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.

Rates of surgical site infection after hip replacement as a hospital performance indicator: analysis of data from the English mandatory surveillance system.

OBJECTIVE: To describe rates of surgical site infection (SSI) after hip replacement and to use these data to provide a simple mechanism for identifying poorly performing hospitals that takes into account variations in sample size. DESIGN: Prospective surveillance study. SETTING: A total of 125 acute care hospitals in England that participated in mandatory SSI surveillance from April 1, 2004 through March 31, 2005. PATIENTS: Patients who underwent total hip replacement (THR) or hip hemiarthroplasty (HH). METHODS: A standard data set was collected for all eligible operations at participating hospitals for a minimum of 3 months annually. Defined methods were used to identify SSIs that occurred during the inpatient stay. Data were checked for quality and accuracy, and funnel plots were constructed by plotting the incidence of SSI against the number of operations. RESULTS: Data were collected on 16,765 THRs and 5,395 HHs. The cumulative SSI incidence rates were 1.26% for THR and 4.06% for HH; the incidence densities were 1.38 SSIs per 1,000 postoperative inpatient days for THR and 2.3 SSIs per 1,000 postoperative inpatient days for HH. The risk of infection associated with revision surgery was significantly higher than that associated with primary surgery (2.7% [95% confidence interval, 2.0%-3.5%] vs. 1.1% [95% confidence interval, 1.0%-1.2%]; P=.003). Rates varied considerably among hospitals. Nineteen hospitals had rates above the 90th percentile. However, the use of funnel plots to adjust for the precision of estimated SSI rates identified 7 hospitals that warranted further investigation, including 2 with crude rates below the 90th percentile. CONCLUSIONS: Funnel plots of rates of SSI after hip replacement provide a valuable method of presenting hospital performance data, clearly identifying hospitals with unusually high or low rates while adjusting for the precision of the estimated rate. This information can be used to target and support local interventions to reduce the risk of infection.

Distribution and antimicrobial susceptibility patterns of Clostridium difficile PCR ribotypes in English hospitals, 2007-08.

A surveillance study designed to provide a representative sample of the strains of Clostridium difficile causing infections in hospitals in England was in operation from April 2007 to the end of March 2008. Six hundred and seventy-seven isolates were obtained from 186 hospitals in the nine geographical regions of England as recognised by the Health Protection Agency's Regional Microbiology Network. Typing studies revealed that PCR ribotype 027 is now the most common strain isolated from symptomatic patients, accounting for over 41.3% of isolates in English hospitals. Type 106 was the second most common strain (20.2%) and Type 001, which was once the most common strain associated with hospital outbreaks, has now been reduced to only 7.8% of the total. A mixture of 44 other PCR ribotypes accounted for the remaining 28.9% of isolates. This represents a changing distribution of strains when compared to a previous study performed two years earlier which showed roughly equal proportions of types 106, 001 and 027. Antimicrobial susceptibility testing by the E test method revealed significantly lower susceptibility to metronidazole in the more common strains when compared to the less common ribotypes, although none were classified as clinically resistant. Similarly, no resistance to vancomycin was detected. However, common PCR ribotypes were more resistant to moxifloxacin and erythromycin than the less common strains, which may indicate a selective advantage for resistance to these agents, and combined resistance to these two agents was a good indicator of a common ribotype.

Endoscope decontamination incidents in England 2003-2004.

An Endoscope Task Force was established following the report of an endoscope decontamination failure in May 2004. The Task Force reviewed endoscope decontamination incidents in England from 2003 to 2004 and made recommendations to prevent further recurrences. Twenty-one incidents were reported from 19 National Health Service (NHS) Trusts, 18 of which matched the Task Force definition of an incident. Eight incidents involved failures to decontaminate auxiliary endoscope channels, seven incidents highlighted problems with automated endoscope reprocessors, and the remaining three involved disinfection practices not recommended by the British Society of Gastroenterology Guidelines. Following an assessment of the risk of transmission from blood-borne viruses, the Task Force recommended that look-back exercises were not indicated. The nature of the incidents suggested that there were problems associated with defining roles and responsibilities for endoscope decontamination, staff training and incompatibility between endoscopes and reprocessors. The Medicines and Healthcare Products Regulatory Agency subsequently issued recommendations to all NHS Trusts carrying out endoscopies.

Gastrointestinal endoscopy decontamination failure and the risk of transmission of blood-borne viruses: a review.

The risk of blood-borne virus transmission with an inadequately decontaminated endoscope during gastrointestinal endoscopy remains unclear, although it is likely to be low. A systematic review of the literature was undertaken to determine previous episodes of blood-borne virus transmission in these circumstances. In total, 31 articles were included in this review. No articles relating to possible transmission of human immunodeficiency virus were identified. The articles included were generally case series or case reports and were written prior to the comprehensive endoscope decontamination guidelines in use today. The results suggest that hepatitis B and hepatitis C transmission are low during endoscopy with an inadequately decontaminated endoscope.

Guidelines for the control and prevention of meticillin-resistant Staphylococcus aureus (MRSA) in healthcare facilities.

Meticillin-resistant Staphylococcus aureus (MRSA) remains endemic in many UK hospitals. Specific guidelines for control and prevention are justified because MRSA causes serious illness and results in significant additional healthcare costs. Guidelines were drafted by a multi-disciplinary group and these have been finalised following extensive consultation. The recommendations have been graded according to the strength of evidence. Surveillance of MRSA should be undertaken in a systematic way and should be fed back routinely to healthcare staff. The inappropriate or unnecessary use of antibiotics should be avoided, and this will also reduce the likelihood of the emergence and spread of strains with reduced susceptibility to glycopeptides, i.e. vancomycin-intermediate S. aureus/glycopeptide-intermediate S. aureus (VISA/GISA) and vancomycin-resistant S. aureus (VRSA). Screening for MRSA carriage in selected patients and clinical areas should be performed according to locally agreed criteria based upon assessment of the risks and consequences of transmission and infection. Nasal and skin decolonization should be considered in certain categories of patients. The general principles of infection control should be adopted for patients with MRSA, including patient isolation and the appropriate cleaning and decontamination of clinical areas. Inadequate staffing, especially amongst nurses, contributes to the increased prevalence of MRSA. Laboratories should notify the relevant national authorities if VISA/GISA or VRSA isolates are identified.

Man or machine in psychiatric diagnosis.

The authors describe the previous studies of the stability of psychiatric diagnoses over time that have found such diagnoses to be unreliable, stating that the assumptions underlying these studies have been tested and disproved. On the other hand, the use of standardized interview techniques and categorization by computer yield reliable symptom ratings and precise diagnoses. The authors discuss the importance of these findings to the selection of the most appropriate treatment modality for individual patients.

Adherence and survival properties of an epidemic methicillin-resistant strain of Staphylococcus aureus compared with those of methicillin-sensitive strains.

The adherence of epidemic methicillin-resistant Staphylococcus aureus-1 (EMRSA-1) to HEp2 cells and fibronectin and its survival on formica blocks were compared with the equivalent properties of methicillin-sensitive strains of S. aureus. EMRSA-1 bound to HEp2 cells and fibronectin significantly less than the other strains of S. aureus tested, but survival on formica blocks was similar for all strains except the 'Oxford' S. aureus, which survived poorly.

Production of "virulence factors" by "epidemic" methicillin-resistant Staphylococcus aureus in vitro.

The production of virulence factors was determined quantitatively for clinical isolates of methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) strains of Staphylococcus aureus from The London Hospital. The examined factors were: production of enterotoxins A, B, C and D, determined by ELISA; quantitation and differentiation of the membrane-damaging alpha, beta, gamma and delta haemolysins; and coagulase production determined by a chromogenic assay. Enterotoxin A was produced by MRSA but not by MSSA. All the strains produced haemolysins alpha, gamma and delta at similar levels, but MRSA produced significantly more coagulase than MSSA. MRSA and MSSA were compared in a phagocytosis assay but there was no difference between the phagocytosis of MRSA and MSSA by human polymorphonuclear leucocytes. These findings indicate that MRSA from The London Hospital is at least as well equipped to cause disease as other isolates of S. aureus, and probably better equipped than most hospital isolates of MSSA.

Systematic review of isolation policies in the hospital management of methicillin-resistant Staphylococcus aureus: a review of the literature with epidemiological and economic modelling.

OBJECTIVE: To review the evidence for the effectiveness of different isolation policies and screening practices in reducing the incidence of methicillin-resistant Staphylococcus aureus (MRSA) colonisation and infection in hospital in-patients. To develop transmission models to study the effectiveness and cost-effectiveness of isolation policies in controlling MRSA. DATA SOURCES: MEDLINE, EMBASE, CINAHL, The Cochrane Library and SIGLE (1966-2000). Hand-searching key journals. No language restrictions. REVIEW METHODS: Key data were extracted from articles reporting MRSA-related outcomes and describing an isolation policy in a hospital with epidemic or endemic MRSA. No quality restrictions were imposed on studies using isolation wards (IW) or nurse cohorting (NC). Other studies were included if they were prospective or employed planned comparisons of retrospective data. Stochastic and deterministic models investigated long-term transmission dynamics, studying the effect of a fixed capacity IW, producing economic evaluations using local cost data. RESULTS: A total of 46 studies were accepted: 18 IWs, 9 NC, 19 other isolation policies. Most were interrupted time series, with few planned formal prospective studies. All but one reported multiple interventions. Consideration of potential confounders, measures to prevent bias, and appropriate statistical analysis were mostly lacking. No conclusions could be drawn in a third of studies. Most others provided evidence consistent with reduction of MRSA acquisition. Six long interrupted time series provided the strongest evidence. Four of these provided evidence that intensive control measures which included patient isolation were effective in controlling MRSA. In two others IW use failed to prevent endemic MRSA. There was no robust economic evaluation. Models showed that improving the detection rate or ensuring adequate isolation capacity reduced endemic levels, with substantial savings achievable. CONCLUSIONS: Major methodological weaknesses and inadequate reporting in published research mean that many plausible alternative explanations for reductions in MRSA acquisition associated with interventions cannot be excluded. No well-designed studies allow the role of isolation measures alone to be assessed. Nonetheless, there is evidence that concerted efforts that include isolation can reduce MRSA even when endemic. Little evidence was found to suggest that current isolation measures recommended in the UK are ineffective, and these should continue to be applied until further research establishes otherwise. The studies with the strongest evidence, together with the results of the modelling, provide testable hypotheses for future research. Guidelines to facilitate design of future research are produced.

A comparison between single-dose fosfomycin trometamol (Monuril) and a 5-day course of trimethoprim in the treatment of uncomplicated lower urinary tract infection in women.

This study is a comparison of the microbiological and clinical efficacy of single-dose fosfomycin trometamol therapy and a 5 day course of trimethoprim in the treatment of uncomplicated urinary tract infection in female patients. Urine dip-slide samples were obtained from 547 female patients aged 18-65 by 22 General Practitioners (GPs) participating in the study from 21 centres in the UK. All patients were diagnosed as having a urinary tract infection by their GP on the basis of history and clinical examination. Patients were randomised to receive either single dose fosfomycin trometamol or a 5 day course of trimethoprim in a 2:1 ratio. Patients who had significant bacteriuria (> or = 10(5) c.f.u/ml) at the first visit (300) were included in the microbiological analysis. The two commonest urinary pathogens isolated were Escherichia coli and Staphylococcus saprophyticus. Trimethoprim resistance was more frequent amongst E. coli isolates whereas fosfomycin trometamol resistance was more common amongst S. saprophyticus isolates. Microbiological cure was demonstrated in 83.3% of the trimethoprim treated group and 83% of the fosfomycin trometamol treated group. Persistence of the infecting bacteria was seen in 17% of each treatment arm.

Methicillin-resistant Staphylococcus aureus (MRSA)--a re-appraisal of control measures in the light of changing circumstances.

Methicillin-resistant Staphylococcus aureus (MRSA) remains an important nosocomial pathogen and the number of affected patients is rising. Increasing numbers of patients at risk of acquisition, inadequate isolation facilities, problems in identifying the source of outbreaks and the perception amongst some clinical colleagues that control measures are too disruptive have contributed to the problems faced by infection control teams. Recent controlled studies indicate that MRSA is no less virulent than sensitive strains and emphasize the continuing need for control measures even where MRSA is endemic. Efforts to control spread should be targeted to key clinical areas, such as intensive care units, where the impact of infection is likely to be greatest, whilst general infection control measures should be strengthened throughout the hospital.

Silicone oil as a reservoir for nosocomial infection.

Two episodes of infection with epidemic methicillin-resistant Staphylococcus aureus (EMRSA) associated with silicone oil baths are described. In vitro studies indicated that certain organisms, including EMRSA, can survive in silicone oil for several days. We conclude that the oil acted as a reservoir for continuing infection in our patients. We suggest routine care of silicone oil baths in order to prevent cross infection.

Methicillin-resistant Staphylococcus aureus: report of an outbreak in a London teaching hospital.

An outbreak with a strain of methicillin-resistant Staphylococcus aureus began in The London Hospital in 1982 and continues to be associated with significant morbidity and mortality. This particular strain, termed epidemic methicillin-resistant S. aureus, is recognized by its characteristic antibiogram, phage-type and plasmid profile. In this outbreak various means of control have been attempted. Sideroom isolation did not curtail spread of the organism and containment was only achieved with the combination of extended screening, mupirocin for treatment of carriage and the use of an isolation ward.

The international spread of methicillin-resistant Staphylococcus aureus.

A genetic analysis of representative methicillin-resistant Staphylococcus aureus (MRSA) being isolated in London and Dublin hospitals has demonstrated that the epidemic strains from two London hospitals are different from the Dublin strains, but indistinguishable from the epidemic strains of eastern Australia. The possibility that some strains of MRSA are more likely than others to spread within hospitals is discussed.

The community prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in older people living in their own homes: implications for treatment, screening and surveillance in the UK.

Methicillin-resistant Staphylococcus aureus (MRSA) predominantly affects those over 65 years old. There may be a substantial pool of older people with MRSA in the community. We studied the prevalence in one London general practice, screening 258 older people living in their own home. MRSA (E-MRSA 15) was found in two participants (0.78%). Past history of MRSA was the only significant risk factor. The results of this and other studies suggest that national guidelines recommending early discharge for MRSA carriers have not resulted in widespread community acquisition amongst elderly people living in their own home. Community antibiotic policies for skin and soft-tissue infection do not require amendment. Patients with previous MRSA should be isolated and screened on admission especially to high-risk units.

Oral PowderJect: a novel system for administering local anaesthetic to the oral mucosa.

OBJECTIVE: To assess the feasibility of using an Oral PowderJect (OPJ) to safely deliver a dose of dry powdered anaesthetic to the oral mucosa, producing an analgesic effect. DESIGN: Single centre: Part 1. An open, non-randomised safety study to check for mucosal damage; Part 2. A double blind sham controlled study to test the anaesthetic effect. SETTING: General practice. SUBJECTS: Adult, healthy volunteers (4 male, 10 female). MATERIALS AND METHODS: Part 1. An OPJ was used to deliver powdered lidocaine hydrochloride to the mucosal surface which was then checked visually for damage. Part 2. An OPJ containing lidocaine hydrochloride (active) or an empty OPJ (sham) was fired at the oral mucosa. The treated area and an untreated (control) site were probed with the back end of a dental needle. RESULTS: The OPJ delivery caused no visible mucosal damage. The median VAS score for pain on blunt probing was 10 for the OPJ active sites. This was significantly lower than the median VAS score for the sham sites at 30 (P = 0.0033) and the control sites at 58 (P < 0.0001). CONCLUSIONS: The OPJ can safely deliver powdered lidocaine hydrochloride to the oral mucosa without causing tissue damage. The OPJ delivery of powdered lidocaine hydrochloride can significantly reduce the pain from a blunt needle probe at 1 minute post delivery.

Gross hematuria as a presenting symptom of disseminated gonorrhea.

I report a case of disseminated gonorrhea which presented with macrohematuria, a heretofore unreported occurrence. Because of associated symptoms, this patient was at first thought to be suffering from a nephrotic syndrome.