Intermittent point prevalence surveys on healthcare-associated infections, 2011 and 2016, in England: what are the surveillance and intervention priorities?

BACKGROUND: Point prevalence surveys are an important surveillance method for determining the burden of healthcare-associated infections (HCAIs). AIM: To outline the key results of two point prevalence surveys in England (2011 and 2016). METHODS: All National Health Service and independent sector hospitals in England were eligible to participate. Data were collected between September and November in both 2011 and 2016 based on the protocol and codebook devised by the European Centre for Disease Prevention and Control. Analysis was performed using Stata Version 13 and SAS Version 9.3. A mixed-effects model was applied, which allowed estimation of organization-specific means and accounted for the heterogeneity in the responses from different organizations. FINDINGS: A total of 100,755 case records were included (52,433 in 2011 and 48,312 in 2016). The estimated prevalence of HCAIs was slightly higher in 2016 [6.89%, 95% confidence interval (CI) 6.21-7.57%] than in 2011 (6.41%, 95% CI 5.75-7.06%). In both surveys, the prevalence of HCAIs was highest in adult intensive care units (23.1% in 2011, 21.2% in 2016), and pneumonia/lower respiratory tract infections was the most common cause of HCAIs (22.7% in 2011 vs 29.2% in 2016). Inpatients in acute hospitals were older and had higher risk of dying in 2016 compared with 2011; however, the proportion of inpatients with HCAIs or on antibiotics did not differ significantly. CONCLUSION: The burden of HCAIs in English hospitals increased slightly between 2011 and 2016. However, the proportion of inpatients with HCAIs or on antibiotics did not differ significantly.

Impact of national policies on the microbial aetiology of surgical site infections in acute NHS hospitals in England: analysis of trends between 2000 and 2013 using multi-centre prospective cohort data.

Our study aimed to evaluate changes in the epidemiology of pathogens causing surgical site infections (SSIs) in England between 2000 and 2013 in the context of intensified national interventions to reduce healthcare-associated infections introduced since 2006. National prospective surveillance data on target surgical procedures were used for this study. Data on causative organism were available for 72% of inpatient-detected SSIs meeting the standard case definitions for superficial, deep and organ-space infections (9767/13 531) which were analysed for trends. A multivariable logistic linear mixed model with hospital random effects was fitted to evaluate trends by pathogen. Staphylococcus aureus was the predominant cause of SSI between 2000 (41%) and 2009 (24%), decreasing from 2006 onwards reaching 16% in 2013. Data for 2005-2013 showed that the odds of SSI caused by S. aureus decreased significantly by 14% per year [adjusted odds ratio (aOR) 0·86, 95% confidence interval (CI) 0·83-0·89] driven by significant decreases in methicillin-resistant S. aureus (MRSA) (aOR 0·71, 95% CI 0·68-0·75). However a small significant increase in methicillin-sensitive S. aureus was identified (aOR 1·06, 95% CI 1·02-1·10). Enterobacteriaceae were stable during 2000-2007 (12% of cases overall), increasing from 2008 (18%) onwards, being present in 25% of cases in 2013; the model supported these increasing trends during 2007-2013 (aOR 1·12, 95% CI 1·07-1·18). The decreasing trends in S. aureus SSIs from 2006 and the increases in Enterobacteriaceae SSIs from 2008 may be related to intensified national efforts targeted at reducing MRSA bacteraemia combined with changes in antibiotic use aimed at controlling C. difficile infections.

GENETIC VARIATION AND IDENTIFICATION OF PROMISING SOUR CHERRIES INFERRED FROM MICROSATELLITE MARKERS.

The aim of this study was to identify the group of highly polymorphic microsatellite markers for identification of promising sour cherries. From among 30 tested microsatellite (SSR) markers, 19 were selected to profile genetic variation in sour cherries due to high polymorphisms. Results indicated a high level of polymorphism of the accessions based on these markers. Totally 148 alleles were generated at 19 SSR loci which 122 alleles were polymorphic. The number of total alleles per locus ranged from 2 to 15 with an average of 7.78 and polymorphism percentage varied from 50 to 100% with an average of 78.76%. Also, PIC varied from 0.47 to 0.89 with an average of 0.79 and heterozygosity ranged from 0.35 to 0.55 with a mean of 0.45. According to these results, these markers specially PMS3, PS12A02, PceGA34, BPPCT021, EMPA004, EMPA018, and Pchgms3 produced good and various levels of amplifications and showed high heterozygosity levels. By the way, the genetic similarity showed a high diversity among the sour cherries. Cluster analysis separated improved cultivars from promising sour cherries, and the PCoA supported the cluster analysis results. Since the studied sour cherries were superior to the improved cultivars and were separated from them in most groups, these sour cherries can be considered as distinct genotypes for further evaluations in the framework of breeding programs and new cultivar identification in cherries. Results also confirmed that the set of microsatellite markers employed in this study demonstrated usefulness of microsatellite markers for the identification of sour cherry genotypes.

Inter-hospital comparison of rates of surgical site infection following caesarean section delivery: evaluation of a multicentre surveillance study.

BACKGROUND: Short postoperative stays following caesarean section delivery make it difficult to assess accurately the risk of surgical site infection (SSI). Methods of case-finding that minimize variation are required to support effective surveillance systems, especially where used for benchmarking. AIM: To evaluate the efficacy of case-finding methods for SSI following caesarean delivery and their utility in establishing benchmark rates of SSI. METHODS: Hospitals conducted surveillance over one or two 13-week periods. Patients were reviewed during their inpatient stay, post partum by community midwives and via patient questionnaire at 30 days post delivery. To estimate the reliability of case-finding methods, case-note reviews were undertaken in a random sample of four hospitals. FINDINGS: A total of 404 SSIs were detected in 4107 caesarean deliveries from 14 hospitals. The median time to SSI was 10 days, 66% were detected in-hospital or by community midwives, and an additional 34% were patient-reported. The rate of SSI was 9.8% but the proportion of patients followed up varied significantly between centres. The estimated sensitivity and specificity of case-finding was 91.4% [95% confidence interval (CI): 53.4-98.4] and 98.6% (95% CI: 98.4-98.8), the positive predictive value 91.0% (95% CI: 82.4-96.1) and negative predictive value 98.6% (95% CI: 93.9-99.5). CONCLUSIONS: Combined case ascertainment methods are a feasible way to achieve active post-discharge surveillance and had high negative and positive predictive values. Additional SSIs can be detected by patient questionnaires but rates of SSI were strongly influenced by variation in intensity of both healthcare worker- and patient-based case-finding. This factor must be taken into account when comparing or benchmarking rates of SSI.

A methodological approach to investigating a nationwide clinical specimen contamination problem in England.

Outbreaks of pseudo-infection due to contamination of specimens have been described, often as localised incidents. From August 2006, several English hospital laboratories began to refer an unusually high number of isolates of the fungus Paecilomyces variotii from clinical specimens to the national mycology reference laboratory for microbiological testing. We describe the methods used during the outbreak investigation in order to provide infection control specialists with an overview of how such national incidents may be investigated. We surveyed the hospitals reporting the contamination problem and conducted microbiological and environmental sampling. We applied analytical epidemiology to supply chain data, comparing the supply lines of key equipment to affected and unaffected hospitals in England. The survey was useful to describe procedures and equipment in use in the hospitals reporting the problem. The microbiological aspects of the investigation helped us understand how the fungal spores were distributed in the hospital environment. In the supply chain investigation we used data that was previously only used for logistical purposes. Overall the investigation was methodologically challenging, with no existing protocol to guide the investigators. To our knowledge, this is a novel approach to the investigation of such a widespread contamination problem, affecting geographically disparate hospitals at the same time.

Deviations of drug solubility in water-cosolvent mixtures from the Jouyban-Acree model--effect of solute structure.

Deviations of the predicted solubilities using the Jouyban-Acree model from experimental data were correlated to the structural descritptors of the drugs computed by HyperChem software. The proposed models are able to predict the solubility in water-cosolvent mixtures and reduced the mean percentage deviations (MPD) of predicted solubilities from 24%, 48%, and 53% to 16%, 33% and 38%, respectively for water-propylene glycol, water-ethanol and water-polyethylene glycol 400 mixtures, with the overall improvement in prediction capability of the model being approximately 13%.

Threshold models in a methadone programme evaluation.

The degree of non-compliance with a methadone programme is such that a zero is often recorded as the response variable. Such outcome variables cannot be transformed to normality in order to investigate a regression relationship between the response variable and various risk or treatment variables. The presence of a random effect as well in this regression causes added difficulty in the analysis. We show here that use of threshold models can provide a satisfactory solution to both these problems.