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Henning Rüden

Publications and source records attributed to Henning Rüden.

18 recordsLinked to original sources
PubMed2006

The influence of high-efficiency particulate air filtration on mortality and fungal infection among highly immunosuppressed patients: a systematic review.

BACKGROUND: Patients with hematological malignancies who are treated with intensive chemotherapy or who receive bone marrow transplants are exposed to an increased risk of developing nosocomial fungal infections. The aim of this systematic review was to compare the effectiveness of high-efficiency particulate air (HEPA) filtration with that of non-HEPA filtration in decreasing the rates of mortality and fungal infection among patients with diagnosed hematological malignancies and neutropenia or among patients with bone marrow transplants. METHODS: Articles identified in a Medline search, guidelines, and books, as well as the bibliographies of review articles, monographs, and the articles identified by Medline, were researched. Randomized trials and observational studies comparing HEPA filtration with conventional room ventilation were selected for inclusion in the present review. RESULTS: Sixteen trials (9 with death as an outcome and 10 with fungal infection as an outcome) that compared HEPA filtration with non-HEPA filtration were selected for meta-analyses. We discovered no significant advantages of HEPA filtration in the prevention of death among patients with hematological malignancies with severe neutropenia in randomized controlled trials (RCTs; relative risk [RR], 0.86 [95% confidence interval {CI}, 0.65-1.14]) and in studies of a lower standard (non-RCTs; RR, 0.87 [95% CI, 0.60-1.25]). CONCLUSIONS: The placement in protected areas of patients with hematological malignancies with severe neutropenia or patients with bone marrow transplants appears to be beneficial, but no definitive conclusion could be drawn from the data available.

Air Microbiology↗
PubMed2006

Where should one search when confronted with outbreaks of nosocomial infection?

The outbreak database (http://www.outbreak-database.com), containing 1561 records of nosocomial outbreaks published in the medical literature in a systematic format, was used to identify the most frequent outbreak sources for the entire database as well as for specific outbreak pathogens. Overall, in 37.1%, no source was identified. The main sources identified were index patients (40.3%), followed by equipment and devices (21.1%), environment (19.8%), and personnel (15.8%).

Cross Infection↗
PubMed2006

Evaluation of six agglutination tests for Staphylococcus aureus identification depending upon local prevalence of meticillin-resistant S. aureus (MRSA).

Most routine laboratory detection of Staphylococcus aureus isolates is based on rapid agglutination test systems. Failure of agglutination assays to identify meticillin-resistant S. aureus strains (MRSA) has been demonstrated. The aim of this study was to evaluate six commercially available agglutination tests for the detection of meticillin-sensitive S. aureus (MSSA) and mecA-positive MRSA strains. The Dry Spot Staphytect Plus test (Oxoid), the Pastorex Staph Plus test (Bio-Rad), the Slidex Staph-Kit and Slidex Staph Plus test (bioMérieux), the Staphaurex Plus test (Remel) and the Staphylase Test (Oxoid) were used. As determined by pulsed field gel electrophoresis, 52 distinct MRSA strains from five countries, 83 MSSA strains and 150 coagulase-negative staphylococci were included. Species identification and determination of susceptibility patterns were performed using colony morphology, Gram stain, catalase testing, tube coagulase testing, DNase testing, mannitol fermentation, susceptibility testing towards oxacillin by Etest, coagulase gene PCR, fibrinogen receptor gene PCR and PCR of the mecA gene. Sensitivity of the agglutination tests ranged from 82.7 to 100.0 % for MRSA strains and 92.8 to 100.0 % for MSSA strains, respectively. Specificity of the test systems ranged from 91.3 to 99.1 %. None of the six agglutination assays produced correct reactions for all staphylococci tested. Only the Dry Spot Staphytect Plus test correctly identified all 52 MRSA strains. For the other tests kits, sensitivity of MRSA detection was lower than for MSSA isolates. Depending upon the local MRSA prevalence and the parameter of interest (sensitivity or specificity), these test systems may be useful for routine diagnostic purposes.

Anti-Bacterial Agents↗
PubMed2005

The burden of MRSA in four German university hospitals.

In the last few years, a dramatic increase of Methicillin-resistant Staphylococcus aureus (MRSA) detection in German hospitals can be recognized. Under this enormous pressure it is very important for infection control teams to assess the epidemiologic situation correctly. Therefore, a prospective multicenter hospital-based surveillance of MRSA cases was executed in four university hospitals with 1017-1333 beds in Germany. Routine surveillance data were recorded of all patients with MRSA isolates from clinical samples or screening cultures. Patients had been colonized or infected with MRSA during their hospital stay. In 2002 between 183 and 291 MRSA cases were treated in the respective hospitals (between 0.53 and 0.96 MRSA cases per 1000 patient days). Of these, 44.4% were MRSA infections. The most frequent type of MRSA infections were wound infections (56.9%) followed by pneumonia (21.0%) and bloodstream infections (15.1%). Of the infected patients 51.5% were already infected at admission. The median duration of isolation of MRSA patients in private rooms was between 11 and 16 days. Altogether 21,665 isolation days were observed in four hospitals; this means 1.52% of all patient days. On average, 9.0% of roommates were identified as MRSA carriers. Due to the high percentage of imported cases, the four university hospitals introduced a general screening for MRSA at admission in all ICUs and some further departments as well as an automatic alert system for readmitted patient with MRSA during their last hospital stay.

Carrier State↗
PubMed2005

AMBU-KISS: quality control in ambulatory surgery.

BACKGROUND: Cost-containment measures have led to a constant increase in the number of patients cared for as outpatients. Several studies have demonstrated that surgical site infections result in considerable morbidity and excess health care costs from extended duration of hospitalization and antibiotic use. OBJECTIVE: AMBU-KISS is a protocol designed to create a reference database on surgical site infections for institutions involved in ambulatory surgery. METHODS: This study was carried out using a physician questionnaire. We compared surgical site infection rates for 3 indicator procedures in the ambulatory setting to those observed in the inpatient setting. The 3 indicator procedures chosen for the protocol were arthroscopic knee surgery and inguinal hernia and vein-stripping procedures. RESULTS: The arithmetic mean values of surgical site infection rates in arthroscopic surgery of the knee are 0.09% in the ambulatory setting and 0.11% in the hospital setting. For inguinal hernias, the respective rates are 0.65% and 0.78%. These differences, however, did not reach statistical significance (arthroscopic surgery, P = .8323 and inguinal herniotomies, P = .4895). A marked difference was observed for vein-stripping procedures, with surgical site infection rates of 0.38% in the ambulatory setting and 0.64% in the hospital setting. However, this difference was also not statistically significant, P = .1556. CONCLUSION: The AMBU-KISS protocol appears to be suitable for assessing and defining the magnitude of surgical site infections in ambulatory surgery. The preliminary results of our study show no significant differences for the 3 indicator procedures.

Ambulatory Surgical Procedures↗
PubMed2005

How outbreaks can contribute to prevention of nosocomial infection: analysis of 1,022 outbreaks.

OBJECTIVE: To describe the epidemiology of nosocomial outbreaks published in the scientific literature. DESIGN: Descriptive information was obtained from a sample of 1,022 published nosocomial outbreaks from 1966 to 2002. METHODS: Published nosocomial outbreaks of the most important nosocomial pathogens were included in the database. A structured questionnaire was devised to extract information in a systematic manner on nosocomial outbreaks published in the literature. The following items were used: the reference, type of study (case reports or studies applying epidemiologic or fingerprinting methods), type of microorganism, setting, patients and personnel involved, type of infection, source of infection, mode of transmission, risk factors identified, and preventive measures applied. RESULTS: Bloodstream infection was the most frequently identified type of infection (37.0%), followed by gastrointestinal infection (28.5%) and pneumonia (22.9%). In 37% of the outbreaks, the authors were not able to identify the sources. The most frequent sources were patients (25.7%), followed by medical equipment or devices (11.9%), the environment (11.6%), and the staff (10.9%). The mode of transmission remained unclear in 28.3% of the outbreaks. Transmission was by contact in 45.3%, by invasive technique in 16.1%, and through the air in 15.0%. The percentage of outbreaks investigated by case-control studies or cohort studies over the years was small (21% and 9%, respectively, for the whole time period). CONCLUSION: Outbreak reports in the literature are a valuable resource and should be used for educational purposes as well as for preparing outbreak investigations.

Adolescent↗
PubMed2005

How many infections are caused by patient-to-patient transmission in intensive care units?

OBJECTIVE: The proportion of intensive care unit (ICU)-acquired infections that are a consequence of nosocomial cross-transmission between patients in tertiary ICUs is unknown. Such information would be useful for the implementation of appropriate infection control measures. DESIGN: A prospective cohort study during 18 months. SETTING: Five ICUs from two university hospitals. PATIENTS: All patients admitted for >/=48 hrs. MEASUREMENT: ICU-acquired infections were ascertained during daily bedside patient and chart reviews. Episodes of potential cross-transmission were identified by highly discriminating genetic typing of all clinical and surveillance isolates of the ten bacterial species most frequently associated with nosocomial infections in ICUs. Isolation of indistinguishable isolates in two or more patients defined potential transmission episodes. MAIN RESULTS: During 28,498 patient days, 431 ICU-acquired infections and 141 episodes of nosocomial transmissions were identified. A total of 278 infections were caused by the ten species that were genotyped, and 41 of these (14.5%) could be associated with transmissions between patients. CONCLUSION: Infections acquired during treatment in modern tertiary ICUs are common, but a causative role of direct patient-to-patient transmission can only be ascertained for a minority of these infections on the basis of routine microbiological investigations.

Bacterial Infections↗
PubMed2004

To isolate or not to isolate? Analysis of data from the German Nosocomial Infection Surveillance System regarding the placement of patients with methicillin-resistant Staphylococcus aureus in private rooms in intensive care units.

OBJECTIVE: To investigate whether isolating patients with MRSA in private rooms in ICUs (or cohorting) is a protective factor for nosocomial MRSA infection. DESIGN: Association between nosocomial MRSA infection rates and ICU structure and process parameters in the German Nosocomial Infection Surveillance System (KISS). SETTING: Two hundred twelve ICUs participating in KISS in 2001. METHODS: In June 2001, a structured questionnaire was sent to the participating ICUs regarding their preventive measures, their type and size, their patient-to-personnel ratios, and routine cultures. Univariate and multivariate analyses were conducted to identify risk factors for nosocomial MRSA infection. RESULTS: The questionnaire was completed by 164 (77.4%) of the ICUs. These ICUs had 325 nosocomial MRSA infections in a 5-year period (1997 to 2001). The mean incidence density of nosocomial MRSA infections was 0.3/1,000 patient-days. Ninety-one ICUs (55.5%) did not register any nosocomial MRSA infections during the observation period. Forty-two ICUs had an incidence density of at least 0.3/1,000 patient-days (75th percentile). Surgical ICUs were found to be a risk factor for a nosocomial MRSA infection rate above this threshold. Multivariate analysis found surgical ICUs to be an independent predictor and isolation in private rooms (or cohorts) to be a protective factor (OR, 0.36; CI95, 0.17-0.79). CONCLUSION: Many (34.4%) of the German ICUs have not isolated MRSA patients in private rooms or cohorts, a procedure associated with lower MRSA infection rates in this study.

Cross Infection↗
PubMed2004

Finding a method for optimizing risk adjustment when comparing surgical-site infection rates.

OBJECTIVE: To investigate whether stratification of the risk of developing a surgical-site infection (SSI) is improved when a logistic regression model is used to weight the risk factors for each procedure category individually instead of the modified NNIS System risk index. DESIGN AND SETTING: The German Nosocomial Infection Surveillance System, based on NNIS System methodology, has 273 acute care surgical departments participating voluntarily. Data on 9 procedure categories were included (214,271 operations). METHODS: For each of the procedure categories, the significant risk factors from the available data (NNIS System risk index variables of ASA score, wound class, duration of operation, and endoscope use, as well as gender and age) were identified by multiple logistic regression analyses with stepwise variable selection. The area under the receiver operating characteristic (ROC) curve resulting from these analyses was used to evaluate the predictive power of logistic regression models. RESULTS: For most procedures, at least two of the three variables contributing to the NNIS System risk index were shown to be independent risk factors (appendectomy, knee arthroscopy, cholecystectomy, colon surgery, herniorrhaphy, hip prosthesis, knee prosthesis, and vascular surgery). The predictive power of logistic regression models (including age and gender, when appropriate) was low (between 0.55 and 0.71) and for most procedures only slightly better than that of the NNIS System risk index. CONCLUSION: Without the inclusion of additional procedure-specific variables, logistic regression models do not improve the comparison of SSI rates from various hospitals.

Adult↗
PubMed2003

[Surveillance of nosocomial infections in intensive care units. Current data and interpretations].

The German nosocomial infections surveillance system KISS was established in 1996 using a surveillance protocol based on the National Nosocomial Infections Surveillance (NNIS) System. Meanwhile data from a total of 274 intensive care units (ICU) are available, among them 134 interdisciplinary, 71 surgical, 55 medical, 9 neurosurgical and 5 paediatric ICUs. The data comprise about 6,966 surveillance months with more than 500,000 intensive care patients and more than 1.8 million patient days. A total of 6,888 cases of pneumonia and 2,357 cases of central venous catheter (CVC) associated primary bloodstream infections (BSI) were recorded. Ventilator associated pneumonia rates and CVC associated primary BSI rates are presented, stratified according to the type of the ICU and affiliation to a university, a teaching hospital or another type of hospital. The most frequent pathogens associated with ventilator associated pneumonia were S. aureus (24.1%), followed by P. aeruginosa (16.8%) and Klebsiella spp. (12.1%). In the case of CVC associated primary BSI coagulase negative staphylococci dominated (30.9%) followed by S. aureus (15.4%) and Enterococci spp. (11.6%). A remarkable increase of Methicillin Resistant Staphylococcus aureus (MRSA) infections was observed during the period from 1997 to 2002. 19.2% of S. aureus associated pneumonia cases and 25.5% of S. aureus associated primary BSI were due to MRSA. KISS data are useful benchmarks for internal quality management, however a careful interpretation is necessary to stimulate infection control efforts.

Adult↗
PubMed2003

The relationship between methodological trial quality and the effects of impregnated central venous catheters.

OBJECTIVE: We assessed the methodological trial quality of individual randomized controlled studies on chlorhexidine silver sulfadiazine impregnated catheters and the effect on catheter-related infection (CRI). DESIGN: Only the studies identified in the Medline database from 1966 to December 2001 were considered, abstracts being excluded. The outcome of this investigation centered on bloodstream CRI. The trial quality of the 11 studies identified and published (total 3,131 catheters) was assessed using a scoring system based on allocation, patient selection, patient characteristics, blinding of the intervention and the diagnosis of CRI (range 0-2 points, 10 points maximum). RESULTS: The mean methodological quality score was 7.1 (range 5-9). The relative risk reduction for bloodstream CRI ranged from -0.14 to 1.0. No association between trial quality and the impact of chlorhexidine silver sulfadiazine impregnated catheters on CRI was found. The summary odds ratio for CRI was 0.69 (95% CI 0.46-1.03). Taking only those studies with 2 points for diagnosis of CRI a summary odds ratio of 0.87 (95% CI 0.44-1.72) resulted, whereas studies with a diagnosis score of only 1 point led to a summary odds ratio of 0.60 (95% CI 0.35-1.02). CONCLUSIONS: The quality of the studies seems to have had no influence on the outcome, according to the results of this investigation, but the use of only a single quality score may not be sufficient to investigate the prevention effect of impregnated catheters.

Anti-Infective Agents, Local↗
PubMed2003

Five years working with the German nosocomial infection surveillance system (Krankenhaus Infektions Surveillance System).

A national surveillance system for nosocomial infections, Krankenhaus Infektions Surveillance System (KISS), was established in Germany as a joint effort by the National Reference Center for Hospital Epidemiology (currently called the National Reference Center for the Surveillance of Nosocomial Infections) and the Robert Koch Institute. To begin with a well-accepted and proven method, surveillance protocols were developed on the basis of the National Nosocomial Infections Surveillance system. Hospitals from all parts of Germany took part voluntarily. There were 4 surveillance components: intensive care departments (227), patients undergoing operation (231 departments), neonatal intensive care departments (23 hospitals), and patients undergoing bone marrow and peripheral blood stem cell transplants (10 hospitals). Five years after the introduction of KISS many hospitals have introduced continuous surveillance activities whereby the various definitions and methods have attained wide acceptance. This has lead to much better understanding and cooperation between clinicians and infection control personnel in preventing nosocomial infections. KISS is considered the national reference database, but continuous evaluation and development of KISS are necessary to react adequately.

Cross Infection↗
PubMed2003

A cluster of nosocomial Klebsiella pneumoniae bloodstream infections in a neonatal intensive care department: Identification of transmission and intervention.

OBJECTIVE: We sought to determine the cause and mode of transmission of a cluster of bloodstream infections as a result of Klebsiella pneumoniae. DESIGN AND SETTING: We conducted a prospective cohort study in a neonatal intensive care department from May 1999 to December 2000. METHODS: We performed surveillance of nosocomial infections, and clinical and environmental investigations. RESULTS: During an 8-week period, 5 cases of K pneumoniae bloodstream infections were observed, at least 3 of them belonging to the same genotype. Before the second case developed any symptoms of infection, the same strain had also been found in the patient environment. Intervention measures were, therefore, immediately introduced. Further cases, however, occurred in the following weeks. Even after further intervention activities and the end of the outbreak, the same strain was discovered in environmental samples from a stethoscope and a nurse's hand. CONCLUSIONS: Even where there is acute awareness of the problem and a generally high infection control level in a department, it is difficult to change behavior in such a way that further nosocomial infections can be totally excluded.

Bacteremia↗
PubMed2003

Reducing central venous catheter-associated primary bloodstream infections in intensive care units is possible: data from the German nosocomial infection surveillance system.

BACKGROUND AND OBJECTIVE: The German Nosocomial Infection Surveillance System (KISS) began in 1997 as a nationwide surveillance project for voluntary registration of nosocomial infections in intensive care units (ICUs). This study investigates trends in the rates of central venous catheter (CVC)-associated primary bloodstream infections (BSIs) in ICUs since participation in KISS. METHODS: Eighty-four ICUs that had participated in KISS for at least 24 months were considered for more detailed analysis. Monthly rates of primary BSI for the 84 ICUs were pooled for the 24 months. The best model for describing the curve of reduction was sought. Additionally, incidence densities were compared using the z test. RESULTS: For the 212 ICUs participating, a relative 25.7% decrease (from 2.1 to 1.6 primary BSIs per 1,000 CVC-days) was observed from January 1997 to June 2001. The 84 ICUs that participated in KISS for a minimum of 24 months accumulated 552,359 patient-days and 404,897 CVC-days during their 24 months. A linear regression model was selected to explain the curve of primary BSI reduction in the 84 ICUs. It showed a decrease from 2.1 to 1.5 primary BSIs per 1,000 CVC-days, meaning an overall relative reduction of 28.6% during the 2-year observation period. These results were significant (Student's t test for the monthly reduction coefficient; P = .04). The reduction of primary BSIs was shown for both clinical sepsis and laboratory-confirmed, CVC-associated primary BSIs. CONCLUSION: Performing surveillance with KISS was associated with a reduction of the rates of CVC-associated primary BSIs in ICU patients.

Catheterization, Central Venous↗
PubMed2002

A quality management project in 8 selected hospitals to reduce nosocomial infections: a prospective, controlled study.

OBJECTIVE: To reduce the number of nosocomial infections (NIs) in surgical patients by a quality management approach. DESIGN: Prospective, controlled study in 8 medium-sized hospitals during a 26-month period. SETTING: Four study hospitals and 4 control hospitals. METHODS: In two 10-month intervention periods, 4 external physicians introduced quality circles and ongoing surveillance in the 4 study hospitals. There were three 8-week observation periods in all 8 hospitals with the same physicians before, during, and after the intervention periods. RESULTS: During the first observation period, almost identical overall incidence densities were found for the study hospitals and the control hospitals. During the course of the study, the overall incidence density decreased significantly in the study hospitals (risk ratio [RR], 0.74; 95% confidence interval [CI 95], 0.59 to 0.94) and nonsignificantly in the control hospitals (RR, 0.90; CI 95 0.70 to 1.16). With the use of a Cox regression model to evaluate the impact of the intervention periods while taking into account the distribution of risk factors for NI in both groups, a significant risk reduction (RR, 0.75; CI 95, 0.58 to 0.97) was observed after the first intervention period when comparing study and control hospitals. At the end of the study (ie, after the second intervention period), the difference between the study hospitals and the control hospitals was not significant (RR, 0.78; CI 95, 0.60 to 1.01). This was due to no further improvement at the end of the study in the study hospitals and a decrease in the control hospitals. CONCLUSION: This study demonstrates that NI rates can be significantly reduced by appropriate intervention methods in hospitals that are interested in quality management activities. However, continuous intense efforts are necessary to maintain these improvements.

Aged↗
PubMed2002

How many nosocomial infections are associated with cross-transmission? A prospective cohort study in a surgical intensive care unit.

OBJECTIVE: To determine the percentage of cross-transmissions in an intensive care unit (ICU) with high nosocomial infection (NI) rates according to the data of the German Nosocomial Infection Surveillance System. SETTING: A 14-bed surgical ICU of a 1,300-bed, tertiary-care teaching hospital. METHOD: Prospective surveillance of NIs during a period of 9 months. If an NI was present, the isolates of the following indicator pathogens were stored and typed by species: Staphylococcus aureus, Enterococcus species, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterobacter species. Pulsed-field gel electrophoresis was performed for typing of S. aureus strains and arbitrarily primed polymerase chain reaction was applied for the other pathogens. The presence of two indistinguishable strains in two patients was considered as one episode of cross-transmission. RESULTS: Two hundred sixty-two patients were observed during a period of 2,444 patient-days; 96 NIs were identified in 59 patients and the overall incidence density of NI was 39.3 per 1,000 patient-days. For 104 isolates, it was possible to consider typing results. Altogether, 36 cross-transmissions have lead to NIs in other patients. That means at least 37.5% of all NIs identified were due to cross-transmissions. CONCLUSION: Because of the method of this study, the percentage of NIs due to cross-transmission identified for this ICU is an "at least number." In reality, the number of cross-transmissions, and thus the number of avoidable infections, may have been even higher. However, it is difficult to assess whether the percentage of NIs due to cross-transmission determined for this ICU may be the crucial explanation for the relatively high infection rate in comparison to other surgical ICUs.

Bacteria↗