German Nosocomial Infection Surveillance System Research Articles

Sinks in patient rooms in ICUs are associated with higher rates of hospital-acquired infection: a retrospective analysis of 552 ICUs

Sinks in hospitals are a possible reservoir for healthcare-related pathogens. They have been identified as a source of nosocomial outbreaks in intensive care units (ICU); however, their role in non-outbreak settings remains unclear. To investigate whether sinks in ICU patient rooms are associated with a higher incidence of hospital-acquired infection (HAI). This analysis used surveillance data from the ICU component of the German nosocomial infection surveillance system (KISS) from 2017 to 2020. Between September and October 2021, all participating ICUs were surveyed about the presence of sinks in their patient rooms. The ICUs were then divided into two groups: the no-sink group (NSG) and the sink group (SG). Primary and secondary outcomes were total HAIs and HAIs associated with Pseudomonas aeruginosa (HAI-PA). In total, 552 ICUs (NSG N=80, SG N=472) provided data about sinks, total HAIs and HAI-PA. The incidence density per 1000 patient-days of total HAIs was higher in ICUs in the SG (3.97 vs 3.2). The incidence density of HAI-PA was also higher in the SG (0.43 vs 0.34). The risk of HAIs associated with all pathogens [incidence rate ratio (IRR)=1.24, 95% confidence interval (CI) 1.03-1.50] and the risk of lower respiratory tract infections associated with P.aeruginosa (IRR=1.44, 95% CI 1.10-1.90) were higher in ICUs with sinks in patient rooms. After adjusting for confounders, sinks were found to be an independent risk factor for HAI (adjusted IRR 1.21, 95% CI 1.01-1.45). Sinks in patient rooms are associated with a higher number of HAIs per patient-day in the ICU. This should be considered when planning new ICUs or renovating existing ones.

Inadequate Timing Limits the Benefit of Antenatal Corticosteroids on Neonatal Outcome: Retrospective Analysis of a High-Risk Cohort of Preterm Infants in a Tertiary Center in Germany.

Introduction A common problem in the treatment of threatened preterm birth is the timing and the unrestricted use of antenatal corticosteroids (ACS). This study was performed to evaluate the independent effects of the distinct timing of antenatal corticosteroids on neonatal outcome parameters in a cohort of very low (VLBW; 1000 – 1500 g) and extreme low birth weight infants (ELBW; < 1000 g). We hypothesize that a prolonged ACS-to-delivery interval leads to an increase in respiratory complications. Materials and Methods Main data source was the prospectively collected single center data for the German nosocomial infection surveillance system (KISS) between 2015 and 2018. Multivariate regression analysis was performed to determine independent effects of the ACS-to-delivery interval on the need for ventilation, surfactant or the occurrence of bronchopulmonary dysplasia, neonatal sepsis or necrotizing enterocolitis. Subgroup analysis was performed for ELBW and VLBW neonates. Results A total of 239 neonates were included. We demonstrate a significantly increased risk of respiratory distress characterized by the need for ventilation (OR 1.045; CI 1.011 – 1.080) and surfactant administration (OR 1.050, CI 1.018 – 1.083) depending on the ACS-to-delivery interval irrespective of other confounders. Every additional day between ACS and delivery increased the risk for ventilation by 4.5% and for surfactant administration by 5%. Subgroup analysis revealed significant differences of respiratory complications in VLBW infants. Conclusions Our data strongly support the deliberate use and timing of antenatal corticosteroids in pregnancies with threatened preterm birth versus a liberal strategy. When given more than 7 days before birth, each day between application and delivery increases is relevant concerning major effects on the infant. Especially VLBW preterm neonates benefit from optimal timing.

Increase in surgical site infections caused by gram-negative bacteria in warmer temperatures: Results from a retrospective observational study.

Surgical site infections (SSIs) occur more frequently during periods of warmer temperatures. We aimed to investigate for which pathogens this association is particularly strong. A retrospective observational study was conducted. Data from the SSI-module of the German nosocomial infection surveillance system between 2000 and 2016 were linked with data from the German Meteorological Service. Patient- and procedure-related data were associated with monthly aggregated meteorological data. Due to high correlation with other meteorological parameters, we focused on the outside temperature. Adjusted odds ratios were calculated for SSI rates relating to temperature. SSIs were stratified by pathogen. A P value of <.05 was considered significant. Altogether, 2,004,793 procedures resulting in 32,118 SSIs were included. Generally, warmer temperatures were associated with a higher SSI risk, especially for SSIs with gram-negative pathogens. This association was particularly prominent for Acinetobacter spp, Pseudomonas aeruginosa, and certain Enterobacteriaceae. Per additional 1°C, we observed a 6% increase in the SSI risk for Acinetobacter spp and a 4% increase for Enterobacter spp. Superficial SSIs with Acinetobacter spp were 10 times more likely to occur when comparing surgeries in months with mean temperatures of ≥20°C to mean temperatures of <5°C. Higher temperatures were associated with increased SSI rates caused by gram-negative bacteria. Future SSI prevention measures should consider this aspect. Underlying shifts in microbiome composition due to climate factors should be included in further analyses. Given the expected rise of global temperatures until the end of the century, this topic has relevance from multiple perspectives.

Increase in Surgical Site Infections Caused by Gram-Negative Pathogens in Warmer Weathers Data From More Than 2 Million Surgeries

Background: Various studies have linked periods of warmer temperatures to an increased occurrence of surgical site infections (SSIs) and healthcare-associated infections in general. In an observational study, we sought to determine the pathogens for which this association was especially strong. Method: Patient- and procedure-related data of the SSI-module of the German nosocomial infection surveillance system were linked with monthly aggregated meteorological data from the German Meteorological Service for a period from 2000 to 2016. Due to high correlation with other meteorological parameters, analyses were executed focusing on the outside ambient temperature. Temperature was regarded as both a continuous variable and a categorical variable with different temperature intervals (5°C steps ranging from &lt;5°C to ≥20°C). Through multivariable logistic regression analysis, adjusted odds ratios (OR) with 95% confidence intervals were calculated for SSI rates relating to temperature. SSIs were stratified by pathogen and depth of infiltration. Result: Altogether, 2,004,793 procedures, conducted in 1,455 German surgical departments and resulting in 32,118 SSIs, were included. A general association of warmer mean temperatures in the month of surgery with an increased SSI-risk was observed, particularly for SSIs caused by gram-negative pathogens. Stratification by pathogen revealed that the association was especially prominent for Acinetobacter spp, Pseudomonas aeruginosa, and certain Enterobacteriaceae. Per additional 1°C, we observed a 6% increase in the risk for SSIs caused by Acinetobacter spp (OR, 1.06; 95% CI, 1.04–1.09), and a 4% increase in the risk for SSIs caused by Enterobacter spp (OR, 1.04; 95% CI, 1.03–1.05). Among gram-positive pathogens, temperature-association was strongest for Staphylococcus aureus. Superficial SSIs showed a higher temperature-association than deeper SSIs. The risk for superficial SSIs with Acinetobacter spp significantly increased &gt;10-fold after surgeries conducted in months with a mean temperature of ≥20°C in reference to &lt;5°C. For Pseudomonas aeruginosa, we observed a &gt;2-fold statistically significant increase in the risk for superficial SSIs, when comparing the same temperature categories (≥20°C vs &lt;5°C). Conclusions: Our study demonstrated that higher temperatures were associated with increased SSI-rates caused by gram-negative bacteria. As a consequence, future SSI-prevention measures should place a higher emphasis on the parameter season as part of a more tailormade, personalized approach at infection prevention. For instance, it may be conceivable to seasonally adjust decolonizing regimes and certain prophylaxes. Underlying shifts in microbiome composition due to meteorological factors should be considered in further analyses. Given the expected rise of global temperatures until the end of the century, the topic gains relevance from multiple perspectives.Funding: NoneDisclosures: None

Evaluating infection prevention and control programs in Austrian acute care hospitals using the WHO Infection Prevention and Control Assessment Framework

BackgroundInfection prevention and control (IPC) is crucial for patient safety. The World Health Organization (WHO) has released various tools to promote IPC. In 2018, the WHO released the Infection Prevention and Control Assessment Framework (IPCAF) that enables acute care healthcare facilities to evaluate IPC structures and practices. Data regarding IPC implementation in Austria are scarce. To deliver insights into this topic and promote the IPCAF within the Austrian IPC community, we decided to invite all Austrian hospitals participating in the German nosocomial infection surveillance system to conduct a self-assessment using the WHO IPCAF.MethodsThe IPCAF follows the eight WHO core components of IPC. A German translation of the IPCAF was sent to 127 Austrian acute care hospitals. The survey period was from October to December 2018. Participation in the survey, data entry and transfer to the German national reference center for surveillance of healthcare-associated infections was on a voluntary basis.ResultsAltogether, 65 Austrian hospitals provided a complete dataset. The overall median IPCAF score of all hospitals was 620 (of a possible maximum score of 800), which corresponded to an advanced level of IPC. Of the 65 hospitals, 38 achieved an advanced IPC level. Deeper analysis of the different core components yielded diverse results. Scores were lowest for core components on multimodal strategies for implementation of IPC interventions, and IPC education and training. Around 26% (n = 17) of hospitals reported that the local IPC team was not steadily supported by an IPC committee. Senior clinical staff was not present in the IPC committee in 23% (n = 15) of hospitals. Only 26% (n = 17) of hospitals reported employing at least one IPC professional per ≤250 beds. Surveillance for multidrug-resistant pathogens was not conducted in 26% (n = 17) of hospitals.ConclusionsImplementation of IPC key aspects is generally at a high level in Austria. However, potentials for improvement were demonstrated, most prominently with regard to staffing, IPC education and training, effective implementation of multimodal strategies, and involvement of professional groups. Our survey demonstrated that the IPCAF is a useful tool for IPC self-assessment and can uncover deficits even in a high-income setting like Austria.

The Association of Climatic Factors with Rates of Surgical Site Infections: 17 Years' Data From Hospital Infection Surveillance.

Surgical site infections (SSI) are among the most common healthcare- associated infections. The aim of our explorative study was to determine how selected climatic factors are associated with SSI rates. SSI rates were calculated for operative procedures included in the surgi- cal site infection surveillance component (OP-KISS) of the German Nosocomial Infection Surveillance System (Krankenhaus-Infektions-Surveillance-System, KISS) during the years from 2000 to 2016. The surgeries were associated with department-related and patient-related data. Data of the German Meteorological Service (Deutscher Wetterdienst, DWD), including outdoor temperature and rainfall, were used to analyze the association between climatic factors and rates of SSI. Analyses focused on temperature which showed strong correlations with other climatic parameters. A descriptive analysis was performed, using the chi-squared test. Adjusted odds ratios (AORs) were calculated for SSI rates in relation to tem- perature, using a multivariable logistic regression model. For the altogether 2 004 793 included operative procedures, 32 118 SSIs were documented. Temperatures ≥ 20 °C were associated with a significantly higher occurrence of SSI compared to temperatures <5 °C (AOR: 1.13; 95% confi- dence intervals [1.06; 1.20]). This increase was found for gram-positive pathogens (AOR: 1.13 [1.03; 1.23]) and, even more pronounced, for gram-negative pathogens (AOR: 1.20 [1.07; 1.35]). The association was strongest for superficial SSI caused by gram-negative pathogens (AOR: 1.38 [1.16; 1.64]). An association between climatic factors and SSI rates was demon- strated. The predicted rise in global temperatures by up to 4 °C by the end of this century compared to preindustrial levels may increase the likelihood of SSI and should be taken into consideration in future preventive strategies.

ICU ward design and nosocomial infection rates: a cross-sectional study in Germany

There is increasing interest in the effects of hospital and ward design on multi-faceted infection control. Definitive evidence is rare and the state of knowledge about current ward design is lacking. To collect data on the current status of ward design for intensive care units (ICUs) and to analyse associations between particular design factors and nosocomial infection rates. In 2015, operational infrastructure data were collected via an online questionnaire from ICUs participating voluntarily in the German nosocomial infection surveillance system (KISS). A multi-variate analysis was subsequently undertaken with nosocomial infection rates from the KISS database from 2014 to 2015. In total, 534 ICUs submitted data about their operational infrastructure. Of these, 27.1% of beds were hosted in single-bed rooms with a median size of 18m2 (interquartile range 15-21m2), and 73.5% of all ICU beds had a hand rub dispenser nearby. The authors were able to match 266 ICUs in the multi-variate analysis. ICUs with openable windows in patient rooms were associated with lower device-associated lower respiratory tract infections [odds ratio (OR) 0.73, 95% confidence interval (CI) 0.58-0.90]. ICUs with >40% two-bed rooms were associated with lower primary bloodstream infection rates (OR 0.66, 95% CI 0.51-0.86). Only minor associations were found between design factors and ICU infection rates. Most were surrogates for other risk factors.

Prevalence of carbapenem-resistant organisms and other Gram-negative MDRO in German ICUs: first results from the national nosocomial infection surveillance system (KISS).

Standardized prevalence and incidence data on carbapenem-resistant organisms (CRO) and, as a relevant subgroup, carbapenem-resistant Enterobacteriaceae (CRE) are scarce. CRO-surveillance within the German nosocomial infection surveillance system (KISS) aims to provide epidemiological surveillance data on CRO colonizations and infections. CRO-surveillance is part of a KISS-module for the surveillance of multidrug-resistant organisms (MDRO). MDRO-KISS methods require surveillance of all patients admitted to the ward and standardized documentation of imported and ICU-acquired cases. Data on all MDRO-carriers including colonization and infection with MDRO are collected. All presented data were routine data collected from January 1st 2013 until December 1st 2013 in accordance with the German Protection against Infection Act (IfSG). 341 ICUs submitted data on MDRO during the first year. In total, 5,171 cases of multidrug-resistant Gram-negative bacteria (MRGN) were identified. 848 were CRO (16%). 325 CRO-cases were acquired within the ICU (38%), and 373 CRO-patients had an infection (44%). CRO-prevalence was 0.29 per 100 patients. Acquisition rate of MRGN was 1.32 per 1,000 patient days. This rate is more than doubled the acquisition rates of other MDRO under surveillance within MDRO-KISS (0.57 MRSA, 0.49 VRE). CRO-acquisition rate was 0.3 per 1,000 patient days. Incidence density of MRGN infections bacteria was 0.58 per 1,000 patient days (CRO 0.15/1,000 patient days). To date, CRO are common in German ICUs and the relatively large proportions of ICU-acquired CRO and infections emphasize their potential to cause outbreaks. High MRGN infection rates and high ESBL prevalence data from clinical studies suggest a lack of MRGN identification in asymptomatic carriers.

Ventilator-associated pneumonia in neonates, infants and children

Ventilator-associated pneumonia (VAP) is relatively common in mechanically-ventilated children, but there is a wide variation in reported VAP rates, depending on settings and geographical regions. Surveillance definitions in children are challenging. Although these are provided by the German nosocomial infection surveillance system and an independent Dutch group, the combination of clinical and radiologic signs leaves room for interpretation. Of note, the United States Centers for Disease Prevention and Control guidelines do not offer algorithms for neonates. Despite the fact that most experts agree on the low sensitivity and specificity of existing definitions, little has changed over the past years. However, the number of studies reporting on VAP prevention programs has increased in recent years. Single interventions, such as chlorhexidine mouth wash or stress ulcer prophylaxis, were not effective. Successful prevention programs combined multiple interventions, such as hand hygiene, glove and gown use for endotracheal tube manipulation, backrest elevation, oral care with chlorhexidine, stress ulcer prophylaxis, cuff pressure maintenance where appropriate, use of orogastric tubes, avoidance of gastric overdistension, and elimination of non-essential tracheal suction. These multimodal strategies have proved to be successful among neonates, infants, and children. Importantly, they are applicable in high- as well as in low- and middle-income countries. This review provides an update of VAP incidence rates and summarizes current knowledge on its epidemiology, risk factors, surveillance definitions, and prevention programs in the pediatric setting.

Antibiotic stewardship in Germany: a cross-sectional questionnaire survey of 355 intensive care units

Little information is available on antibiotic prescription management in German hospitals. The objective of this cross-sectional study was to determine the prevalence and components of antibiotic stewardship measures in German intensive care units (ICUs). A questionnaire survey was sent to all ICUs participating in the German nosocomial infection surveillance system (n = 579) in October 2011. Data on antibiotic management structures were collected and analyzed by structural hospital and ICU factors. The questionnaire was completed by 355 German ICUs (response rate 61 %). Common measures used (>80 % of the ICUs) were personnel restrictions for antibiotic prescriptions, routine access to bacterial resistance data, and pharmacy reports on antibiotic costs and consumption. A small proportion of ICUs (14 %) employed physicians specialized in the prescription of antimicrobial medication. Hospitals with their own microbiological laboratory report participation in surveillance networks for antimicrobial use (34 %) and bacterial resistance (32 %) twice as often as hospitals with external laboratories (15 and 14 %, respectively, p < 0.001). Also, non-profit and public hospitals participate more often in surveillance networks for bacterial resistance than private hospitals (>23 % vs. 11 %, p < 0.05). While the majority of ICUs report to have some antibiotic policies established, the contents and composition of these policies vary. Organizational-level control strategies to improve antibiotic management are common in Germany. However, strategies widely considered effective, such as the systematic cross-institutional surveillance of antimicrobial use and bacterial resistance in a standardized manner or the employment of infectious disease specialists, are scarce. This study provides a benchmark for future antibiotic stewardship programs.

Costs and prolonged length of stay of central venous catheter-associated bloodstream infections (CVC BSI): a matched prospective cohort study

Central venous catheter-associated bloodstream infections (CVC BSI) are a common and serious complication among critically ill patients on intensive care units (ICUs), but also result in a financial burden for the health care system. Our aim was to determine the additional costs and length of stay (LOS) of patients with ICU-acquired CVC BSI. We used the surveillance method of the German nosocomial infection surveillance system (Krankenhaus Infections Surveillance System, KISS) to find cases of CVC BSI. The associated costs of CVC BSI were estimated as true costs generated within our hospital. We used a matched cohort design, comparing patients with CVC BSI and patients without BSI. The study period was from January to December 2010. Patients were matched by age, sex, and Simplified Acute Physiology Score (SAPS). The LOS in the ICU of control patients needed to be at least as long as that of CVC BSI patients before the onset of CVC BSI. We matched 40 CVC BSI patients to 40 patients without BSI. The median hospital costs for CVC BSI patients were significantly higher than for patients without BSI (60,445 € vs. 35,730 €; p = 0.006) and the CVC BSI patients stayed longer in the hospital than patients without CVC BSI (44 days vs. 30 days; p = 0.110). The median attributable costs per CVC BSI was 29,909 € (p = 0.006) and the median attributable LOS was 7 days (p = 0.006). CVC BSI is associated with increased hospital costs and prolonged hospital stay. Hospital management should implement control measurements to keep the incidence of CVC BSI as low as possible.

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

BackgroundVery 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.MethodsThe 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.ResultsWe 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).ConclusionsOur 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.

Associations between nosocomial meticillin-resistant Staphylococcus aureus and nosocomial Clostridium difficile-associated diarrhoea in 89 German hospitals

Clostridium difficile is mainly considered as a hospital-acquired pathogen causing diarrhoea in healthcare settings. To quantify and compare the incidence density of hospital-acquired meticillin-resistant Staphylococcus aureus (MRSA) and C.difficile-associated infection (CDI) in a network of German hospitals; also to assess whether there is an association between nosocomial MRSA and nosocomial CDI. Acute hospitals reported data on the number of patients, patient-days and MRSA and/or CDI cases to the German nosocomial infection surveillance system (KISS). Cases were classified as nosocomial or imported. Nosocomial incidences and incidence densities (per 1000 patient-days) of MRSA and CDI were calculated by Spearman correlation index. In 2010, a total of 89 hospitals reported hospital-wide MRSA and CDI cases. The analysis included 1,536,031 patients, 11,138,496 patient-days, 5183 nosocomial CDI cases and 2233 nosocomial MRSA cases. The pooled incidence density of nosocomial CDI was 0.47, more than two-fold higher than that of nosocomial MRSA (0.20). Correlation of nosocomial incidences of MRSA and CDI was statistically significant [correlation coefficient (CC) of 0.515]. Correlation of incidence densities was likewise significant with a CC of 0.484. The incidence of nosocomial CDI was twice as high as nosocomial MRSA incidence among our database and with the definitions used. High nosocomial MRSA or CDI cases might be indicators for deficits in infection control and/or selection pressure of antibiotics.

Secular trends in ESBL, MRSA and VRE incidence in German intensive care units

Aim of our study was to quantify and compare trends in incidence of ESBL producing bacteria, MRSA and VRE in intensive care units participating in the German Nosocomial Infection Surveillance System (ICU-KISS) over the last five years.

Comment on “Pneumonia associated with invasive and noninvasive ventilation: an analysis of the German nosocomial infection surveillance system database”

Comment on “Pneumonia associated with invasive and noninvasive ventilation: an analysis of the German nosocomial infection surveillance system database”

P24.18 Risk factors associated with resistance to 3rd gen cephalosporins in Enterobacteriaceae isolates from intensive care unit patients in Saudi Arabia

P24.18 Risk factors associated with resistance to 3rd gen cephalosporins in Enterobacteriaceae isolates from intensive care unit patients in Saudi Arabia

Pneumonia associated with invasive and noninvasive ventilation: an analysis of the German nosocomial infection surveillance system database

Pneumonia associated with invasive mechanical ventilation (IMV) is one of the indicator infections of the German Nosocomial Infection Surveillance System. In 2005 surveillance was extended to include pneumonia associated with noninvasive ventilation (NIV). The aim of this study was to determine the utilization of IMV and NIV and the associated incidence densities (IDs) of pneumonia and to compare the characteristics of pneumonia cases and the spectrum of associated pathogens. We analyzed the pooled data of 400 intensive care units (ICUs) with respect to three categories of pneumonia: pneumonia associated with IMV and NIV and pneumonia not associated with ventilation. Pooled ventilation utilization rates and pneumonia IDs were calculated in total and stratified by hospital size, hospital type and ICU type. Four hundred ICUs with 779,500 admitted patients, 1,068,472 IMV days and 101,569 NIV days reported 6,869 cases of pneumonia between 2005 and 2007. Of these, 5,811 cases were associated with IMV, 160 with NIV and 898 were not associated with ventilation. The mean pneumonia IDs were 1.58 and 5.44 cases per 1,000 ventilator days for NIV and IMV, respectively. Pneumonia cases associated with IMV were younger, had a longer ICU stay before onset of pneumonia and were more often associated with gram-negative bacteria than cases associated with NIV; however, there were no differences in the proportion of secondary sepsis and death. This surveillance study including pneumonia associated with IMV and NIV and pneumonia not associated with ventilation shows significant differences of pneumonia IDs, patient characteristics and the spectrum of associated pathogens.

Is there an association between nosocomial infection rates and bacterial cross transmissions?*

Surveillance data of nosocomial infection rates are increasingly used for public reporting and interhospital comparisons. Approximately 15% of nosocomial infections on intensive care units are the result of patient-to-patient transmissions of the causative organisms. These exogenous infections could be prevented by adherence to basic infection control measures. The association between bacterial cross transmissions and nosocomial infection rates was analyzed. Prospective cohort study during 24 months. Eleven intensive care units from two university hospitals. All inpatients. None. Primary isolates of six indicator organisms (Acinetobacter baumannii, Enterococcus faecalis and E. faecium, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus) cultured from clinical samples or methicillin-resistant S. aureus surveillance testing of all inpatients were genotyped. Indistinguishable isolates in > or =2 patients defined potential episodes of transmissions. Surveillance of nosocomial infection rates was performed according to the German nosocomial infection surveillance system, Krankenhaus Infektions Surveillance System. Transmission events and nosocomial infection rates were pooled by intensive care unit to calculate Spearman's rank-correlation test. During 100,781 patient days, 100,829 microbiological specimens from 24,362 patients were sampled (average investigation density: 1.0 sample per patient and day) and 3419 primary indicator organisms were cultured. Altogether, 462 transmissions (incidence density of 4.6 transmissions per 1000 patient days; range, 1.4-8.4 days) and 1216 nosocomial infections (incidence density of 12.1 per 1000 patient days; range, 6.2-16.6 days) were discerned. Correlation analysis was unable to reveal any association between the incidence of cross transmissions and nosocomial infections, duration of hospitalization, or device use. Differences in nosocomial infection rates between study intensive care units are not explained solely by cross transmissions. Other factors, like the severity of the patient's underlying diseases, the patient's endogenous flora, or invasive procedures, likely have a dominant effect on the magnitude of nosocomial infection rates.

Regional trends in multidrug-resistant infections in German intensive care units: a real-time model for epidemiological monitoring and analysis

A new surveillance module for multidrug-resistant (MDR) bacteria was added to the intensive care component of the German Nosocomial Infection Surveillance System. Participating intensive care units (ICUs) report data on all patients colonised or infected with meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae (ESBL-EC/KP). To determine the regional distribution of MRSA, VRE and ESBL-EC/KP in Germany, incidence densities (IDs) of these bacteria per 1000 patient-days were calculated for each ICU and pooled for ICUs of five German regions for the years 2005 and 2006. A total of 176 ICUs including 284 142 patients and 1 021 579 patient-days reported data concerning 5490 cases of MDR bacteria. The pooled IDs were 4.54, 0.54 and 0.29 cases per 1000 patient-days for MRSA, ESBL-EC/KP and VRE cases and 1.56, 0.32 and 0.13 per 1000 patient-days for MRSA, ESBL-EC/KP and VRE infections, respectively. While there were no significant differences in the incidence densities of MRSA infections between regions, the IDs of VRE and ESBL-EC/KP infections showed significant regional variation. The regions also differed in the proportion of ICUs per region that reported at least one infection with MRSA, ESBL-EC/KP or VRE in 2005-2006 and these differences ranged from 82% to 91% for MRSA, from 34% to 76% for ESBL-EC/KP and from 8% to 42% for VRE. This new surveillance module enables ICUs to monitor the occurrence of MDR bacteria by comparing local incidence densities with a national reference and shows significant regional variation of MDR bacteria in Germany.

New identification of outliers and ventilator-associated pneumonia rates from 2005 to 2007 within the German Nosocomial Infection Surveillance System

This study presents data for ventilator use and ventilator-associated pneumonia (VAP) rates from the German hospital surveillance system for nosocomial infections (KISS: Krankenhaus Infektions Surveillance System). New Centers for Disease Control and Prevention (CDC) definitions became effective during 2005 and we describe the new method used by KISS to determine individual units with data at extreme ranges. The number of VAP cases per 1000 device-days was calculated and a new visual method, specifically funnel plots, was introduced to identify outliers. The VAP rate will be highly influenced by chance variability if only a few VAP cases are observed during a low number of ventilator-days. Funnel plots take this relationship between event rate and volume of cases into account. A total of 391 intensive care units (ICUs) reported surveillance data from 8 86 816 patients and included 6896 VAPs and 3 113 983 patient-days for the period January 2005 to December 2007. The mean VAP rate according to the new CDC definitions was 5.5 cases per 1000 ventilator-days (median: 4.4). The mean ventilator use in all ICUs was 35.7 (median: 29.3). Funnel plots identified 14.3% as outliers; 34 of them as high, and 22 as low, outliers. Since 2008, visual feedback to the KISS ICUs has been supplied by funnel plots. These are less prone to misinterpretation than histograms and they indicate when investigation is required for increasing VAP.