Biomedical subjects
J E Coia
Publications and source records attributed to J E Coia.
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.
Ciprofloxacin resistance in non-typhoidal Salmonella serotypes in Scotland, 1993-2003.
OBJECTIVES: To determine the levels of resistance to ciprofloxacin among non-typhoidal salmonellae in Scotland. METHODS: Etest strips were used to determine the ciprofloxacin MICs for nalidixic acid-resistant salmonellae isolated from humans during 1993-2003. RESULTS: The percentage of nalidixic acid-resistant salmonellae isolated from human infection in Scotland has increased from 1.4% in 1993, to 8.8% in 1998 and 21.3% in 2003. Of 493 strains of nalidixic acid-resistant Salmonella tested, a single isolate of Salmonella Typhimurium RDNC was resistant to ciprofloxacin at the NCCLS breakpoint of 4 mg/L. Eleven isolates were resistant at the Scottish Salmonella Reference Laboratory breakpoint of 0.5 mg/L, while 466 isolates (94.5%) had reduced susceptibility with MICs of > or =0.125 mg/L and <0.5 mg/L. CONCLUSIONS: These results show that very few non-typhoidal isolates of Salmonella in Scotland that are resistant to nalidixic acid are also resistant to ciprofloxacin at the NCCLS recommended breakpoint of 4 mg/L. The majority of isolates examined, however, do show reduced susceptibility at 0.125 mg/L. This confirms the necessity for continuing antimicrobial surveillance of resistance to this important antibiotic.
Investigation of human infections with Salmonella enterica serovar Java in Scotland and possible association with imported poultry.
PFGE analysis of S. Java strains (29 from humans, 30 from poultry meat) showed two major clusters. All isolates from poultry imported from the Netherlands belonged to Cluster A, which also comprised 10 human isolates. Thirty-one of the 37 isolates in this cluster had an identical JavX1 pattern, similar to the X8 profile of a particular S. Java clone predominant in poultry production in several European countries. Cluster B comprised 19 human isolates and two poultry isolates of unknown origin. These results combined with epidemiological data and information on the origins of poultry meat strongly suggested that imported poultry meat is an important source of Java infections in humans in Scotland.
A survey of the prevalence of Escherichia coli O157 in raw meats, raw cow's milk and raw-milk cheeses in south-east Scotland.
2429 samples of foodstuffs were examined for the presence of verocytotoxigenic Escherichia coli O157 (VTEC O157) by means of immunomagnetic separation (IMS) over a 2-year period commencing April 1997. Specimens comprised 1190 raw meats, 500 raw milks and 739 raw-milk cheeses. The meat and cheese samples were purchased from retail premises in south-east Scotland; raw milk samples were obtained directly from farms. In addition, total E. coli counts were performed on milk and cheese samples, and the pH of cheese specimens measured. The water activity (Aw) was also measured for a representative sample of each cheese type, and for all of the samples with high levels of E. coli. VTEC O157 was isolated from two samples of beef burger, both manufactured on the premises of the same butchers shop. Control studies with artificially inoculated foodstuffs demonstrated a sensitivity of detection of < 5 organisms 25 g(-1). These findings, which contrast with the results of similar studies elsewhere in the UK, suggest that other sources of infection may be important in explaining the high rates of infection with this organism in south-east Scotland.
Risk factors for sporadic cases of Escherichia coli O157 infection: the importance of contact with animal excreta.
To determine environmental risk factors for sporadic E. coli O157 infection in Scotland we undertook a prospective, matched case-control study between 1 October 1996 and 31 March 1999. One hundred and eighty-three cases and 545 matched controls were recruited. Contact with animal faeces (OR = 3.65; 95% CI 1.81, 7.34: P < 0.0005) and likely contact with animal faeces (OR = 4.8; 95% CI 2.42, 9.48; P < 0.0005) emerged as strong risk factors for infection. Certain exposures (mainly food-related) were inversely associated with infection i.e. were statistically protective. Most striking was the consumption of bottled water (OR = 0.28; 95% CI 0.15, 0.52; P < 0.0005). Transmission of E. coli O157 does not occur simply through contaminated food. Members of the public need to be aware of the potential for acquiring E. coli O157 through contamination of the environment with animal faeces so that they may take measures to mitigate their risk.
Computer keyboards as a risk for nosocomial infection.
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The diagnostic value of anti-neutrophil cytoplasmic antibody testing in a routine clinical setting.
Anti-neutrophil cytoplasmic antibody (ANCA) tests are a routine clinical assay in most UK hospitals. We examined the role of routine ANCA testing in achieving a diagnosis of systemic vasculitis in a routine clinical setting. From April 1996 to March 2000, 2734 samples from five hospital departments were tested for ANCA by indirect immunofluorescence (IIF) at a single laboratory. After April 1999, enzyme-linked immunosorbent assays (ELISAs) were performed on all IIF-positive samples. Clinical diagnosis was determined for all patients with a positive IIF ANCA, and a sample of the ANCA-negative patients. Some 2-18% of patients with suspected ANCA-associated systemic vasculitis (AASV) had positive IIF ANCA. The AASV diagnosis was confirmed in 0-56% of these cases. Analysis by department suggested that 88-100% of patients with a positive IIF ANCA did not have AASV, except in the Rheumatology department. The positive predictive value (PPV) of IIF ANCA for AASV was 59% and the negative predictive value (NPV) was 84%. Of the patients with proven AASV, 41% did not have ANCA on IIF. Combined ANCA testing by IIF/ELISA had a higher sensitivity and PPV but lower specificity than IIF alone for AASV. For the combined IIF/ELISA test, only the Rheumatology department had a sensitivity or PPV >0% for AASV. The PPV of ANCA by IIF/ELISA for AASV was 79% and the NPV was 63%. The ANCA test is being widely applied with very poor return. Guidelines for more effective usage are proposed.
Eradication of a resistant Pseudomonas aeruginosa strain after a cluster of infections in a hematology/oncology unit.
OBJECTIVES: This report chronicles an outbreak of a multiply resistant strain of Pseudomonas aeruginosa and the measures required to contain this outbreak. METHODS: Laboratory-based ward-liaison surveillance allowed the detection of a multiply resistant strain of P. aeruginosa infecting patients in our hematology/oncology unit. Sampling of the immediate environment was carried out. Pulsed field gel electrophoresis was used to compare the patients' organisms with those found in the environment. Extensive dismantling of the drainage system, repeated cleaning and disinfection, and a review of the departmental antibiotic policy were some of the infection control measures instigated. RESULTS: During a period of 11 months, three patients in the hematology department and two patients in the oncology department were infected with multiply resistant P. aeruginosa. There were two cases of pneumonia, one of which was fatal, and two cases of neutropenic septicaemia. Pulsed field gel electrophoresis performed on the isolates showed that the isolates from geographically separate areas could be divided into two strains that were closely related but distinct. Two genotypically identical strains were also isolated from the plumbing systems in the areas of each ward where patients had been treated. CONCLUSIONS: The potential for serious nosocomial infections with P. aeruginosa is well recognized. Eradication of the organism from the environment may require the co-ordinated efforts of clinicians, nurses, pharmacy and hospital engineers, working in collaboration with the hospital infection control team. To date, the same strains have not been isolated despite repeated surveillance over the past 18 months and therefore these measures have, in our opinion, successfully removed the potential for nosocomial infection with this resistant organism in our hospital.
Mycobacterium chelonae isolated from rinse water within an endoscope washer-disinfector.
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Multi-centre research surveillance project to reduce infections/phlebitis associated with peripheral vascular catheters.
A surveillance project was undertaken on 37 surgical wards by infection control nurses with the aim of reducing phlebitis/infections associated with peripheral vascular catheters, and to identify risk factors. Data on 2934 catheters in situ longer than 24h was collected in two separate surveillance periods and results were fed back after each surveillance period. Four significant risk factors were identified; what the catheters were used for, the duration the catheters were in situ, the surveillance period (the first surveillance period had a higher phlebitis rate than the second) and whether an infusion pump was used. Logistic regression analysis showed that each of these had a significant effect after adjusting for the effects of the other three factors.
Controlling Escherichia coli O157: the emerging challenge.
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Use of bar code readers and programmable keypads to improve the speed and accuracy of manual data entry in the clinical microbiology laboratory: experience of two laboratories.
AIM: To assess the effect of the use of bar code readers and programmable keypads for entry of specimen details and results in two microbiology laboratories. METHODS: The solutions selected in each laboratory are described. The benefits resulting from the implementation were measured in two ways. The speed of data entry and error reduction were measured by observation. A questionnaire was completed by users of bar codes. RESULTS: There were savings in time and in reduced data entry errors. Average time to enter a report by keyboard was 21.1 s v 14.1 s for bar coded results entry. There were no observed errors with the bar code readers but 55 errors with keystroke entries. The laboratory staff of all grades found the system fast, easy to use, and less stressful than conventional keyboard entry. CONCLUSIONS: Indirect time savings should accrue from the observed reduction in incorrectly entered data. Any microbiology laboratory seeking to improve the accuracy and efficiency of data entry into their laboratory information systems should consider the adoption of this technology which can be readily interfaced to existing terminals.
Environmental risk factors for sporadic Escherichia coli O157 infection in Scotland: results of a descriptive epidemiology study.
The objective of the study was to obtain detailed descriptive epidemiological information on sporadic verocytotoxin-producing Escherichia coli O157 infection in Scotland in relation to transmission routes and host-related risk factors. Using a standardized questionnaire, the study was carried out throughout Scotland over an 18-month period from July 1992 and co-ordinated at the Communicable Diseases and Environmental Health (Scotland) Unit, Glasgow (CDEH(S)U). The subjects were laboratory-confirmed cases of Escherichia coli O157 infection, of whom 138 met the criteria for inclusion in the study. The most important findings were the high proportion of cases who had been exposed to environmental factors such as farm animals and/or their by-products; or who had participated in gardening or garden-play; or who had suspected or confirmed household water supply problems, prior to the onset of illness. The frequency and relative importance of environmental risk factors requires further quantification and study in order to assess where control measures can be directed most effectively. The implications for the NHS in preventing this crippling, life-threatening infection are considerable, not least in relation to hospitalization, dialysis and renal transplantation costs.
Nosocomial and laboratory-acquired infection with Escherichia coli O157.
Infections caused by verocytotoxigenic Escherichia coli O157 (VTEC O157) have emerged as a major public health concern. The nature and severity of associated clinical sequelae are such that symptomatic cases often require hospitalization, with possible exposure to other patients and healthcare workers, including laboratory personnel, to the risk of acquiring VTEC O157. The occurrence of such episodes of hospital- and laboratory-acquired infections has demonstrated that these concerns are justified. Hospital infection control teams must ensure that staff are aware of this potential hazard, and laboratories must review their operating procedures to ensure that their personnel are not unnecessarily exposed, particularly in the light of revised guidance on the safe handling of these organisms.
Clinical, microbiological and epidemiological aspects of Escherichia coli O157 infection.
In the last decade infections caused by Escherichia coli O157:H7 and other verocytotoxigenic E. coli (VTEC) have emerged as a major public health concern in North America and in Europe, and increasingly in other areas of the world. Although absolute numbers of infections are low in comparison with other enteric pathogens such as Salmonella or Campylobacter, it is well-recognised that E. coli O157 can produce severe, potentially life-threatening, illness. As a consequence of this awareness, there has been a rapid expansion of our knowledge about these organisms and the diseases which they cause. In this article, the clinical, microbiological and epidemiological features of VTEC O157 infection are reviewed.
A comparison of immunomagnetic separation, direct culture and polymerase chain reaction for the detection of verocytotoxin-producing Escherichia coli O157 in human faeces.
Verocytotoxin-producing Escherichia coli O157 (O157 VTEC) has become well recognized as an important enteric pathogen. The number of organisms present in environmental and clinical samples may be low and efforts have been made to increase the sensitivity of O157 VTEC detection. Immunomagnetic seperation (IMS) has been shown to improve O157 VTEC detection in bovine faeces and food samples. A milkborne outbreak of O157 VTEC infection allowed us to compare the isolation rates from human faeces by IMS, direct faecal culture on sorbitol-MacConkey agar and a PCR test for verotoxin gene carriage. Of 142 faecal samples examined, 20 were positive on both direct culture and IMS and a further 13 on IMS alone. Therefore, IMS increased the detection rate of individual cases of O157 VTEC infection and also compared well with PCR. We recommend IMS for use in routine diagnostic laboratories where a more sensitive method than direct faecal culture is required for O157 VTEC isolation.
Refractory methicillin-resistant Staphylococcus aureus carriage associated with contamination of the home environment.
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