Antimicrobial Resistance and Infection Control - Latest Articles

Carriage of extended-spectrum beta-lactamase-producing enterobacteriacae among internal medicine patients in Switzerland

Janet Pasricha — 2013-06-12T00:00:00Z

Background: The incidence of extended-spectrum beta-lactamase producing-enterobacteriacae (ESBL-E) infection is rising worldwide. We aimed to determine the prevalence and nosocomial acquisition rate of ESBL-E as well as the risk factors for ESBL-E carriage and acquisition amongst patients consecutively admitted to 13 internal medicine units at our hospital who were not previously known to be ESBL-E carriers.FindingsWe screened all patients admitted or transferred to internal medicine units for ESBL-E on admission and discharge using rectal swabs. Of 1072 patients screened, 51 (4.8%) were carriers of an ESBL-E at admission. Of 473 patients who underwent admission and discharge screening, 21 (4.4%) acquired an ESBL-E. On multivariate analysis, diabetes mellitus without end-organ complications (OR 2.8 [1.1-7.1]), connective tissue disease (OR 7.2 [1.2-44.6], and liver failure (OR 8.4 [1.5-45.4]) were independent risk factors for carriage of an ESBL-E upon admission to hospital (area under the ROC curve, 0.68). Receipt of a first- or second-generation cephalosporin (OR 9.25 [2.2-37.8]), intra-hospital transfer (OR 6.7 [1.7-26.1]), and a hospital stay >21 days (OR 25.1 [4.2-151.7]) were associated with acquisition of an ESBL-E during hospitalisation; whilst admission from home was protective (OR 0.16 [0.06-0.39]) on univariate regression. No risk profile with sufficient accuracy to predict previously unknown carriage on admission or acquisition of ESBL-E could be developed using readily available patient information. Conclusions: ESBL-E carriage is endemic amongst internal medicine patients at our institution. We were unable to develop a clinical risk profile to accurately predict ESBL-E carriage amongst these patients.

Efficacy of hand rubs with a low alcohol concentration listed as effective by a national hospital hygiene society in Europe

Günter Kampf — 2013-06-12T00:00:00Z

Background: Some national hospital hygiene societies in Europe such as the French society for hospital hygiene (SFHH) have positive lists of disinfectants. Few hand disinfectants with a rather lowconcentration of ethanol are listed by one society as effectivefor hygienic hand disinfection with 3 mL in 30 s including a virucidal activity in 30 s or 60 s, but published data allowhaving doubts. We have therefore evaluated the efficacy of three commonly used hand disinfectants according to EN 1500 and EN 14476. Methods: Products 1 (Aniosgel 85 NPC) and 2 (Aniosrub 85 NPC) were based on 70% ethanol, product 3 (ClinoGel derma+) on 60% ethanol and 15% isopropanol (all w/w). They were tested in 3laboratories according to EN 1500. Three mL were applied for 30 s and compared to the reference treatment of 2 x 3 mL applications of isopropanol 60% (v/v), on hands artificiallycontaminated with Escherichia coli. Each laboratory used a cross-over design against the reference alcohol with 15 or 20 volunteers. The virucidal activity of the products wasevaluated (EN 14476) in one laboratory against adenovirus and poliovirus in different concentrations (80%, 90%, 97%), with different organic loads (none; clean conditions;phosphate-buffered saline) for up to 3 min. Results: Product 1 revealed a mean log10-reduction of 3.87 +/- 0.79 (laboratory 1) and 4.38 +/- 0.87 (laboratory 2) which was significantly lower compared to the reference procedure (4.62 +/- 0.89 and 5.00 +/- 0.87). In laboratory 3 product 1 was inferior to the reference disinfection (4.06 +/- 0.86 versus 4.99 +/- 0.90). Product 2 revealed similar results. Product 3 fulfilled therequirements in one laboratory but failed in the two other. None of the three products was able to reduce viral infectivity of both adenovirus and poliovirus by 4 log10 steps in 3 minaccording to EN 14476. Conclusions: Efficacy data mentioned in a positive list published by a society for hospital hygiene should still be regarded with caution if they quite obviously contradict published data on the same or similar products.

Eradication of an outbreak of vancomycin-resistant Enterococcus (VRE): the cost of a failure in the systematic screening

Lélia Escaut — 2013-06-06T00:00:00Z

Background: Vancomycin-resistant enterococci (VRE) are still a concern in hospital units tending to seriously ill patients. However, the cost-effectiveness of active surveillance program to identify asymptomatically VRE colonized patient remains debatable. This work aims at evaluating the cost of a failure in the active surveillance of VRE that had resulted in an outbreak in a French University Hospital.FindingsA VRE outbreak was triggered by a failure in the systematic VRE screening in a medico-surgical ward specialised in liver transplantation as a patient was not tested for VRE. This failure was likely caused by the reduction of healthcare resource. The outbreak involved 13 patients. Colonized patients were grouped in a dedicated part of the infectious diseases unit and tended by a dedicated staff. Transmission was halted within two months after discovery of the index case.The direct cost of the outbreak was assessed as the cost of staffing, disposable materials, hygiene procedures, and surveillance cultures.The loss of income from spare isolation beds was computed by difference with the same period in the preceding year. Payments were drawn from the hospital database. The direct cost of the outbreak (2008 Euros) was [euro sign]60 524 and the loss of income reached [euro sign]110 915. Conclusions: Despite this failure, the rapid eradication of the VRE outbreak was a consequence of the rapid isolation of colonized patient. Yet, eradicating even a limited outbreak requires substantial efforts and resources. This underlines that special attention has to be paid to strictly adhere to active surveillance program.

Methicillin-resistant Staphylococcus aureus risk profiling: who are we missing?

Janet Pasricha — 2013-05-30T00:00:00Z

Background: Targeted screening of patients at high risk for methicillin-resistant Staphylococcus aureus (MRSA) carriage is an important component of MRSA control programs, which rely on prediction tools to identify those high-risk patients. Most previous risk studies reported a substantial rate of patients who are eligible for screening, but failed to be enrolled. The characteristics of these missed patients are seldom described. We aimed to determine the rate and characteristics of patients who were missed by a MRSA screening programme at our institution to see how the failure to include these patients might impact the accuracy of clinical prediction tools.FindingsFrom March-June 2010 all patients admitted to 13 internal medicine wards at the University of Geneva Hospital (HUG) were prospectively screened for MRSA carriage. Of 1968 patients admitted to the ward, 267 patients (13.6%) failed to undergo appropriate MRSA screening. Forty-one (2.4%) screened patients were MRSA carriers at admission. On multivariate regression, patients who were missed by screening were more likely to be aged < 50 years (OR 2.4 [1.4-3.9]), transferred to internal medicine from another ward in the hospital (OR 2.8 [1.1-7.1]), and have a history of malignancy (OR 3.2[2.1-5.1]). There was no significant difference in the rate of previous MRSA carriage between screened and unscreened patients. Conclusions: Our findings highlight the potential bias that “missed” patients may introduce into MRSA risk scores. Reporting on the proportions and characteristics of missed patients is essential for accurate interpretation of MRSA prediction tools.

A novel approach to improve hand hygiene compliance of student nurses

Sharon Salmon — 2013-05-30T00:00:00Z

Background: The National University Hospital, Singapore routinely undertakes standardized Hand Hygiene auditing with results produced by ward and by staff type. In 2010 concern was raised over consistently low compliance by nursing students averaging 45% (95% CI 42%–48%) prompting us to explore novel approaches to educating our next generation of nurses to improve their hand hygiene practice.We introduced an experiential learning assignment to final year student nurses on attachment to NUH inclusive of hand hygiene auditor training followed by a period of hand hygiene observation. The training was based on the World Health Organisation (WHO) “My 5 moments for hand hygiene” approach. Upon completion students completed an anonymous questionnaire to evaluate their learning experience.FindingsBy 2012, nursing students were 40% (RR: 1.4, 95% CI 1.3–1.5, p<0.001) more likely to comply with hand hygiene practices. 97.5% (359/368) of nursing students felt that the experience would enhance their own hand hygiene practice and would recommend participating in audits as a learning instrument. Conclusions: With consideration of all stakeholders a sustainable, flexible, programme was implemented. Experiential learning of hand hygiene was a highly valued educational tool and in our project was directly associated with improved hand hygiene compliance. Feedback demonstrated popularity amongst participants and success in achieving its program objectives. While this does not guarantee long term behavioural change it is intuitive that instilling good habits and messages at the early stages of a career will potentially have significant long-term impact.

Implementation of the world health organization hand hygiene improvement strategy in critical care units

Waleed Mazi — 2013-05-14T00:00:00Z

Background: To determine hand hygiene compliance before and after an intervention campaign in critical care units, this study was carried out in the Intensive care unit (ICU), Neonatal intensive care unit (NICU), Burns unit (BU) and the Kidney unit of the King Abdul Aziz Specialist Hospital, Taif, Saudi Arabia. The observation using the WHO hand hygiene protocol took place in four phases with phase I, between April 24-May 06 2010 and phase II from May 29-June 09 2010. An educational intervention took place between the Phases I and II. Follow-up Phases III and IV were from 01–15 October 2010 and 15–30 March 2011 respectively.Findings1,975 hand hygiene opportunities comprising of 409 in Phase I, 406 in Phase II, 620 in Phase III and 540 Phase IV were observed. Compliance rate was 67% pre-intervention, 81% in phase II, declining to 59% and 65% in phases III and IV. Increased compliance in the ICU from 39% in Phase I to 81% in Phase IV (p < 0.05) was sustained throughout the study. Highest compliance rates were recorded among nurses in all phases. The improved compliance for physicians observed in the post-intervention phase was lost in follow-up phases. Missed opportunities for hand hygiene were before patient contact, after touching patient’s surrounding and before aseptic techniques. Team-work and leadership were identified as enhancing factors for compliance. Conclusion: The WHO hand hygiene strategy combined with health education, continuous evaluation and team approach resulted in increased compliance but this was not sustained in certain critical care areas.

Reviewer Acknowledgement 2012

Andreas Voss — 2013-04-12T00:00:00Z

Contributing reviewersAntimicrobial Resistance and Infection Control would like to thank the following colleagues for their assistance with peer review of manuscripts for the journal in 2012.

Antimicrobial susceptibility profiles of human and piglet Clostridium difficile PCR-ribotype 078

Elisabeth Keessen — 2013-04-08T00:00:00Z

In the last decade, outbreaks of nosocomial Clostridium difficile infections (CDI) occurred worldwide. A new emerging type, PCR-ribotype 027, was the associated pathogen. Antimicrobial susceptibility profiles of this type were extensively investigated and used to partly explain its spread. In Europe, the incidence of C. difficile PCR-ribotype 078 recently increased in humans and piglets. Using recommendations of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical and Laboratory Standards Institute (CLSI) we studied the antimicrobial susceptibility to eight antimicrobials, mechanisms of resistance and the relation with previously prescribed antimicrobials in human (n=49) and porcine (n=50) type 078 isolates. Human and porcine type 078 isolates showed similar antimicrobial susceptibility patterns for the antimicrobials tested. In total, 37% of the isolates were resistant to four or more antimicrobial agents. The majority of the human and porcine isolates were susceptible to amoxicillin (100%), tetracycline (100%) and clindamycin (96%) and resistant to ciprofloxacin (96%). More variation was found for resistance patterns to erythromycin (76% in human and 59% in porcine isolates), imipenem (29% in human and 50% in porcine isolates) and moxifloxacin (16% for both human and porcine isolates). MIC values of cefuroxim were high (MICs >256 mg/L) in 96% of the isolates. Resistance to moxifloxacin and clindamycin was associated with a gyr(A) mutation and the presence of the erm(B) gene, respectively. A large proportion (96%) of the erythromycin resistant isolates did not carry the erm(B) gene. The use of ciprofloxacin (humans) and enrofloxacin (pigs) was significantly associated with isolation of moxifloxacin resistant isolates. Increased fluoroquinolone use could have contributed to the spread of C. difficile type 078.

Difficult-to-detect carbapenem-resistant IMP13-producing P. aeruginosa: experience feedback concerning a cluster of urinary tract infections at a surgical clinic in France

Odile Milan — 2013-04-04T00:00:00Z

Background: We report a carbapenem-resistant P. aeruginosa clone responsible for a cluster of urinary tract infections in elderly surgery patients, diagnosed during a three-month period in a 59-bed surgical clinic.FindingsThe clonal nature of the cluster was established by molecular study of the P. aeruginosa isolates (PFGE and MLST). Despite an MIC of imipenem in the susceptibility range for two isolates, all were metallo-β-lactamase-producers (IMP13-type, clone ST621). We conducted a review of the medical and surgical procedures. We tested water delivered into the clinic and urological devices for the presence of the epidemic strain. The hygiene nurse observed hygiene practices. A week after the implementation of barrier precautions around the fourth infected patient, we studied the extent to which the patients hospitalised were colonised to assess whether the spread of the epidemic strain had been controlled. Conclusions: 1/ Our findings indicate the difficulties in the detection of the metallo-β-lactamase in this clone, that resulted in the alert being delayed. 2/ Unlike most investigations of UTI outbreaks described in urology wards, we did not detect any contaminated urological devices or water colonisation. 3/ Consistent with outbreaks involving the IMP-13 clone in critical care units, the observation of inadequate application of standard precautions argued for patient-to-patient transmission during urinary management of the urology patients. 4/ The implementation of barrier precautions around infected patients resulted in control of the spread of the epidemic clone. This report serves as an alert concerning a difficult-to-detect multidrug-resistant P. aeruginosa clone in elderly urology patients.

The impact of staffing on central venous catheter-associated bloodstream infections in preterm neonates ¿ results of nation-wide cohort study in Germany

Rasmus Leistner — 2013-04-04T00:00:00Z

Background: Very low birthweight (VLBW) newborns on neonatal intensive care units (NICU) are at increased risk for developing central venous catheter-associated bloodstream infections (CVC BSI). In addition to the established intrinsic risk factors of VLBW newborns, it is still not clear which process and structure parameters within NICUs influence the prevalence of CVC BSI. Methods: The study population consisted of VLBW newborns from NICUs that participated in the German nosocomial infection surveillance system for preterm infants (NEO-KISS) from January 2008 to June 2009. Structure and process parameters of NICUs were obtained by a questionnaire-based enquiry. Patient based date and the occurrence of BSI derived from the NEO-KISS database. The association between the requested parameters and the occurrance of CVC BSI and laboratory-confirmed BSI was analyzed by generalized estimating equations. Results: We analyzed data on 5,586 VLBW infants from 108 NICUs and found 954 BSI cases in 847 infants. Of all BSI cases, 414 (43%) were CVC-associated. The pooled incidence density of CVC BSI was 8.3 per 1,000 CVC days. The pooled CVC utilization ratio was 24.3 CVC-days per 100 patient days. A low realized staffing rate lead to an increased risk of CVC BSI (OR 1.47; p=0.008) and also of laboratory-confirmed CVC BSI (OR 1.78; p=0.028). Conclusions: Our findings show that low levels of realized staffing are associated with increased rates of CVC BSI on NICUs. Further studies are necessary to determine a threshold that should not be undercut.