Walter Koller

Clinical Impact of Antimicrobial Resistance in European Hospitals: Excess Mortality and Length of Hospital Stay Related to Methicillin-Resistant Staphylococcus aureus Bloodstream Infections

ABSTRACT Antimicrobial resistance is threatening the successful management of nosocomial infections worldwide. Despite the therapeutic limitations imposed by methicillin-resistant Staphylococcus aureus (MRSA), its clinical impact is still debated. The objective of this study was to estimate the excess mortality and length of hospital stay (LOS) associated with MRSA bloodstream infections (BSI) in European hospitals. Between July 2007 and June 2008, a multicenter, prospective, parallel matched-cohort study was carried out in 13 tertiary care hospitals in as many European countries. Cohort I consisted of patients with MRSA BSI and cohort II of patients with methicillin-susceptible S. aureus (MSSA) BSI. The patients in both cohorts were matched for LOS prior to the onset of BSI with patients free of the respective BSI. Cohort I consisted of 248 MRSA patients and 453 controls and cohort II of 618 MSSA patients and 1,170 controls. Compared to the controls, MRSA patients had higher 30-day mortality (adjusted odds ratio [aOR] = 4.4) and higher hospital mortality (adjusted hazard ratio [aHR] = 3.5). Their excess LOS was 9.2 days. MSSA patients also had higher 30-day (aOR = 2.4) and hospital (aHR = 3.1) mortality and an excess LOS of 8.6 days. When the outcomes from the two cohorts were compared, an effect attributable to methicillin resistance was found for 30-day mortality (OR = 1.8; P = 0.04), but not for hospital mortality (HR = 1.1; P = 0.63) or LOS (difference = 0.6 days; P = 0.96). Irrespective of methicillin susceptibility, S. aureus BSI has a significant impact on morbidity and mortality. In addition, MRSA BSI leads to a fatal outcome more frequently than MSSA BSI. Infection control efforts in hospitals should aim to contain infections caused by both resistant and susceptible S. aureus.

Burden of antimicrobial resistance in European hospitals: excess mortality and length of hospital stay associated with bloodstream infections due to Escherichia coli resistant to third-generation cephalosporins

OBJECTIVES This study determined excess mortality and length of hospital stay (LOS) attributable to bloodstream infection (BSI) caused by third-generation-cephalosporin-resistant Escherichia coli in Europe. METHODS A prospective parallel matched cohort design was used. Cohort I consisted of patients with third-generation-cephalosporin-resistant E. coli BSI (REC) and cohort II consisted of patients with third-generation-cephalosporin-susceptible E. coli BSI (SEC). Patients in both cohorts were matched for LOS before infection with patients free of the respective BSI. Thirteen European tertiary care centres participated between July 2007 and June 2008. RESULTS Cohort I consisted of 111 REC patients and 204 controls and cohort II consisted of 1110 SEC patients and 2084 controls. REC patients had a higher mortality at 30 days (adjusted odds ratio = 4.6) and a higher hospital mortality (adjusted hazard ratio = 5.7) than their controls. LOS was increased by 8 days. For SEC patients, these figures were adjusted odds ratio = 1.9, adjusted hazard ratio = 2.0 and excess LOS = 3 days. A 2.5 times [95% confidence interval (95% CI) 0.9-6.8] increase in all-cause mortality at 30 days and a 2.9 times (95% CI 1.2-6.9) increase in mortality during entire hospital stay as well as an excess LOS of 5 days (95% CI 0.4-10.2) could be attributed to resistance to third-generation cephalosporins in E. coli BSI. CONCLUSIONS Morbidity and mortality attributable to third-generation-cephalosporin-resistant E. coli BSI is significant. If prevailing resistance trends continue, high societal and economic costs can be expected. Better management of infections caused by resistant E. coli is becoming essential.

Closed Suctioning System Reduces Cross-Contamination Between Bronchial System and Gastric Juices

In this prospective, randomized study, we evaluated whether a closed suctioning (CS) system (TrachCare) influences crossover contamination between bronchial system and gastric juices when compared with an open suctioning system (OS). The secondary aims were an analysis of the frequency of ventilator-associated pneumonia (VAP) and an analysis of alteration in gas exchange. Antibiograms were performed from tracheal secretions and gastric juice aspirates on Days 1 and 3 of intubation in 24 patients in a medical intensive care unit. Five cross-contaminations were observed in the OS group on Day 3 versus Day 1; the 5 strains shared common genotypes as determined by random amplification of polymorphic DNA. No cross-contaminations were seen in the CS group (P = 0.037). VAP occurred in 5 patients of the OS group but in none of the CS group patients (P = 0.037). Spao(2) decreased significantly in the OS group compared with presuctioning values--the opposite of the CS group. Whereas presuctioning values were comparable between groups, postsuctioning Spao(2) was significantly higher in the CS group. CS significantly reduced cross-contamination between bronchial system and gastric juices and reduced the incidence of VAP when compared with OS. Hypoxic phases can be reduced by the help of CS.

Evaluation of the decontamination efficacy of new and reprocessed microfiber cleaning cloth compared with other commonly used cleaning cloths in the hospital.

BACKGROUND The aim of this study was to investigate the decontamination capacity of 4 different types of cleaning cloths (microfiber cleaning cloth, cotton cloth, sponge cloth, and disposable paper towels) commonly used in hospital in their ability to reduce microbial loads from a surface used dry or wet in new condition. All of the cloths except disposable paper towels were also compared after 10 and 20 times of reprocessing, respectively, at 90 degrees C for 5 minutes in a washing machine. METHODS Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 8739) were used as test organisms. Test organisms were then added to a test soil (6% bovine serum albumin and 0.6% sheep erythrocytes) resulting in a controlled concentration of 5 x 10(7) colony-forming units per milliliter in the final test suspension. Standardized tiles measuring 5 x 5 cm were used as test surface. RESULTS Microfiber cloths showed the best results when being used in new condition. However, after multiple reprocessing, cotton cloth showed the best overall efficacy. CONCLUSION We therefore suggest that the choice of the cleaning utilities should be based on their decontamination efficacy after several reprocessings and recommend the establishment of strict and well-defined cleaning and disinfection protocols.

Effectiveness of an automated surveillance system for intensive care unit-acquired infections

This study assessed the effectiveness of a fully automated surveillance system for the detection of healthcare-associated infections (HCAIs) in intensive care units. Manual ward surveillance (MS) and electronic surveillance (ES) were performed for two intensive care units of the Vienna General Hospital. All patients admitted for a period longer than 48 h between 13 November 2006 and 7 February 2007 were evaluated according to HELICS-defined rules for HCAI. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and personnel time spent per surveillance type were calculated. Ninety-three patient admissions were observed, whereby 30 HCAI episodes were taken as a reference standard. Results with MS versus ES were: sensitivity 40% versus 87%, specificity 94% versus 99%, PPV 71% versus 96%, NPV 80% versus 95%, and time spent per surveillance type 82.5 h versus 12.5 h. In conclusion, ES was found to be more effective than MS while consuming fewer personnel resources.

Fuzzy-Based Nosocomial Infection Control

Nosocomial, or hospital-acquired, infections (NIs) are a frequent complication affecting hospitalized patients. The growing availability of computerized patient records in hospitals allows automated identification and extended monitoring of the signs of NI for the purpose of reducing NI rates. A fuzzy- and knowledge-based system to identify and monitor NIs at intensive care units according to the European Surveillance System HELICS was developed. It was implemented into the information technology landscape of the Vienna General Hospital and is now in routine use.

A simple hand hygiene exercise

In an illustrative sequence of exercises, we teach our students how to don, use, and take off sterile gloves correctly and how to wash hands properly. During this sequence, the effect of a good handwashing technique as well as the effect of failures in aseptic technique with gloves is made directly visible by the use of finger paints. This technique helps medical staff to visualize microbial contamination of the hands and to increase the awareness of breaks in aseptic technique.

Concordance between European and US case definitions of healthcare-associated infections

BackgroundSurveillance of healthcare-associated infections (HAI) is a valuable measure to decrease infection rates. Across Europe, inter-country comparisons of HAI rates seem limited because some countries use US definitions from the US Centers for Disease Control and Prevention (CDC/NHSN) while other countries use European definitions from the Hospitals in Europe Link for Infection Control through Surveillance (HELICS/IPSE) project. In this study, we analyzed the concordance between US and European definitions of HAI.MethodsAn international working group of experts from seven European countries was set up to identify differences between US and European definitions and then conduct surveillance using both sets of definitions during a three-month period (March 1st -May 31st, 2010). Concordance between case definitions was estimated with Cohen’s kappa statistic (κ).ResultsDifferences in HAI definitions were found for bloodstream infection (BSI), pneumonia (PN), urinary tract infection (UTI) and the two key terms “intensive care unit (ICU)-acquired infection” and “mechanical ventilation”. Concordance was analyzed for these definitions and key terms with the exception of UTI. Surveillance was performed in 47 ICUs and 6,506 patients were assessed. One hundred and eighty PN and 123 BSI cases were identified. When all PN cases were considered, concordance for PN was κ = 0.99 [CI 95%: 0.98-1.00]. When PN cases were divided into subgroups, concordance was κ = 0.90 (CI 95%: 0.86-0.94) for clinically defined PN and κ = 0.72 (CI 95%: 0.63-0.82) for microbiologically defined PN. Concordance for BSI was κ = 0.73 [CI 95%: 0.66-0.80]. However, BSI cases secondary to another infection site (42% of all BSI cases) are excluded when using US definitions and concordance for BSI was κ = 1.00 when only primary BSI cases, i.e. Europe-defined BSI with ”catheter” or “unknown” origin and US-defined laboratory-confirmed BSI (LCBI), were considered.ConclusionsOur study showed an excellent concordance between US and European definitions of PN and primary BSI. PN and primary BSI rates of countries using either US or European definitions can be compared if the points highlighted in this study are taken into account.

Re-evaluation of current A0 value recommendations for thermal disinfection of reusable human waste containers based on new experimental data

Issues over the correct cleaning and disinfection of reusable medical devices are of great concern for local infection control teams. We investigated the heat resistance of two important micro-organisms implicated in nosocomial infections, Enterococcus spp. and spores of Bacillus subtilis (a surrogate for Clostridium difficile). Disinfection with moist heat, based on the A(0) concept (EN ISO 15883-1), is the most common method for disinfection of human waste containers in the hospital setting. The aim of this study was to scrutinise the A(0) concept regarding the inactivation of the above-mentioned micro-organisms and to look for possible interferences. Experiments were carried out in phosphate-buffered saline, artificial soil in suspension (ASS) and dried artificial soil (AS). Artificial soil was used to simulate insufficient cleaning of bedpans. Micro-organisms were treated at different temperatures and time periods. It was shown that soil protected the micro-organisms against heat and that dried soil enhanced this effect, probably as a result of thermal insulation. The results of the current study do not support the general recommendation to use an A(0) of 60 for the disinfection of bedpans but warrant differential strategies depending on the expected microbial load. We generally recommend for disinfection processes aimed at vegetative bacteria an A(0) of >or=180. Furthermore we want to emphasise the utmost importance of not allowing freshly contaminated bedpans to dry for longer time periods, as the significance of thorough cleaning of contaminated human waste containers before being exposed to heat treatment for their disinfection was clearly demonstrated.

Effectiveness of preventive measures for hemato-oncologic patients undergoing stem cell transplantation during a period of hospital construction

BACKGROUND Aspergillus spp are ubiquitous spore-forming fungi. Construction work, renovation, demolition, or excavation activities within a hospital or in surrounding areas increase the risk for aspergillus infection in susceptible patients and are the main cause of nosocomial aspergillus outbreaks. METHODS We investigated the efficacy of infection control measures on the frequency of fungal infection among hemato-oncologic patients undergoing stem cell transplantation during excavation and construction work of an adjacent hospital building. Clinical isolates from these patients obtained before and during the excavation and construction period were analyzed. Preventive measures consisted in the implementation of a multibarrier concept to protect these patients from fungal infection. RESULTS There was no record of any clinical isolate of Aspergillus spp in the observation period before the beginning of the groundwork. However, 3 clinically significant isolates of Aspergillus spp were detected in respiratory tract specimen of 2 patients after the beginning of excavation and demolition work, which were found to be community acquired. CONCLUSION Although our data cannot demonstrate the efficacy of infection control measures during construction work, it can be concluded that excavation work close to immunocompromised patients is safe if a bundle of preventive measures is implemented before groundwork.