Knowledge of Clostridium difficile infection among UK health-care workers: development of a knowledge assessment tool.

Doctors' knowledge provides the basis to support good practice in infection prevention and control. However, there exists a paucity of validated knowledge assessment tools that can be reliably employed to identify poor knowledge levels of Clostridium difficile infection (CDI) within populations of doctors, preventing the effective identification of knowledge deficiencies and focused targeting of educational interventions. Here, we describe a development process to validate a novel CDI knowledge assessment tool for doctors. Two previously published CDI knowledge questionnaires were amalgamated to produce a combined questionnaire. Content was further evaluated by a panel of CDI experts, producing the 'Lothian' questionnaire. These questionnaires were tested in control populations comprising either infection control nurse (ICN) specialists or non-clinically trained individuals, and a cohort of medical staff. We compared the efficacy of the 'Lothian' questionnaire against that of previous questionnaire reports. We found that all of the questionnaires studied significantly discriminated between non-clinical and clinical populations (ICNs and medical staff) (P < 0.001) and had similar levels of sensitivity and specificity in discrimination between these targeted populations. This study describes the development of a robust CDI knowledge assessment tool that can be used to evaluate knowledge levels among doctors, compare populations and assist the targeting of educational interventions and plot trends following such interventions.

A prevalence screen of MRSA nasal colonisation amongst UK doctors in a non-clinical environment.

Screening for methicillin-resistant Staphylococcus aureus (MRSA) carriage in healthcare workers (HCWs) is both contentious and confounded by a lack of knowledge of background prevalence rates. This study examines prevalence of nasal MRSA carriage amongst a spectrum of medical professionals in a non-clinical environment. Medical conference attendees volunteered for screening for nasal MRSA carriage, and anonymised demographic data and attitudes towards screening were recorded. Two hundred sixty volunteers participated. One hundred seventy-three participants (67%) were from the British Medical Association's Annual Representatives Meeting, and 87 participants (33%) were attending the Association of Surgeons in Training conference. Six (2%) participants were positive for MRSA nasal carriage (BMA = 1%, ASIT = 5%; p = 0.099). Participants from a surgical specialty (4.8%) were more likely to be MRSA positive (p = 0.039). All positive samples came from male participants (p = 0.182). However, there was no significant association with gender, seniority or country of employment and MRSA status. Routine screening for MRSA was supported by 63% of participants in HCWs; 36% had previously undergone such screening. MRSA nasal carriage rates within this cross-sectional study are lower than studies reporting carriage rates in HCWs within the clinical environment. Further research is required to examine the relationship between MRSA nasal colonisation status of a HCW and subsequent MRSA infection in patients.

A cluster of deep bacterial infections following eye surgery associated with construction dust.

SUMMARY: Three cases of serious eye infection (two endophthalmitis, one orbital cellulitis; two caused by Staphylococcus aureus, one caused by viridans streptococci) occurred shortly after surgery (two cataracts, one retinal detachment repair) within two weeks. There had been construction work adjacent to the theatres during this time, and fine dust was found on horizontal surfaces. Further surgery was cancelled, the construction work was completed and theatres were cleaned before recommencing with no further infections. Following a review of factors that may be involved in the pathogenesis of endophthalmitis, it is proposed that the mechanism of infection in these cases may have been due to the presence of foreign material enhancing the pathogenicity of the small numbers of organisms often found in intra-ocular fluids during surgery. This hypothesis could be tested in experimental models of endophthalmitis.

How much time is needed for hand hygiene in intensive care? A prospective trained observer study of rates of contact between healthcare workers and intensive care patients.

There are few data measuring rates of contact by healthcare workers (HCWs) with intensive care unit (ICU) patients (direct contacts) and their immediate environment (indirect contacts), or estimates of the time needed for 100% hand hygiene compliance. We measured this using a prospective trained observer study in a 12-bedded UK adult general ICU admitting > 600 mixed medical/surgical patients annually. HCWs were observed in ICU bed spaces for 1-h periods by a single researcher using a pre-determined plan, such that all 12 beds were observed for similar times and throughout the day. Mean daily rates of direct and indirect contact between HCWs and ICU patients were calculated. Observed post-contact hand hygiene compliance was also measured. Numbers of contacts/day that were or were not followed by hand hygiene, and estimates of the time needed daily for 100% compliance were calculated. On average, each patient was contacted directly 159 [95% confidence intervals (CI) 144-178] times and contacted indirectly 191 (95% CI 174-210) times/day. Observed post-contact hand hygiene rates were 43% for direct contacts and 12% for indirect contacts. Staff contacting more than one patient during routine care, who carry the highest risk of transmitting infection between patients, made, on average, 22 direct and 107 indirect contacts without adequate hand hygiene/patient/day. One hundred percent hand hygiene compliance by all healthcare workers would require about 230 min/patient/day (100 min for direct and 130 min for indirect contacts).

Antibiotic prescription practice in an intensive care unit using twice-weekly collection of screening specimens: a prospective audit in a large UK teaching hospital.

Controversy exists regarding the optimal method of managing intensive care unit (ICU)-acquired infection. Antibiotic prescriptions in 177 sequential admissions to our ICU, which collected twice-weekly screening samples, were audited. Seventy-seven percent of patients received at least one antibiotic prescription, and 45% of patients received at least one prescription for suspected or proven sepsis. Of the 353 antibiotic prescriptions audited, 86 were prophylactic and 61 were first prescribed prior to ICU admission. One hundred and eighty-three were prescribed for sepsis; of these, 108 (59%) were empirical prescriptions and only 21% of these were subsequently changed. For the 75 prescriptions for specific organisms, 28% targeted organisms isolated at least four days previously. Clinicians in our ICU reviewed the data and reached consensus that screening was associated with decision making that did not represent current evidence-based practice, because empirical prescriptions were rarely changed or stopped on the basis of new samples, and those prescribed for confirmed infection frequently targeted organisms isolated before the septic episode. After our audit, we stopped regular collection of screening samples and used more targeted and invasive sampling, in response to clinical suspicion, to guide therapy and maintain data concerning local microbial epidemiology.

Serological investigation into the association between Streptococcus bovis and colonic cancer.

AIMS: To determine if there was an increase in antibody titre to Streptococcus bovis in patients with colonic cancer, and if this might be a useful marker of the presence for colonic cancer. METHODS: Serum samples from 16 patients and 16 age matched controls were tested by immunoblot and enzyme linked immunosorbent assay (ELISA) against antigen preparations from two strains of S bovis and one strain of Enterococcus faecalis. RESULTS: No distinction between cancer patients and controls could be made using immunoblots. ELISA did show an increase in antibodies to S bovis, but there was a greater increase in antibodies to E faecalis. The increase in antibody titres was greatest with antigens which had been treated with periodate, and was therefore thought not to be caused by antibody to the shared group D carbohydrate antigen. CONCLUSION: It may be possible to construct a test for the detection of colonic cancer based on the detection of antibody to S bovis or E faecalis, though considerable further development of this concept is required.

Urinary IgG antibody against mixed heat-killed coliform antigen and lipopolysaccharide core antigen.

AIMS: To determine whether antibody to lipopolysaccharide-core (LPS-core) antigen is an important component of the antibody, detected by mixed heat-killed coliform antigen, in urine from patients with suspected urinary tract infection. METHODS: LPS-core antigen and mixed heat-killed coliform antigen were used in an enzyme linked immunosorbent assay (ELISA) to measure IgG antibody in midstream urine samples. Seventy two samples from students attending their general practitioner with symptoms suggestive of urinary tract infection, six samples from which a Gram positive organism was isolated, and 16 asymptomatic controls were tested. Plates coated with LPS-core antigen were also used to absorb out the antibody detected by the mixed heat-killed coliform antigen. RESULTS: Antibody to either antigen was associated with a positive culture, but neither was a useful predictor of a positive culture. There was a significant correlation between the results of the two assays (r = 0.7633; p less than 0.001), and absorption with LPS-core antigen did reduce the level of antibody to the mixed heat-killed coliform antigen. Antibody to both preparations was found in patients with Gram positive urinary tract infection. CONCLUSION: Antibody to LPS-core antigen forms a substantial part of the antibody detected by mixed heat-killed coliform ELISA. The antibodies detected by these assays are probably the result of non-specific leakage of antibody into the urine, rather than a specific immune response.

Failure to kill Yersinia enterocolitica by plasma diluted to the concentration found in red cell units.

The possibility that the use of additive solutions for red cell storage might impair the ability of plasma to kill Yersinia enterocolitica was investigated by studying killing of Y enterocolitica by neat and diluted plasma. The ability of neat citrated plasma to kill complement sensitive organisms was lost at around 26%, the dilution typically found in red cell units. These results should be considered in the light of evidence that killing in plasma is important in the protection of donated blood against growth of Y enterocolitica, and the observation that the increase in frequency of transfusion reactions caused by Y enterocolitica coincided with the widespread introduction of additive solutions. Taken together, these points support the suggestion that the introduction of additive solutions may have precipitated the problem of growth of Y enterocolitica in stored blood.

Rate of growth of Pseudomonas fluorescens in donated blood.

AIMS: To examine how delayed refrigeration of blood affects the growth of Pseudomonas fluorescens, one of the two most important causes of sepsis resulting from transfusion of contaminated blood. METHODS: Two donations of whole blood were each divided into three aliquots and inoculated with 5-10 cfu/ml of a P fluorescens strain from a case of transfusion associated sepsis. From each donation, one aliquot was placed at 4 degrees C, one was held at 20 degrees C for six hours prior to refrigeration and the third was held at 20 degrees C for 24 hours prior to refrigeration. Samples were aseptically withdrawn over 17 days and bacterial counts were determined using a pour plate technique. RESULTS: The rate of growth of P fluorescens in blood at 20 degrees C was increased compared with blood at 4 degrees C. At 24 hours the aliquots held at 20 degrees C for six and 24 hours had, respectively, 174 and 29,000 cfu/ml compared with 15 cfu/ml in aliquots held at 4 degrees C. There was no evidence of increased killing of P fluorescens at the higher temperature. CONCLUSIONS: These results suggest that blood for transfusion should be refrigerated as soon as possible after collection.

Cefpodoxime screening of Escherichia coli and Klebsiella spp. by Vitek for detection of organisms producing extended-spectrum beta-lactamases.

We used a Vitek custom card to detect cefpodoxime MIC of--2 mg/L as a screen for extended-spectrum beta-lactamase (ESBL) production in E. coli and Klebsiella spp. Of 2873 organisms tested, 60 were screen positive, but only 3 were confirmed to be ESBL producers. Cefpodoxime is believed to be a sensitive screen for ESBL production, but a more specific test is desirable.

Comparative study of BacT/Alert FAN bottles and standard BacT/Alert bottles.

A total of 5,230 paired blood cultures were studied. One sample was divided between aerobic and anaerobic BacT/Alert standard bottles, and the other divided between aerobic and anaerobic BacT/Alert FAN bottles. There were 44 occasions where Staphylococcus aureus was recovered only from the FAN bottles, compared to six where only the standard bottles were positive (p < 0.001), and 21 occasions where Escherichia coli was isolated only from FAN bottles, compared to eight occasions where only the standard bottles were positive for this organism (p < 0.05). In 21 of 28 cases reviewed where S. aureus was isolated from FAN bottles only the patient had been receiving anti-staphylococcal antibiotics. However, only 2 of 30 cases where Gram-negative bacilli were isolated from FAN bottles had documented recent appropriate antibiotic therapy. Patients in whom FAN bottles are more likely to recover organisms cannot be selected on the basis of documented antibiotic treatment.

Successful treatment of Prototheca peritonitis complicating continuous ambulatory peritoneal dialysis.

We describe the second reported case of peritonitis caused by the alga Prototheca wickerhamii in a patient on continuous ambulatory peritoneal dialysis (CAPD). This organism, which grows slowly on agar media, is recognised as a race cause of other infections. The condition is clinically similar to cases of fungal peritonitis, but there are important differences, particularly when choosing the best treatment.

Reduction in blood culture contamination rate by feedback to phlebotomists.

OBJECTIVE: To determine whether monitoring and feedback of blood culture contamination rates to phlebotomists would reduce the overall contamination rate. DESIGN: Before and after interventional study. SETTING: Blood cultures collected by venipuncture by phlebotomists at Foothills Hospital, Calgary, a tertiary care teaching hospital. INTERVENTION: Feedback of contamination rates calculated from a laboratory definition of blood culture contamination. The definition was based on isolation of typical skin organisms from a single blood sample when two samples were obtained. MAIN OUTCOME MEASURE: Reduction in the laboratory-defined contamination rate in the second year. RESULTS: Of 8462 cultures collected by phlebotomists in the prefeedback year, 224 (2.6%) were contaminated, compared to 131 (1.4%) of 9282 cultures in the postfeedback year. There was a rise in the total number of positive cultures regarded as significant but a fall in the number of coagulase-negative staphylococci that were regarded as significant by our definition. The rate of contamination in blood cultures collected by nonphlebotomists did not change. CONCLUSIONS: The contamination rate decreased after feedback. Our definition of contamination was imperfect and could be improved, but it was valuable in achieving a real reduction in blood culture contamination.

No increase in frequency of antifungal resistance among yeasts isolated from normally sterile sites in patients at Foothills Hospital from 1993 to 1996.

OBJECTIVE: To determine the prevalence of resistance to antifungal drugs among yeasts isolated from sterile sites from patients in one hospital and the relationship of resistance to antifungal use, and to assess whether resistance was increasing. METHOD: Susceptibility testing performed by National Committee for Clinical Laboratory Standards (NCCLS) (Villanova, Pennsylvania) microdilution method and by E test. Antifungal use was determined by selected chart review and from pharmacy data. SPECIMENS AND SETTING: Tertiary care adult hospital with neonatal intensive care. POPULATION STUDIED: Distinct yeast isolates from sterile site specimens collected during the years 1993 to 1996. RESULTS: A total of 132 yeast isolates were studied, of which 78 (59%) were Candida albicans. The proportion of C albicans remained steady over the four-year period, and there was no trend to increased resistance among C albicans. The number of isolates of all species with fluconazole microdilution minimum inhibitory concentration (MIC) greater than 8 mg/L in each of the four years were one of 32 in 1996, three of 26 in 1994, six of 33 in 1995, and one of 41 in 1996. A single isolate had an itraconazole microdilution MIC greater than 0.5 mg/L in each year. Prior use of antifungal therapy was rare in this patient population. CONCLUSIONS: The increase in resistance to antifungal drugs reported by some centres did not occur in this institution over the course of the study. This experience may reflect differences in infection control practices and in patterns of use of antifungal agents. The NCCLS method was found to be superior to the E test as a routine method for testing susceptibility of yeasts.

Empyema caused by Clostridium difficile.

Extraintestinal infections of Clostridium difficile are rare and often associated with underlying disorders. A case of empyema caused by aspiration of C difficile in a patient with carcinoid syndrome and C difficile colitis is described.

Mobile phone technology and hospitalized patients: a cross-sectional surveillance study of bacterial colonization, and patient opinions and behaviours.

Healthcare workers' mobile phones provide a reservoir of bacteria known to cause nosocomial infections. UK National Health Service restrictions on the utilization of mobile phones within hospitals have been relaxed; however, utilization of these devices by inpatients and the risk of cross-contamination are currently unknown. Here, we examine demographics and characteristics of mobile phone utilization by inpatients and phone surface microbial contamination. One hundred and two out of 145 (70.3%) inpatients who completed a questionnaire detailing their opinions and utilization of mobile phones, also provided their mobile phones for bacteriological analysis and comparative bacteriological swabs from their nasal cavities; 92.4% of patients support utilization of mobile phones by inpatients; indeed, 24.5% of patients stated that mobile phones were vital to their inpatient stay. Patients in younger age categories were more likely to possess a mobile phone both inside and outside hospital (p <0.01) but there was no gender association. Eighty-six out of 102 (84.3%) patients' mobile phone swabs were positive for microbial contamination. Twelve (11.8%) phones grew bacteria known to cause nosocomial infection. Seven (6.9%) phones and 32 (31.4%) nasal swabs demonstrated Staphylococcus aureus contamination. MSSA/MRSA contamination of phones was associated with concomitant nasal colonization. Patient utilization of mobile phones in the clinical setting is popular and common; however, we recommend that patients are educated by clear guidelines and advice on inpatient mobile phone etiquette, power charging safety, regular cleaning of phones and hand hygiene, and advised not to share phones or related equipment with other inpatients in order to prevent transmission of bacteria.