diagnostic codes, to understand discrepancies and to improve design of future studies. METHODS: Electronic health record data from two UK tertiary care centres were linked with data from a prospectively collected clinical endocarditis service database (Leeds Teaching Hospital) or retrospective clinical audit and microbiology laboratory blood culture results (Oxford University Hospitals Trust). The relationship between diagnostic codes for endocarditis and confirmed clinical cases according to the objective Duke criteria was assessed, and impact on estimations of disease incidence and trends. RESULTS: In Leeds 2006-2016, 738/1681(44%) admissions containing any endocarditis code represented a definite/possible case, whilst 263/1001(24%) definite/possible endocarditis cases had no endocarditis code assigned. In Oxford 2010-2016, 307/552(56%) reviewed endocarditis-coded admissions represented a clinical case. Diagnostic codes used by most endocarditis studies had good positive predictive value (PPV) but low sensitivity (e.g. I33-primary 82% and 43% respectively); one (I38-secondary) had PPV under 6%. Estimating endocarditis incidence using raw admission data overestimated incidence trends twofold. Removing records with non-specific codes, very short stays and readmissions improved predictive ability. Estimating incidence of streptococcal endocarditis using secondary codes also overestimated increases in incidence over time. Reasons for discrepancies included changes in coding behaviour over time, and coding guidance allowing assignment of a code mentioning 'endocarditis' where endocarditis was never mentioned in the clinical notes. CONCLUSIONS: Commonly used diagnostic codes in studies of endocarditis had good predictive ability. Other apparently plausible codes were poorly predictive. Use of diagnostic codes without examining sensitivity and predictive ability can give inaccurate estimations of incidence and trends. Similar considerations may apply to other diseases. Health record studies require validation of diagnostic codes and careful data curation to minimise risk of serious errors.

Epidemiology and Outcomes of Nontyphoidal Salmonella Bacteremias from England, 2004 to 2015.

Nontyphoidal Salmonella (NTS) bacteremia causes hospitalization and high morbidity and mortality. We linked Gastrointestinal Bacteria Reference Unit (GBRU) data to the Hospital Episode Statistics (HES) data set to study the trends and outcomes of NTS bacteremias in England between 2004 and 2015. All confirmed NTS isolates from blood from England submitted to GBRU between 1 January 2004 and 31 December 2015 were deterministically linked to HES records. Adjusted odds ratios (AOR), proportions, and confidence intervals (CI) were calculated to describe differences in age, sex, antibiotic resistance patterns, and serotypes over time. Males, neonates, and adults above 65 years were more likely to have NTS bacteremia (AOR, 1.54 [95% CI, 1.46 to 1.67]; 2.57 [95% CI, 1.43 to 4.60]; and 3.56 [95% CI, 3.25 to 3.90], respectively). Proportions of bacteremia increased from 1.41% in 2004 to 2.67% in 2015. Thirty-four percent of all blood isolates were resistant to a first-line antibiotic, and 1,397 (56%) blood isolates were linked to an HES record. Of the patients with NTS bacteremia, 969 (69%) had a cardiovascular condition and 155 (12%) patients died, out of which 120 (77%) patients were age 65 years and above. NTS bacteremia mainly affects older people with comorbidities placing them at increased risk of prolonged hospital stay and death. Resistance of invasive NTS to first-line antimicrobial agents appeared to be stable in England, but the emergence of resistance to last-resort antibiotics, such as colistin, requires careful monitoring.

Strong correlation between the rates of intrinsically antibiotic-resistant species and the rates of acquired resistance in Gram-negative species causing bacteraemia, EU/EEA, 2016.

BackgroundAntibiotic resistance, either intrinsic or acquired, is a major obstacle for treating bacterial infections.AimOur objective was to compare the country-specific species distribution of the four Gram-negative species Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter species and the proportions of selected acquired resistance traits within these species.MethodWe used data reported for 2016 to the European Antimicrobial Resistance Surveillance Network (EARS-Net) by 30 countries in the European Union and European Economic Area.ResultsThe country-specific species distribution varied considerably. While E. coli accounted for 31.9% to 81.0% (median: 69.0%) of all reported isolates, the two most common intrinsically resistant species P. aeruginosa and Acinetobacter spp. combined (PSEACI) accounted for 5.5% to 39.2% of isolates (median: 10.1%). Similarly, large national differences were noted for the percentages of acquired non-susceptibility to third-generation cephalosporins, carbapenems and fluoroquinolones. There was a strong positive rank correlation between the country-specific percentages of PSEACI and the percentages of non-susceptibility to the above antibiotics in all four species (rho > 0.75 for 10 of the 11 pairs of variables tested).ConclusionCountries with the highest proportion of P. aeruginosa and Acinetobacter spp. were also those where the rates of acquired non-susceptibility in all four studied species were highest. The differences are probably related to national differences in antibiotic consumption and infection prevention and control routines.

Quantifying where human acquisition of antibiotic resistance occurs: a mathematical modelling study.

BACKGROUND: Antibiotic-resistant bacteria (ARB) are selected by the use of antibiotics. The rational design of interventions to reduce levels of antibiotic resistance requires a greater understanding of how and where ARB are acquired. Our aim was to determine whether acquisition of ARB occurs more often in the community or hospital setting. METHODS: We used a mathematical model of the natural history of ARB to estimate how many ARB were acquired in each of these two environments, as well as to determine key parameters for further investigation. To do this, we explored a range of realistic parameter combinations and considered a case study of parameters for an important subset of resistant strains in England. RESULTS: If we consider all people with ARB in the total population (community and hospital), the majority, under most clinically derived parameter combinations, acquired their resistance in the community, despite higher levels of antibiotic use and transmission of ARB in the hospital. However, if we focus on just the hospital population, under most parameter combinations a greater proportion of this population acquired ARB in the hospital. CONCLUSIONS: It is likely that the majority of ARB are being acquired in the community, suggesting that efforts to reduce overall ARB carriage should focus on reducing antibiotic usage and transmission in the community setting. However, our framework highlights the need for better pathogen-specific data on antibiotic exposure, ARB clearance and transmission parameters, as well as the link between carriage of ARB and health impact. This is important to determine whether interventions should target total ARB carriage or hospital-acquired ARB carriage, as the latter often dominated in hospital populations.

Age-related decline in antibiotic prescribing for uncomplicated respiratory tract infections in primary care in England following the introduction of a national financial incentive (the Quality Premium) for health commissioners to reduce use of antibiotics in the community: an interrupted time series analysis.

Objectives: To assess the impact of the 2015/16 NHS England Quality Premium (which provided a financial incentive for Clinical Commissioning Groups to reduce antibiotic prescribing in primary care) on antibiotic prescribing by General Practitioners (GPs) for respiratory tract infections (RTIs). Methods: Interrupted time series analysis using monthly patient-level consultation and prescribing data obtained from the Clinical Practice Research Datalink (CPRD) between April 2011 and March 2017. The study population comprised patients consulting a GP who were diagnosed with an RTI. We assessed the rate of antibiotic prescribing in patients (both aggregate and stratified by age) with a recorded diagnosis of uncomplicated RTI, before and after the implementation of the Quality Premium. Results: Prescribing rates decreased over the 6 year study period, with evident seasonality. Notably, there was a 3% drop in the rate of antibiotic prescribing (equating to 14.65 prescriptions per 1000 RTI consultations) (P < 0.05) in April 2015, coinciding with the introduction of the Quality Premium. This reduction was sustained, such that after 2 years there was a 3% decrease in prescribing relative to that expected had the pre-intervention trend continued. There was also a concurrent 2% relative reduction in the rate of broad-spectrum antibiotic prescribing. Antibiotic prescribing for RTIs diagnosed in children showed the greatest decline with a 6% relative change 2 years after the intervention. Of the RTI indications studied, the greatest reductions in antibiotic prescribing were seen for patients with sore throats. Conclusions: Community prescribing of antibiotics for RTIs significantly decreased following the introduction of the Quality Premium, with the greatest reduction seen in younger patients.

Measuring distance through dense weighted networks: The case of hospital-associated pathogens.

Hospital networks, formed by patients visiting multiple hospitals, affect the spread of hospital-associated infections, resulting in differences in risks for hospitals depending on their network position. These networks are increasingly used to inform strategies to prevent and control the spread of hospital-associated pathogens. However, many studies only consider patients that are received directly from the initial hospital, without considering the effect of indirect trajectories through the network. We determine the optimal way to measure the distance between hospitals within the network, by reconstructing the English hospital network based on shared patients in 2014-2015, and simulating the spread of a hospital-associated pathogen between hospitals, taking into consideration that each intermediate hospital conveys a delay in the further spread of the pathogen. While the risk of transferring a hospital-associated pathogen between directly neighbouring hospitals is a direct reflection of the number of shared patients, the distance between two hospitals far-away in the network is determined largely by the number of intermediate hospitals in the network. Because the network is dense, most long distance transmission chains in fact involve only few intermediate steps, spreading along the many weak links. The dense connectivity of hospital networks, together with a strong regional structure, causes hospital-associated pathogens to spread from the initial outbreak in a two-step process: first, the directly surrounding hospitals are affected through the strong connections, second all other hospitals receive introductions through the multitude of weaker links. Although the strong connections matter for local spread, weak links in the network can offer ideal routes for hospital-associated pathogens to travel further faster. This hold important implications for infection prevention and control efforts: if a local outbreak is not controlled in time, colonised patients will appear in other regions, irrespective of the distance to the initial outbreak, making import screening ever more difficult.

A standardized methodology for the surveillance of antimicrobial prescribing linked to clinical indications in primary care.

Background: A key component of strategies to reduce antimicrobial resistance is better antimicrobial prescribing. The majority of antibiotics are prescribed in primary care. While many existing surveillance systems can monitor trends in the quantities of antibiotics prescribed in this setting, it can be difficult to monitor the quality of prescribing as data on the condition for which prescriptions are issued are often not available. We devised a standardized methodology to facilitate the monitoring of condition-specific antibiotic prescribing in primary care. Methods: We used a large computerized general practitioner database to develop a standardized methodology for routine monitoring of antimicrobial prescribing linked to clinical indications in primary care in the UK. Outputs included prescribing rate by syndrome and percentages of consultations with antibiotic prescription, for recommended antibiotic, and of recommended treatment length. Results: The standardized methodology can monitor trends in proportions of common infections for which antibiotics were prescribed, the specific drugs prescribed and duration of treatment. These data can be used to help assess the appropriateness of antibiotic prescribing and to assess the impact of prescribing guidelines. Conclusions: We present a standardized methodology that could be applied to any suitable national or local database and adapted for use in other countries.

Genome analysis following a national increase in Scarlet Fever in England 2014.

BACKGROUND: During a substantial elevation in scarlet fever (SF) notifications in 2014 a national genomic study was undertaken of Streptococcus pyogenes (Group A Streptococci, GAS) isolates from patients with SF with comparison to isolates from patients with invasive disease (iGAS) to test the hypotheses that the increase in SF was due to either the introduction of one or more new/emerging strains in the population in England or the transmission of a known genetic element through the population of GAS by horizontal gene transfer (HGT) resulting in infections with an increased likelihood of causing SF. Isolates were collected to provide geographical representation, for approximately 5% SF isolates from each region from 1st April 2014 to 18th June 2014. Contemporaneous iGAS isolates for which genomic data were available were included for comparison. Data were analysed in order to determine emm gene sequence type, phylogenetic lineage and genomic clade representation, the presence of known prophage elements and the presence of genes known to confer pathogenicity and resistance to antibiotics. RESULTS: 555 isolates were analysed, 303 from patients with SF and 252 from patients with iGAS. Isolates from patients with SF were of multiple distinct emm sequence types and phylogenetic lineages. Prior to data normalisation, emm3 was the predominant type (accounting for 42.9% of SF isolates, 130/303 95%CI 37.5-48.5; 14.7% higher than the percentage of emm3 isolates found in the iGAS isolates). Post-normalisation emm types, 4 and 12, were found to be over-represented in patients with SF versus iGAS (p < 0.001). A single gene, ssa, was over-represented in isolates from patients with SF. No single phage was found to be over represented in SF vs iGAS. However, a "meta-ssa" phage defined by the presence of :315.2, SPsP6, MGAS10750.3 or HK360ssa, was found to be over represented. The HKU360.vir phage was not detected yet the HKU360.ssa phage was present in 43/63 emm12 isolates but not found to be over-represented in isolates from patients with SF. CONCLUSIONS: There is no evidence that the increased number of SF cases was a strain-specific or known mobile element specific phenomenon, as the increase in SF cases was associated with multiple lineages of GAS.

The relative importance of large problems far away versus small problems closer to home: insights into limiting the spread of antimicrobial resistance in England.

BACKGROUND: To combat the spread of antimicrobial resistance (AMR), hospitals are advised to screen high-risk patients for carriage of antibiotic-resistant bacteria on admission. This often includes patients previously admitted to hospitals with a high AMR prevalence. However, the ability of such a strategy to identify introductions (and hence prevent onward transmission) is unclear, as it depends on AMR prevalence in each hospital, the number of patients moving between hospitals, and the number of hospitals considered 'high risk'. METHODS: We tracked patient movements using data from the National Health Service of England Hospital Episode Statistics and estimated differences in regional AMR prevalences using, as an exemplar, data collected through the national reference laboratory service of Public Health England on carbapenemase-producing Enterobacteriaceae (CPE) from 2008 to 2014. Combining these datasets, we calculated expected CPE introductions into hospitals from across the hospital network to assess the effectiveness of admission screening based on defining high-prevalence hospitals as high risk. RESULTS: Based on numbers of exchanged patients, the English hospital network can be divided into 14 referral regions. England saw a sharp increase in numbers of CPE isolates referred to the national reference laboratory over 7 years, from 26 isolates in 2008 to 1649 in 2014. Large regional differences in numbers of confirmed CPE isolates overlapped with regional structuring of patient movements between hospitals. However, despite these large differences in prevalence between regions, we estimated that hospitals received only a small proportion (1.8%) of CPE-colonised patients from hospitals outside their own region, which decreased over time. CONCLUSIONS: In contrast to the focus on import screening based on assigning a few hospitals as 'high risk', patient transfers between hospitals with small AMR problems in the same region often pose a larger absolute threat than patient transfers from hospitals in other regions with large problems, even if the prevalence in other regions is orders of magnitude higher. Because the difference in numbers of exchanged patients, between and within regions, was mostly larger than the difference in CPE prevalence, it would be more effective for hospitals to focus on their own populations or region to inform control efforts rather than focussing on problems elsewhere.

Improving feedback of surveillance data on antimicrobial consumption, resistance and stewardship in England: putting the data at your Fingertips.

The provision of better access to and use of surveillance data is a key component of the UK 5 Year Antimicrobial Resistance (AMR) Strategy. Since April 2016, PHE has made data on practice (infection prevention and control; antimicrobial stewardship) and outcome (prevalence of AMR, antibiotic use and healthcare-associated infections) available through Fingertips, a publicly accessible web tool (https://fingertips.phe.org.uk/profile/amr-local-indicators). Fingertips provides access to a wide range of public health data presented as thematic profiles, with the above data being available through the 'AMR local indicators' profile. Local data on a range of indicators can be viewed at the level of National Health Service acute trusts, Clinical Commissioning Groups or general practitioner practices, all of which can be compared with the corresponding aggregate values for England to allow benchmarking. The data can be viewed in a range of formats including an overview showing counts and rates, interactive maps, spine charts and graphs that show temporal trends over a range of time scales or allow correlations between pairs of indicators. The aim of the AMR local indicators profile on Fingertips is to support the development of local action plans to optimize antibiotic prescribing and reduce AMR and healthcare-associated infections. Provision of access to relevant information in an easy to use format will help local stakeholders, including healthcare staff, commissioners, Directors of Public Health, academics and the public, to benchmark relevant local AMR data and to monitor the impact of local initiatives to tackle AMR over time.

Contribution of JAC to antimicrobial stewardship.

Antimicrobial stewardship programmes are increasingly being used to improve the quality of antimicrobial prescribing, with the dual aim of optimizing clinical outcomes and minimizing the emergence and spread of antimicrobial resistance. The Journal of Antimicrobial Chemotherapy (JAC) is celebrating its 40th anniversary and, as part of activities to commemorate this event, this article highlights the contribution of JAC to antimicrobial stewardship. Papers published in JAC have contributed to the evidence base for stewardship, have highlighted educational and behavioural change initiatives aimed at improving antibiotic prescribing practice, and have actively sought to foster the practice of antimicrobial stewardship amongst its readers.

Transferable resistance to colistin: a new but old threat.

In this Leading article, we summarize current knowledge of the occurrence of the first and so far only transferable colistin resistance gene, mcr-1 Its location on a conjugative plasmid is likely to have driven its spread into a range of enteric bacteria in humans and animals. Screening studies have identified mcr-1 in five of the seven continents and retrospective studies in China have identified this gene in Escherichia coli originally isolated in the 1980s, while the first European isolate dates back to 2005. Based on the widespread use of colistin in pigs and poultry in several countries and the higher number of mcr-1-carrying isolates of animal origin than of human origin, it is tempting to assume that this resistance may have emerged in the animal sector. Whatever its origin, interventions to reduce its further spread will require an integrated global one-health approach, comprising robust antibiotic stewardship to reduce unnecessary colistin use, improved infection prevention, and control and surveillance of colistin usage and resistance in both veterinary and human medicine.

Selecting appropriate empirical antibiotic regimens for paediatric bloodstream infections: application of a Bayesian decision model to local and pooled antimicrobial resistance surveillance data.

OBJECTIVES: The objective of this study was to evaluate the ability of weighted-incidence syndromic combination antibiograms (WISCAs) to inform the selection of empirical antibiotic regimens for suspected paediatric bloodstream infections (BSIs) by comparing WISCAs derived using data from single hospitals and from a multicentre surveillance dataset. METHODS: WISCAs were developed by estimating the coverage of five empirical antibiotic regimens for childhood BSI using a Bayesian decision tree. The study used microbiological data on ∼2000 bloodstream isolates collected over 2 years from 19 European hospitals. We evaluated the ability of a WISCA to show differences in regimen coverage at two exemplar hospitals. For each, a WISCA was first calculated using only their local data; a second WISCA was calculated using pooled data from all 19 hospitals. RESULTS: The estimated coverage of the five regimens was 72%-86% for Hospital 1 and 79%-94% for Hospital 2, based on their own data. In both cases, the best regimens could not be definitively identified because the differences in coverage were not statistically significant. For Hospital 1, coverage estimates derived using pooled data gave sufficient precision to reveal clinically important differences among regimens, including high coverage provided by a narrow-spectrum antibiotic combination. For Hospital 2, the hospital and pooled data showed signs of heterogeneity and the use of pooled data was judged not to be appropriate. CONCLUSIONS: The Bayesian WISCA provides a useful approach to pooling information from different sources to guide empirical therapy and could increase confidence in the selection of narrow-spectrum regimens.

Non-susceptibility of Escherichia coli, Klebsiella spp., Pseudomonas spp., Streptococcus pneumoniae and Staphylococcus aureus in the UK: temporal trends in England, Northern Ireland, Scotland and Wales.

OBJECTIVES: To monitor and compare trends in the non-susceptibility of bloodstream isolates of pathogens to key antibiotics in the constituent countries of the UK between 2010 and 2014. METHODS: Routinely generated antibiotic susceptibility test results for bloodstream isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Pseudomonas spp., Streptococcus pneumoniae and Staphylococcus aureus were collected from hospital microbiology laboratories in each country. RESULTS: With the exception of a decrease in the proportion of S. aureus that were MRSA, non-susceptibility to key antibiotics among the pathogens studied remained largely unchanged over the 5 year study period, with any increases in non-susceptibility being small. Although some intercountry variation in the proportions of non-susceptible isolates was seen, apart from MRSA, the differences were generally small (<5%) and fluctuated from year to year, with no country showing consistently higher or lower rates of resistance. CONCLUSIONS: Collaboration between the constituent countries of the UK allows an integrated approach to nationwide surveillance of antibiotic resistance.

Detection of the plasmid-mediated mcr-1 gene conferring colistin resistance in human and food isolates of Salmonella enterica and Escherichia coli in England and Wales.

OBJECTIVES: In response to the first report of transmissible colistin resistance mediated by the mcr-1 gene in Escherichia coli and Klebsiella spp. from animals and humans in China, we sought to determine its presence in Enterobacteriaceae isolated in the UK. METHODS: The PHE archive of whole-genome sequences of isolates from surveillance collections, submissions to reference services and research projects was retrospectively analysed for the presence of mcr-1 using Genefinder. The genetic environment of the gene was also analysed. RESULTS: Rapid screening of the genomes of ∼24 000 Salmonella enterica, E. coli, Klebsiella spp., Enterobacter spp., Campylobacter spp. and Shigella spp. isolated from food or humans identified 15 mcr-1-positive isolates. These comprised: 10 human S. enterica isolates submitted between 2012 and 2015 (8 Salmonella Typhimurium, 1 Salmonella Paratyphi B var Java and 1 Salmonella Virchow) from 10 patients; 3 isolates of E. coli from 2 patients; and 2 isolates of Salmonella Paratyphi B var Java from poultry meat imported from the EU. The mcr-1 gene was located on diverse plasmids belonging to the IncHI2, IncI2 and IncX4 replicon types and its association with ISApl1 varied. Six mcr-1-positive S. enterica isolates were from patients who had recently travelled to Asia. CONCLUSIONS: Analysis of WGS data allowed rapid confirmation of the presence of the plasmid-mediated colistin resistance gene mcr-1 in diverse genetic environments and plasmids. It has been present in E. coli and Salmonella spp. harboured by humans in England and Wales since at least 2012.

Descriptive epidemiology of Escherichia coli bacteraemia in England, April 2012 to March 2014.

We determined the incidence, risk factors and antimicrobial susceptibility associated with Escherichia coli bacteraemia in England over a 24 month period. Case data were obtained from the national mandatory surveillance database, with susceptibility data linked from LabBase2, a voluntary national microbiology database. Between April 2012 and March 2014, 66,512 E. coli bacteraemia cases were reported. Disease incidence increased by 6% from 60.4 per 100,000 population in 2012-13 to 63.5 per 100,000 population in 2013-14 (p < 0.0001). Rates of E. coli bacteraemia varied with patient age and sex, with 70.5% (46,883/66,512) of cases seen in patients aged ≥ 65 years and 52.4% (33,969/64,846) of cases in females. The most common underlying cause of bacteraemia was infection of the genital/urinary tract (41.1%; 27,328/66,512), of which 98.4% (26,891/27,328) were urinary tract infections (UTIs). The majority of cases (76.1%; 50,617/66,512) had positive blood cultures before or within two days of admission and were classified as community onset cases, however 15.7% (10,468/66,512) occurred in patients who had been hospitalised for over a week. Non-susceptibility to ciprofloxacin, third-generation cephalosporins, piperacillin-tazobactam, gentamicin and carbapenems were 18.4% (8,439/45,829), 10.4% (4,256/40,734), 10.2% (4,694/46,186), 9.7% (4,770/49,114) and 0.2% (91/42,986), respectively. Antibiotic non-susceptibility was higher in hospital-onset cases than for those presenting from the community (e.g. ciprofloxacin non-susceptibility was 22.1% (2,234/10,105) for hospital-onset vs 17.4% (5,920/34,069) for community-onset cases). Interventions to reduce the incidence of E. coli bacteraemia will have to target the community setting and UTIs if substantial reductions are to be realised.

Longitudinal trends and cross-sectional analysis of English national hospital antibacterial use over 5 years (2008-13): working towards hospital prescribing quality measures.

OBJECTIVES: There is global concern that antimicrobial resistance is a major threat to healthcare. Antimicrobial use is a primary driver of resistance but little information exists about the variation in antimicrobial use in individual hospitals in England over time or comparative use between hospitals. The objective of this study was to collate, analyse and report issue data from pharmacy records of 158 National Health Service (NHS) acute hospitals. METHODS: This was a cohort study of inpatient antibacterial use in acute hospitals in England analysed over 5 years through a data warehouse from IMS Health, a leading provider of information, services and technology for the healthcare industry. Around 98% of NHS hospitals were included in a country with a population of 50 million residents. RESULTS: There was a dramatic change in the usage of different groups of antibacterials between 2009 and 2013 with a marked reduction in the use of first-generation cephalosporins by 24.7% and second-generation cephalosporins by 41%, but little change in the use of third-generation cephalosporins (+5.7%) and fluoroquinolones (+1.6%). In contrast, use of co-amoxiclav, carbapenems and piperacillin/tazobactam increased by 60.1%, 61.4% and 94.8%, respectively. There was wide variation in the total and relative amounts of antibacterials used between individual hospitals. CONCLUSIONS: Longitudinal analysis of antibacterial use demonstrated remarkable changes in NHS hospitals, probably reflecting governmental and professional guidance to mitigate the risk of Clostridium difficile infection. The wide variation in usage between individual hospitals suggests potential for quality improvement and benchmarking. Quality measures of optimal hospital antimicrobial prescribing need urgent development and validation to support antimicrobial stewardship initiatives.