Glasgow, United Kingdom
Glasgow, United Kingdom

Time filter

Source Type

Van Bunnik B.A.D.,University of Edinburgh | Ciccolini M.,University of Groningen | Gibbons C.L.,University of Edinburgh | Edwards G.,Scottish MRSA Reference Laboratory | And 5 more authors.
BMC Public Health | Year: 2015

Background: Detecting novel healthcare-associated infections (HCAI) as early as possible is an important public health priority. However, there is currently no evidence base to guide the design of efficient and reliable surveillance systems. Here we address this issue in the context of a novel pathogen spreading primarily between hospitals through the movement of patients. Methods: Using a mathematical modelling approach we compare the current surveillance system for a HCAI that spreads primarily between hospitals due to patient movements as it is implemented in Scotland with a gold standard to determine if the current system is maximally efficient or whether it would be beneficial to alter the number and choice of hospitals in which to concentrate surveillance effort. Results: We validated our model by demonstrating that it accurately predicts the risk of meticillin-resistant Staphylococcus aureus bacteraemia cases in Scotland. Using the 29 (out of 182) sentinel hospitals that currently contribute most of the national surveillance effort results in an average detection time of 117 days. A reduction in detection time to 87 days is possible by optimal selection of 29 hospitals. Alternatively, the same detection time (117 days) can be achieved using just 22 optimally selected hospitals. Increasing the number of sentinel hospitals to 38 (teaching and general hospitals) reduces detection time by 43 days; however decreasing the number to seven sentinel hospitals (teaching hospitals) increases detection time substantially to 268 days. Conclusions: Our results show that the current surveillance system as it is used in Scotland is not optimal in detecting novel pathogens when compared to a gold standard. However, efficiency gains are possible by better choice of sentinel hospitals, or by increasing the number of hospitals involved in surveillance. Similar studies could be used elsewhere to inform the design and implementation of efficient national, hospital-based surveillance systems that achieve rapid detection of novel HCAIs for minimal effort. © 2015 van Bunnik et al.


PubMed | Royal Infirmary, University of Groningen, Roslin Institute, University of Edinburgh and Scottish MRSA Reference Laboratory
Type: | Journal: BMC public health | Year: 2015

Detecting novel healthcare-associated infections (HCAI) as early as possible is an important public health priority. However, there is currently no evidence base to guide the design of efficient and reliable surveillance systems. Here we address this issue in the context of a novel pathogen spreading primarily between hospitals through the movement of patients.Using a mathematical modelling approach we compare the current surveillance system for a HCAI that spreads primarily between hospitals due to patient movements as it is implemented in Scotland with a gold standard to determine if the current system is maximally efficient or whether it would be beneficial to alter the number and choice of hospitals in which to concentrate surveillance effort.We validated our model by demonstrating that it accurately predicts the risk of meticillin-resistant Staphylococcus aureus bacteraemia cases in Scotland. Using the 29 (out of 182) sentinel hospitals that currently contribute most of the national surveillance effort results in an average detection time of 117 days. A reduction in detection time to 87 days is possible by optimal selection of 29 hospitals. Alternatively, the same detection time (117 days) can be achieved using just 22 optimally selected hospitals. Increasing the number of sentinel hospitals to 38 (teaching and general hospitals) reduces detection time by 43 days; however decreasing the number to seven sentinel hospitals (teaching hospitals) increases detection time substantially to 268 days.Our results show that the current surveillance system as it is used in Scotland is not optimal in detecting novel pathogens when compared to a gold standard. However, efficiency gains are possible by better choice of sentinel hospitals, or by increasing the number of hospitals involved in surveillance. Similar studies could be used elsewhere to inform the design and implementation of efficient national, hospital-based surveillance systems that achieve rapid detection of novel HCAIs for minimal effort.


PubMed | Institute Salud Carlos III, University of Lyon, Chinese National Institute for Communicable Disease Control and Prevention, University of Groningen and 10 more.
Type: Journal Article | Journal: Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases | Year: 2015

Methicillin-resistant Staphylococcus aureus (MRSA) belonging to the multilocus sequence type clonal complex 59 (MLST CC59) is the predominant community-associated MRSA clone in Asia. This clone, which is primarily linked with the spa type t437, has so far only been reported in low numbers among large epidemiological studies in Europe. Nevertheless, the overall numbers identified in some Northern European reference laboratories have increased during the past decade. To determine whether the S. aureus t437 clone is present in other European countries, and to assess its genetic diversity across Europe, we analysed 147 S. aureus t437 isolates from 11 European countries collected over a period of 11 years using multiple locus variable number tandem repeat fingerprinting/analysis (MLVF/MLVA) and MLST. Additionally 16 S. aureus t437 isolates from healthy carriers and patients from China were included. Most isolates were shown to be monophyletic with 98% of the isolates belonging to the single MLVA complex 621, to which nearly all included isolates from China also belonged. More importantly, all MLST-typed isolates belonged to CC59. Our study implies that the European S. aureus t437 population represents a genetically tight cluster, irrespective of the year, country and site of isolation. This underpins the view that S. aureus CC59 has been introduced into several European countries, not being restricted to particular geographical regions or specific host environments. The European S. aureus t437 isolates thus bear the general hallmarks of a high-risk clone.


van Velzen E.V.H.,Health Protection Scotland | van Velzen E.V.H.,Centers for Disease Control and Prevention | Reilly J.S.,Health Protection Scotland | Kavanagh K.,University of Strathclyde | And 6 more authors.
Infection Control and Hospital Epidemiology | Year: 2011

Objective. To estimate the proportion of patients who acquire methicillin-resistant Staphylococcus aureus (MRSA) while in hospital and to identify risk factors associated with acquisition of MRSA. Design. Retrospective cohort study. Patients. Adult patients discharged from 36 general specialty wards of 2 Scottish hospitals that had implemented universal screening for MRSA on admission. Methods. Patients were screened for MRSA on discharge from hospital by using multisite body swabs that were tested by culture. Discharge screening results were linked to admission screening results. Genotyping was undertaken to identify newly acquired MRSA in MRSA-positive patients on admission. Results. Of the 5,155 patients screened for MRSA on discharge, 2.9% (95% confidence interval [CI], 2.43-3.34) were found to be positive. In the subcohort screened on both admission and discharge (n=2,724), 1.3% of all patients acquired MRSA while in hospital (incidence rate, 2.1/1,000 hospital bed-days in this cohort [95% CI, 1.5-2.9]), while 1.3% remained MRSA positive throughout hospital stay. Three risk factors for acquisition of MRSA were identified: age above 64 years, self-reported renal failure, and self-reported presence of open wounds. On a population level, the prevalence of MRSA colonization did not differ between admission and discharge. conclusions. Cross-transmission of MRSA takes place in Scottish hospitals that have implemented universal screening for MRSA. This study reinforces the importance of infection prevention and control measures to prevent MRSA cross-transmission in hospitals; universal screening for MRSA on admission will in itself not be sufficient to reduce the number of MRSA colonizations and subsequent MRSA infections. © 2011 by The Society for Healthcare Epidemiology of America All rights reserved.


Lawes T.,Royal Aberdeen Childrens Hospital | Lopez-Lozano J.-M.,Hospital Vega Baja | Nebot C.,Centro Universitario Of La Defensa Cud Of San Javier | Macartney G.,Royal Infirmary | And 4 more authors.
BMJ Open | Year: 2015

Objectives: To explore temporal associations between planned antibiotic stewardship and infection control interventions and the molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA). Design: Retrospective ecological study and time-series analysis integrating typing data from the Scottish MRSA reference laboratory. Setting: Regional hospital and primary care in a Scottish Health Board. Participants: General adult (N=1 051 993) or intensive care (18 235) admissions and primary care registrations (460 000 inhabitants) between January 1997 and December 2012. Interventions: Hand-hygiene campaign; MRSA admission screening; antibiotic stewardship limiting use of macrolides and '4Cs' (cephalosporins, coamoxiclav, clindamycin and fluoroquinolones). Outcome measures: Prevalence density of MRSA clonal complexes CC22, CC30 and CC5/Other in hospital (isolates/1000 occupied bed days, OBDs) and community (isolates/10 000 inhabitant-days). Results: 67% of all clinical MRSA isolates (10 707/15 947) were typed. Regional MRSA population structure was dominated by hospital epidemic strains CC30, CC22 and CC45. Following declines in overall MRSA prevalence density, CC5 and other strains of community origin became increasingly important. Reductions in use of '4Cs' and macrolides anticipated declines in sublineages with higher levels of associated resistances. In multivariate time-series models (R2=0.63-0.94) introduction of the hand-hygiene campaign, reductions in mean length of stay (when >4 days) and bed occupancy (when >74 to 78%) predicted declines in CC22 and CC30, but not CC5/other strains. Lower importation pressures, expanded MRSA admission screening, and reductions in macrolide and third generation cephalosporin use (thresholds for association: 135-141, and 48-81 defined daily doses/1000 OBDs, respectively) were followed by declines in all clonal complexes. Strain-specific associations with fluoroquinolones and clindamycin reflected resistance phenotypes of clonal complexes. Conclusions: Infection control measures and changes in population antibiotic use were important predictors of MRSA strain dynamics in our region. Strategies to control MRSA should consider thresholds for effects and strain-specific impacts. © 2015, BMJ. All rights reserved.


Holmes A.,Roslin Institute | Mcallister G.,Roslin Institute | Mcadam P.R.,Roslin Institute | Hsien Choi S.,Royal Infirmary | And 5 more authors.
Clinical Microbiology and Infection | Year: 2014

The EMRSA-15 clone is a major cause of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infections in the UK and elsewhere but existing typing methodologies have limited capacity to discriminate closely related strains, and are often poorly reproducible between laboratories. Here, we report the design, development and validation of a genome-wide single nucleotide polymorphism (SNP) typing method and compare it to established methods for typing of EMRSA-15. In order to identify discriminatory SNPs, the genomes of 17 EMRSA-15 strains, selected to represent the breadth of genotypic and phenotypic diversity of EMRSA-15 isolates in Scotland, were determined and phylogenetic reconstruction was carried out. In addition to 17 phylogenetically informative SNPs, five binary markers were included to form the basis of an EMRSA-15 genotyping assay. The SNP-based typing assay was as discriminatory as pulsed-field gel electrophoresis, and significantly more discriminatory than staphylococcal protein A (spa) typing for typing of a representative panel of diverse EMRSA-15 strains, isolates from two EMRSA-15 hospital outbreak investigations, and a panel of bacteraemia isolates obtained in healthcare facilities in the east of Scotland during a 12-month period. The assay is a rapid, and reproducible approach for epidemiological analysis of EMRSA-15 clinical isolates in Scotland. Unlike established methods the DNA sequence-based method is ideally suited for inter-laboratory comparison of identified genotypes, and its flexibility lends itself to supplementation with additional SNPs or markers for the identification of novel S. aureus strains in other regions of the world. © 2013 European Society of Clinical Microbiology and Infectious Diseases.


PubMed | Royal Infirmary, Hospital Vega Baja, Royal Aberdeen Childrens Hospital, Centro Universitario Of La Defensa Cud Of San Javier and Scottish MRSA Reference Laboratory
Type: Journal Article | Journal: BMJ open | Year: 2015

To explore temporal associations between planned antibiotic stewardship and infection control interventions and the molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA).Retrospective ecological study and time-series analysis integrating typing data from the Scottish MRSA reference laboratory.Regional hospital and primary care in a Scottish Health Board.General adult (N=1,051,993) or intensive care (18,235) admissions and primary care registrations (460,000 inhabitants) between January 1997 and December 2012.Hand-hygiene campaign; MRSA admission screening; antibiotic stewardship limiting use of macrolides and 4Cs (cephalosporins, coamoxiclav, clindamycin and fluoroquinolones).Prevalence density of MRSA clonal complexes CC22, CC30 and CC5/Other in hospital (isolates/1000 occupied bed days, OBDs) and community (isolates/10,000 inhabitant-days).67% of all clinical MRSA isolates (10,707/15,947) were typed. Regional MRSA population structure was dominated by hospital epidemic strains CC30, CC22 and CC45. Following declines in overall MRSA prevalence density, CC5 and other strains of community origin became increasingly important. Reductions in use of 4Cs and macrolides anticipated declines in sublineages with higher levels of associated resistances. In multivariate time-series models (R(2)=0.63-0.94) introduction of the hand-hygiene campaign, reductions in mean length of stay (when >4days) and bed occupancy (when >74 to 78%) predicted declines in CC22 and CC30, but not CC5/other strains. Lower importation pressures, expanded MRSA admission screening, and reductions in macrolide and third generation cephalosporin use (thresholds for association: 135-141, and 48-81 defined daily doses/1000 OBDs, respectively) were followed by declines in all clonal complexes. Strain-specific associations with fluoroquinolones and clindamycin reflected resistance phenotypes of clonal complexes.Infection control measures and changes in population antibiotic use were important predictors of MRSA strain dynamics in our region. Strategies to control MRSA should consider thresholds for effects and strain-specific impacts.


Ward M.J.,University of Edinburgh | Goncheva M.,Roslin Institute | Richardson E.,Roslin Institute | McAdam P.R.,Roslin Institute | And 11 more authors.
Genome Biology | Year: 2016

Background: Our understanding of the factors influencing the emergence, dissemination and global distribution of epidemic clones of bacteria is limited. ST59 is a major epidemic clone of community-associated MRSA in East Asia, responsible for extensive morbidity and mortality, but has a much lower prevalence in other parts of the world. The geographic origin of ST59 and its international routes of dissemination are unclear and disputed in the literature. Results: To investigate the origin and spread of the ST59 clone, we obtained whole genome sequences of isolates from four continents, sampled over more than a decade, and carried out a time-scaled phylogeographic analysis. We discover that two distinct ST59 clades emerged concurrently, in East Asia and the USA, but underwent clonal expansion at different times. The East Asia clade was strongly enriched for gene determinants associated with antibiotic resistance, consistent with regional differences in antibiotic usage. Both clones spread independently to Australia and Europe, and we found evidence of the persistence of multi-drug resistance following export from East Asia. Direct transfer of strains between Taiwan and the USA was not observed in either direction, consistent with geographic niche exclusion. Conclusions: Our results resolve a longstanding controversy regarding the origin of the ST59 clone, revealing the major global source and sink populations and routes for the spread of multi-drug resistant clones. Additionally, our findings indicate that diversification of the accessory genome of epidemic clones partly reflects region-specific patterns of antibiotic usage, which may influence bacterial fitness after transmission to different geographic locations. © 2016 The Author(s).


Stegger M.,Statens Serum Institute | Andersen P.S.,Statens Serum Institute | Kearns A.,Public Health England | Pichon B.,Public Health England | And 6 more authors.
Clinical Microbiology and Infection | Year: 2012

The recent finding of a new mecA homologue, mecA LGA251, with only 70% nucleotide homology to the conventional mecA gene has brought the routine testing for mecA as a confirmatory test for methicillin-resistant Staphylococcus aureus (MRSA) into question. A multiplex PCR was designed to differentiate mecA LGA251 from the known mecA together with detection of lukF-PV and the spa gene fragments, enabling direct spa typing by sequencing of the PCR amplicons. The PCR analysis and subsequent spa typing were validated on a large collection (n=185) of contemporary MRSA and methicillin-sensitive S. aureus isolates, including 127 isolates carrying mecA LGA251. The mecA LGA251 gene was situated in staphylococcal cassette chromosome mec type XI elements, and sequence variation within a 631-bp fragment of mecA LGA251 in 79 isolates indicated a very conserved gene sequence. Following a successful validation, the multiplex PCR strategy was implemented in the routine testing of MRSA for national surveillance. Over a 2-month period, among 203 samples tested, 12 new MRSA cases caused by isolates carrying mecA LGA251 were identified, emphasizing the clinical importance of testing for these new MRSA isolates. © 2011 Statens Serum Institut. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.


Rao G.G.,North West London Hospitals | Kearns A.M.,Public Health England | Edwards G.F.S.,Scottish MRSA Reference Laboratory
Journal of Hospital Infection | Year: 2011

Epidemic meticillin-resistant Staphylococcus aureus-16, which was widespread throughout the UK and the rest of the world, has declined markedly in recent years. The reasons for this are not clear. © 2011 The Healthcare Infection Society.

Loading Scottish MRSA Reference Laboratory collaborators
Loading Scottish MRSA Reference Laboratory collaborators