Reduction of Surgical Site Infection Rates Associated With Active Surveillance

Objective.

To evaluate whether surgical site infection (SSI) rates decrease in surgical departments as a result of performing active SSI surveillance.

Design.

Retrospective multiple logistic regression analyses.

Setting.

A group of 130 surgical departments of German hospitals participating in the Krankenhaus Infektions Surveillance System (KISS).

Methods.

Data for 19 categories of operative procedures performed between January 1997 and June 2004 were included (119,114 operations). Active SSI surveillance was performed according to National Nosocomial Infections Surveillance system (NNIS) methods and definitions. Departments' SSI rates were calculated individually for each year of surveillance and for each operative procedure category, taking into account when the individual departments had begun their surveillance activities. Multiple logistic regression analyses on a single operation basis were carried out with stepwise variable selection to predict outcomes for patients with SSI. The variables included were as follows: the department's year of participation, NNIS risk index variables, patients' age and sex, and the hospitals' structural characteristics, such as yearly operation frequency, number of beds, and academic status.

Results.

For 14 of 19 operative procedure categories analyzed, there was a tendency toward lower SSI rates that was associated with increasing duration of SSI surveillance. In multiple logistic regression analyses of pooled data for all operative procedures, the departments' participation in the surveillance system was a significant independent protective factor. Compared with the surveillance year 1, the SSI risk decreased in year 2 (odds ratio, 0.84; 95% confidence interval, 0.77-0.93) and in year 3 (odds ratio, 0.75; 95% confidence interval, 0.68-0.82), and there was no change in year 4.

Conclusion.

The SSI incidence was reduced by one quarter as a result of the surveillance-induced infection control efforts, which indicates the usefulness of a voluntary surveillance system.

Trends in Ventilator-Associated Pneumonia Rates Within the German Nosocomial Infection Surveillance System (KISS)

Objective.

To investigate trends in ventilator-associated pneumonia (VAP) rates during participation in the German nosocomial infection surveillance system (Krankenhaus-Infektions-Surveillance-System [KISS]).

Methods.

A total of 71 ICUs that began participating in KISS in 1999 or later and continued participation for at least 36 months were selected. Beginning with the first month of participation, the pooled mean rate of VAP in the ICUs was calculated for each year of participation. The incidence densities for the 3 years of participation were compared using the Pearson x2 test. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated. VAP rates were calculated for each ICU and year of participation, and rates for years 1 and 3 were compared using the Wilcoxon test for paired samples.

Results.

Twenty-nine medical-surgical, 18 medical, 20 surgical, 2 neurosurgical, and 2 pediatric ICUs met the selection criteria. Surveillance data were available on 181,275 patients, for whom there were 613,098 patient-days and 224,138 ventilator-days. A total of 2,043 cases of VAP were reported. The ICUs had a pooled VAP rate of 10.5 cases per 1,000 ventilator-days during year 1 of KISS surveillance. In year 2, the rate decreased by 19%, to 8.7 cases per 1,000 ventilator-days (RR, 0.81 [95% CI, 0.73-0.90]). In year 3, the rate decreased by 24% from year 1, to 8.0 cases per 1,000 ventilator-days (RR, 0.76; 95% CI, 0.68-0.85). Both results were significant (P < .001 by the Pearson x2 test). Comparison of the VAP rates of the ICUs did not show a significant difference between years 1 and 3 of KISS participation.

Conclusion.

Surveillance was associated with a significant reduction in the pooled rate of VAP during years 1-3 of KISS participation.

[Tuberculosis infection control - recommendations of the DZK]

The epidemiological situation of tuberculosis (TB) in Germany has improved considerably during the past few years. However, those in unprotected contact with infectious tuberculosis patients frequently and/or over longer periods of time and/or intensively continue to have a higher risk for TB infection. Rapid diagnosis, prompt initiation of effective treatment, and adequate infection control measures are of particular importance to prevent infection. The present recommendations depict the essentials of infection control as well as specific measures in the hospital (isolation, criteria for its duration and technical requirements, types of respiratory protection, disinfection measures, waste disposal). The specific requirements for outpatients (medical practice), at home, for ambulance services, and in congregate settings, including prisons, are also addressed. Compared with the previous recommendations the pattern of respiratory protection measures has been simplified. As a rule, hospital staff and those visiting infectious tuberculosis patients are advised to wear respiratory protection that satisfies the criteria of FFP2-masks (DIN EN 149), while patients should wear mouth-nose protectors (surgical masks) in the presence of others and outside the isolation room. A detailed depiction of criteria for isolation and its duration in smear positive and only culturally confirmed pulmonary tuberculosis has been added.

[Tuberculosis infection control--recommendations of the DZK]

The epidemiological situation of tuberculosis (TB) in Germany has improved considerably during the past few years. However, those in unprotected contact with infectious tuberculosis patients frequently and/or over longer periods of time and/or intensively continue to have a higher risk for TB infection. Rapid diagnosis, prompt initiation of effective treatment, and adequate infection control measures are of particular importance to prevent infection. The present recommendations depict the essentials of infection control as well as specific measures in the hospital (isolation, criteria for its duration and technical requirements, types of respiratory protection, disinfection measures, waste disposal). The specific requirements for outpatients (medical practice), at home, for ambulance services, and in congregate settings, including prisons, are also addressed. Compared with the previous recommendations the pattern of respiratory protection measures has been simplified. As a rule, hospital staff and those visiting infectious tuberculosis patients are advised to wear respiratory protection that satisfies the criteria of FFP2-masks (DIN EN 149), while patients should wear mouth-nose protectors (surgical masks) in the presence of others and outside the isolation room. A detailed depiction of criteria for isolation and its duration in smear positive and only culturally confirmed pulmonary tuberculosis has been added.

Outbreak of carbapenem-resistant Pseudomonas aeruginosa infection in a surgical intensive care unit

Infection control personnel performing surveillance activities noticed a cluster of patients with isolates of carbapenem-resistant Pseudomonas aeruginosa (CRPA) in the surgical intensive care unit (SICU) of a German University Hospital. An outbreak investigation including a descriptive analysis, a case-control study comparing 15 CRPA case patients with 18 patients with carbapenem-susceptible P. aeruginosa, environmental sampling and pulsed-field gel electrophoresis (PFGE) typing of P. aeruginosa isolates was carried out. Fifteen patients acquired CRPA in the SICU during the outbreak period between 1 July 2006 and 31 October 2006 and PFGE typing of 11 available patient isolates revealed two outbreak strains as well as sporadic CRPA isolates. Both outbreak strains were resistant to penicillins, cephalosporins, carbapenems, aminoglycosides and quinolones, and remained susceptible only to colistin. The most likely mode of transmission was cross-transmission between patients during postoperative wound care with abdominal and/or thoracic drains (odds ratio: 64.33; 95% confidence interval: 5.32-999) and therapy with quinolones (48.37; 3.71-999) being independent risk factors for acquisition of CRPA. No further clusters of CRPA cases were observed after implementation of contact isolation precautions and after healthcare workers were made aware of the likely mode of transmission. This study shows the complex epidemiology of CRPA in a SICU including cross-transmission of two CRPA strains related to postoperative wound care.

[Costs due to urinary tract infections in Germany. An estimation based on the data from the German National Nosocomial Infections Surveillance System]

BACKGROUND

We estimated the avoidable costs due to nosocomial urinary tract infections (UTI) based on the data of the German National Nosocomial Infections Surveillance System (KISS).

METHODS

The incidence of nosocomial UTI derived from KISS reference data. The overall number of patient days was obtained from the "Statistische Bundesamt" (German Federal Office of Statistics). Expected costs for a single UTI were estimated according to data published in the medical literature.

RESULTS

On average, there were 1.87 UTI on intensive care units (ICU) and 0.81 UTI on peripheral wards per 1,000 patient days; 4.5% of the annual 146.1 million patient days in German hospitals were contributed by ICUs. In total, there are approximately 155,000 nosocomial UTI every year. Each UTI leads to costs of about 1,000 euros; 20% of all nosocomial infections are preventable.

CONCLUSIONS

Just for nosocomial UTI, appropriate infection control measures may reduce the annual health care costs by 14,500 euros for every German hospital.

[Surgical site infection rates using a laparoscopic approach: results of the German national nosocomial infections surveillance system]

BACKGROUND

Our aim was to assess the impact of laparoscopy on surgical site infections.

METHODS

An analysis was performed using the data of the German national nosocomial infections surveillance system (Krankenhaus-Infektions-Surveillance-Systems, KISS) collected during the period from January 2001 to June 2006. Univariate and multivariate analyses were used to investigate the influence of age, gender, ASA score, duration of surgery, wound contamination class and surgical technique.

RESULTS AND CONCLUSIONS

A total of 18,249 appendectomies, 32,912 herniorrhaphies, 42,949 cholecystectomies and 19,523 colon operations were analysed. The overall surgical site infection rate was significantly higher (2.6-fold) for the open approach compared to laparoscopically performed appendectomies. For herniorrhaphies, cholecystectomies and colon operations the corresponding odds ratios were 3.40, 3.22 and 1.20 respectively. Whenever possible a laparoscopic approach should be used.

Intensified strategies to control vancomycin-resistant enterococci in immunocompromised patients

Increasing colonization and infection with vancomycin-resistant enterococci (VRE) in immunocompromised patients are associated with increased mortality. Despite contact precautions for VRE control, rapid limitation of its spread is often impossible. We report on a VRE outbreak in a hematologic/oncologic unit including 33 patients. Although 28 of the patients had only VRE colonization, VRE-related infection was probable in 4 patients, and VRE infection of the bloodstream occurred in 1 case. Two patients were identified by VRE screening on admission, 20 were identified by weekly routine VRE screening, and 6 were identified from specimens taken to clarify infections (eg, urine, bronchoalveolar lavage). Five individuals acquired VRE colonization as inpatients (contact patients). Multiple-locus variable-number tandem repeat analysis (MLVA) proved that the outbreak was caused by VanA gene-positive Enterococcus faecium belonging to MLVA genogroup C1(MLVA types 1, 7, 12). The outbreak strains exhibited the potential virulence factor esp(enterococcus surface protein). The outbreak was terminated within 2 months by intensified infection-control measures, including quarantine and the cohorting of patients who tested positive for VRE; however, VRE spread recurred after the measures were discontinued but was again limited by resuming the measures. We conclude that intensive infection-control strategies enable the timely termination of VRE outbreaks, even those involving VRE strains with high epidemic potential on "high-risk wards" (eg, hematologic/oncologic units). Premature discontinuation of infection-control measures may cause recurrence of the VRE spread.

Different trends of MRSA and VRE in a German hospital, 1999-2005

Some of the clinically most menacing nosocomial pathogens are Methicillin-resistent Staphylococcus aureus (MRSA) and Vancomycin-resistent Enterococcus (VRE). During the last years both pathogens showed dramatic increases in colonization and infection rates in Germany. This study covers all patients positively tested for MRSA and VRE in a German University Hospital from 1999-2005. About 1,179 MRSA cases and 116 VRE cases have been reported. VRE was significantly associated with less infection, female gender, more death and higher nosocomial acquisition than MRSA. While MRSA rates increased impressively from 1999 to 2005 VRE rates decreased clearly. Assuming that compliance with hygienic measures is similar in dealing with MRSA and VRE it is quite unclear why these two major pathogens differ so much in their trends. One possibility is that the MRSA problem has been caused by an increasing share of nonnosocomially acquired MRSA.

Reducing neonatal nosocomial bloodstream infections through participation in a national surveillance system

A national nosocomial surveillance system for neonatal intensive care patients with a very low birthweight was set up in Germany in 2000 (NEO-KISS). Forty-eight neonatal intensive care units (NICUs) participated in the programme, which focused upon nosocomial bloodstream infections (BSIs) and pneumonia. Only data from NICUs participating for at least three years were included and the years compared. The relative risks and their 95% confidence intervals (CIs) were calculated and a multiple logistic regression analysis performed to identify significant risk factors. Twenty-four units that met the selection criteria accumulated data for 3856 patients and 152 437 patient-days in their first three years of participation. The incidence density of BSIs decreased significantly by 24% from 8.3 BSIs per 1000 patient-days in the first year to 6.4 in the third year. In the multiple logistic regression analysis, BSI in the third year of participation was significantly lower than in the first year of participation (odds ratio=0.73, 95% CI 0.60-0.89). The year of participation was an independent risk factor for BSI but not for pneumonia. Our data suggest that participation in ongoing surveillance of nosocomial infections in NICUs, requiring individual units to feedback data, may lead to a reduction in BSI rates.

Risk factors for death due to nosocomial infection in intensive care unit patients: findings from the Krankenhaus Infektions Surveillance System

OBJECTIVE

To determine risk factors for death among patients with nosocomial pneumonia and patients with primary bloodstream infections (BSI) in intensive care units (ICUs).

DESIGN

Prospective cohort study.

SETTING

Data collected from January 1997 through June 2003 from ICUs registered with the Krankenhaus Infektions Surveillance System in Germany.

PATIENTS

A total of 8,432 patients with nosocomial pneumonia from 202 ICUs and 2,759 patients with nosocomial primary BSI from 190 ICUs.

METHODS

The following risk factors were considered in the analysis: age, sex, time in the ICU before onset of infection, type of ICU, type and size of hospital, intubation, central venous catheter use, total parenteral nutrition, and type of pathogen.

RESULTS

A total of 750 patients (8.9%) with nosocomial pneumonia and 302 patients (10.9%) with nosocomial primary BSI died. Multiple logistic regression analysis identified treatment in a medical or surgical ICU (odds ratio [OR], 1.55 [95% confidence interval {CI}, 1.32-1.82]) or a hospital with more than 1,000 beds (OR, 2.14 [95% CI, 1.81-2.56]), age older than 65 years (OR, 1.54 [95% CI, 1.31-1.81]), and infection with methicillin-resistant Staphylococcus aureus (OR, 2.39 [95% CI, 1.81-3.12]) or multidrug-resistant Pseudomonas aeruginosa (OR, 3.00 [95% CI, 1.90-4.63]) as independent determinants of death from nosocomial pneumonia. Age older than the median of 63 years (OR, 1.44 [95% CI, 1.12-1.86]) and methicillin-resistant S. aureus as the causative agent (OR, 2.98 [95% CI, 1.81-5.82]) were both associated with increased mortality from primary BSI. The types of infecting pathogens, particularly those resistant to multiple drugs, were also strong outcome predictors among ICU patients.

CONCLUSIONS

The study results underline the need for further investigations of the role of antimicrobial resistance in the outcome of patients with nosocomial pneumonia and patients with primary BSI.

Closure of medical departments during nosocomial outbreaks: data from a systematic analysis of the literature

A total closure of an affected medical department is one of the most expensive infection control measures during investigation of a nosocomial outbreak. However, until now there has been no systematic analysis of typical characteristics of outbreaks, for which closure was considered necessary. This article presents data on features of such nosocomial epidemics published during the past 40 years in the medical literature. A search of the Outbreak Database (1561 nosocomial outbreaks in file) revealed a total of 194 outbreaks that ended up with some kind of closure of the unit (median closure time: 14 days). Closure rates (CRs) were calculated and stratified for medical departments, for causative pathogens, for outbreak sources, and for the assumed mode of transmission. Data were then compared to the overall average CR of 12.4% in the entire database. Wards in geriatric patient care were closed significantly more frequently (CR: 30.3%; P < 0.001) whereas paediatric wards showed a significantly lower CR (6.1%; P = 0.03). Pathogen species with the highest CR were norovirus (44.1%; P < 0.001) and influenza/parainfluenza virus (38.5%; P < 0.001). If patients were the source of the outbreak, the CR was significantly increased (16.7%; P = 0.03). Infections of the central nervous system were most often associated with closure of the ward (24.2%; P = 001). A systematic evaluation of nosocomial outbreaks can be a valuable tool for education of staff in the absence of an outbreak, but may be even more helpful for potentially cost-intensive decisions in the acute outbreak setting on the ward.

Risk factor analysis of blood stream infection and pneumonia in neutropenic patients after peripheral blood stem-cell transplantation

The purpose of this study was to analyse risk factors for blood stream infection (BSI) and pneumonia in neutropenic patients who have undergone peripheral blood stem-cell transplantation (PBSCT). Data were taken from the ONKO-KISS multicenter surveillance project. Infections were identified using CDC definitions (laboratory-confirmed BSI) and modified criteria for pneumonia in neutropenic patients. The multivariate analysis was performed using the Fine-Gray regression model for the cumulative incidences of the competing events 'infection', 'death' and 'end of neutropenia'. The risk factors investigated were: sex, age, underlying disease and type of transplant. From January 2000 to June 2004, a total of 1699 patients in 20 hospitals were investigated. In the multivariate analysis, male patients had a significantly higher risk of acquiring BSI than female patients (P=0.002). The risk of acquiring BSI is highest in patients with advanced acute myeloid leukaemia (AML). In the univariate and multivariate analysis, unrelated donor allogeneic transplantation constituted a risk factor for pneumonia (P=0.012). ONKO-KISS provides reference data on the incidence of pneumonia and BSI. The increased risk for BSI in males and patients with advanced AML, and the increased risk for pneumonia in unrelated donor allogeneic PBSCT patients should be targeted to prevent infections in these higher risk groups.

Is the prevalence of Stenotrophomonas maltophilia isolation and nosocomial infection increasing in intensive care units?

The study presented here was conducted over a period of 4 years (2001-2004) to investigate changes in the number of S. maltophilia isolates detected per 1,000 patient days and to look at the incidence density of nosocomial infections caused by S. maltophilia. The analysis was based on data provided by 34 German intensive care units participating continuously in the national project "Surveillance of Antimicrobial Use and Resistance in ICUs"; 31 of these ICUs reported nosocomial infections to the German infection surveillance system, KISS, during the study period.

Hand rub consumption and hand hygiene compliance are not indicators of pathogen transmission in intensive care units

The objective of this study was to investigate whether nosocomial infection (NI) rates, hand hygiene compliance rates and the amount of alcohol-based hand rub used for hand disinfection are useful indicators of pathogen transmission in intensive care units (ICUs), and whether they could be helpful in identifying infection control problems. All isolates of 10 of the most frequent pathogens from patients who were hospitalized in an ICU for >48 h were genotyped to identify transmission episodes in five ICUs. The incidence of transmission was correlated with hand hygiene compliance, hand rub consumption and NI rates. The incidence of transmission episodes varied between 2.8 and 6.8 in the five ICUs. The NI rate was 8.6-22.5 per 1000 patient-days, hand hygiene compliance was 30-47% and hand rub consumption was 57-102 L per 1000 patient-days. There was no correlation between the incidence of transmission episodes and hand rub consumption or hand hygiene compliance. The correlation between transmission rates and NI rates was 0.4 (P = 0.5), and with the exclusion of one ICU, it was 1 (P < 0.01). The incidence of NI is a relatively good indicator for the identification of pathogen transmissions, but hand rub consumption and hand hygiene compliance, at least with the relatively low level of compliance found in this study, are not indicators of pathogen transmission.

Reduction of surgical site infections after Caesarean delivery using surveillance

Since 1997, the Krankenhaus Infektions Surveillance System (KISS) has collected data on surgical site infections (SSIs) following Caesarean delivery (CD). The aim of this study was to determine whether surveillance and feedback of healthcare-associated infections (HAIs) could reduce the infection rate after CD. Only departments that had participated in KISS for at least three years were included in the analysis. The CD infection rates of the first, second and third years of KISS participation were compared for significant differences. The relative risk was calculated for the first and the third year of KISS participation. Multi-variate logistic regression analysis was performed to detect significant risk factors for SSI after CD using the third year of participation as one parameter. Twenty-six of 52 obstetric and gynaecology departments met the study's inclusion criteria. In those 26 departments, 17,405 CD procedures were performed and 331 SSIs were recorded (1.9%). The SSI rate after CD procedures was significantly reduced in the third year of KISS participation (1.6%) compared with the first year of KISS participation (2.4%), with a relative risk of 0.63 [95% confidence interval (CI) 0.48-0.82]. Logistic regression analysis confirmed that KISS participation over three years was an independent factor for the reduction of SSI rate (odds ratio 0.64; 95% CI 0.49-0.83). As shown previously for other types of HAI, this study demonstrated that continuous surveillance and comparison with stratified reference data could reduce SSI infection rates after CD.

Effectiveness of a nationwide nosocomial infection surveillance system for reducing nosocomial infections

In recent years, several countries have established surveillance systems for nosocomial infections (NIs) on a national basis. Limited information has been published on the effectiveness of these national surveillance systems. The aim of this study was to investigate whether participation in the German national NI surveillance system [Krankenhaus Infektions Surveillance System (KISS)] resulted in reduced rates of NIs. Three major NIs were studied: ventilator-associated pneumonia (VAP) and central-venous-catheter-related primary bloodstream infections (CR-BSIs) in intensive care units (ICUs), and surgical site infections (SSIs) in surgical inpatients. Data were collected from January 1997 until December 2003. Only institutions that had participated in KISS for at least 36 months were considered for analysis. Data from the first 12 months of surveillance were compared with data from the second and third 12-month periods. One hundred and fifty ICUs and 133 surgical departments fulfilled the inclusion criteria. In their first year of participation in KISS, the ICUs had an average VAP rate of 11.2 per 1000 ventilator-days and a CR-BSI rate of 2.1 per 1000 catheter-days. The average SSI rate in the surgical inpatients was 1.6 per 100 operations in their first year of participation. Comparing the infection rates in the third year with the first year, the relative risk (RR) for VAP was 0.71 [95% confidence intervals (CI) 0.66-0.76] and the RR for CR-BSI was 0.80 (95% CI 0.72-0.90). The corresponding RR for SSI was 0.72 [95% CI 0.64-0.80]. Participation in KISS was associated with a significant reduction in these three NIs.

Postoperative Wundinfektionen

Surgical site infections can be traced to discrepancies in one specific hospital department: the operating suite. Therefore, prevention is often viewed as resting completely on the surgeon. However, the source of micro-organisms responsible for surgical site infections can be endogenous or exogenous. Most infections are believed to be the former, i.e. caused by micro-organisms already resident in the patient's body. Therefore the surgeon can be regarded as suspect only in exceptional cases and usually himself a victim. Prevention is possible not only for exogenous surgical site infection but also many endogenous infections. A multicenter surveillance of infection rates at 130 operative departments participating for at least 4 years in the German National Nosocomial Infection Surveillance System was conducted. A significant 25% reduction in the 3rd year was observed compared with patients who underwent surgery within the 1st year of participation. However, surgeons alone cannot achieve such a decrease, and a team approach is required under most circumstances.

Use of multistate models to assess prolongation of intensive care unit stay due to nosocomial infection

BACKGROUND

Reliable data on the costs attributable to nosocomial infection (NI) are crucial to demonstrating the real cost-effectiveness of infection control measures. Several studies investigating this issue with regard to intensive care unit (ICU) patients have probably overestimated, as a result of inappropriate study methods, the part played by NIs in prolonging the length of stay.

METHODS

Data from a prospective study of the incidence of NI in 5 ICUs over a period of 18 months formed the basis of this analysis. For describing the temporal dynamics of the data, a multistate model was used. Thus, ICU patients were counted as case patients as soon as an NI was ascertained on any particular day. All patients were then regarded as control subjects as long as they remained free of NI (time-to-event data analysis technique).

RESULTS

Admitted patients (n=1,876) were observed for the development of NI over a period of 28,498 patient-days. In total, 431 NIs were ascertained during the study period (incidence density, 15.1 NIs per 1,000 patient-days). The influence of NI as a time-dependent covariate in a proportional hazards model was highly significant (P< .0001, Wald test). NI significantly reduced the discharge hazard (hazard ratio, 0.72 [95% confidence interval, 0.63-0.82])--that is, it prolonged the ICU stay. The mean prolongation of ICU length of stay due to NI (+/- standard error) was estimated to be 5.3+/-1.6 days.

CONCLUSIONS

Further studies are required to enable comparison of data on prolongation of ICU length of stay with the results of various study methods.

Correlation between the genetic diversity of nosocomial pathogens and their survival time in intensive care units

Bacteria differ in their ability to survive in the hospital environment outside the human host. Species remaining viable and infectious have a higher chance of being transmitted, giving them a fitness advantage in hospitals. This differential fitness could be expected to alter the genetic population structure of bacterial populations in hospitals, and should be reflected by the relative abundance of several successful clones. The objective of this study was to test for a potential correlation between tenacity, i.e. environmental survival, and clonal abundance determined by the genetic diversity in different bacterial species from prospectively collected isolates of intensive care patients. A literature review was performed to identify mean environmental survival times for the most important pathogens in intensive care units (ICUs): Staphylococcus aureus, enterococci, Acetinobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., Escherichia coli, Klebsiella pneumoniae and Stenotrophomonas maltophilia. To determine the genetic diversity of the natural population of these species in ICUs, a prospective 18-month study was conducted in five units with median nosocomial infection rates. All clinical isolates were collected, and highly discriminatory DNA fingerprinting techniques were used to identify specific clones. A diversity index for each species was calculated as the number of distinguishable genotypes in the population divided by size. The correlation between survival times and the diversity indices for the individual pathogens was investigated using non-parametric methods. Although 21 studies were identified in the literature, only two were relevant. They showed median survival times between 1.5 days (P. aeruginosa) and 60.0 days (Enterococcus faecium). During the prospective ICU study, 1264 pathogens were investigated and simple diversity indices between 49.1 (Enterococcus faecalis) and 89.8 (E. coli) were found. A correlation between survival times and the diversity indices for the individual pathogens was found (correlation coefficient 0.821, P=0.024). Environmental survival may be an important factor contributing to the ecological fitness of some nosocomial pathogens in ICUs. Infection control measures should consider this finding.

Elemental carbon and respirable particulate matter in the indoor air of apartments and nursery schools and ambient air in Berlin (Germany)

This study was performed to examine exposure to typical carcinogenic traffic air pollutants in the city center of an urban area. In all, 123 apartments and 74 nursery schools were analyzed with and without tobacco smoke interference and the households in two measuring periods. Simultaneously, the air outside 61 apartment windows as well as the average daily traffic volume were measured. Elemental carbon (EC), the marker for particulate diesel exhaust and respirable particulate matter (RPM) were determined. The thermographic EC analysis was conducted with and without prior solvent extraction of the soluble carbon fraction. Comparison of these two thermographic EC measurements clearly showed that method-related differences in the results, especially for indoor measurements, when high background loads of organic material were present (e.g. tobacco smoke), existed. Solvent extraction prior to EC determination was therefore appropriate. For the first winter measuring period, the EC concentration levels without solvent extraction in the indoor air were about 50% higher than those measured in the spring/summer period. In the second measuring period (i.e. spring/summer), the median EC concentrations after solvent extraction were 1.9 microg/m3 for smokers' apartments and 2.1 microg/m3 for non-smokers' apartments, with RPM concentrations of 57 and 27 microg/m3, respectively. Nursery schools showed high concentrations with median values of 53 microg/m3 for RPM and 2.9 microg/m3 for EC after solvent extraction. A significant correlation between the fine dust and EC concentrations (after solvent extraction) in the indoor and ambient air was determined. Outdoor EC values were also correlated with the average daily traffic volume. The EC ratios between indoor and ambient concentration showed a median of 0.8 (range: 0.3-4.2) in non-smoker households and 0.9 (range: 0.4-1.5) in smoker apartments. Furthermore, the EC/RPM ratio in indoor and ambient air was 0.01-0.15 (median 0.06) and 0.04-0.37 (median 0.09), respectively.

PRACTICAL IMPLICATIONS

In the absence of indoor sources a significant correlation with regard to respirable particulate matter (RPM) and elemental carbon concentrations between the indoor and ambient air of apartments was observed. The high degree of certainty resulting from this correlation underscores the importance of ambient air concentrations for indoor air quality. In nursery schools we found higher concentrations of RPM. An explanation of these results could be the high number of occupants in the room, their activity and the cleaning intensity.

Hygienemaßnahmen auf Intensivstationen

BACKGROUND

Aim of this study was to determine to what extent evidence-based infection control recommendations are applied in German intensive care units (ICUs).

METHODS

A questionnaire concerning handling of tubes, central vascular catheters (CVC), urinary tract catheters and methicillin-resistant Staphylococcus aureus (MRSA) positive patients was sent to 230 participants of the German Nosocomial Infection Surveillance System (KISS).

RESULTS

Nasal intubation is routinely performed in 9% of ICUs, all recommended measures for CVC insertion were obeyed by 43% of ICUs and one-third of ICUs conduct regular screening of urine in catheterized patients. Urinary tract catheters are replaced at defined time intervals in 37% of ICUs. MRSA positive patients are not isolated in 5% of ICUs. MRSA screening on admission is not performed for high risk patients in 16% of ICUs.

CONCLUSIONS

There are still many German ICUs in which evidence-based recommendations are not implemented. Training of staff is necessary to improve quality of patient care.

Reduction of orthopaedic wound infections in 21 hospitals

INTRODUCTION

The German national nosocomial infections surveillance system (KISS) has been collecting surveillance data from hip and knee prosthesis operations since 1997. The purpose of this article is to investigate whether surveillance and feedback of surgical site infection (SSI) information to the physicians and nurses of participating hospitals lead to reduced SSI rates or not.

MATERIALS AND METHODS

Only information from hospitals previously participating for at least 3 years was used for the analysis. Monthly SSI rates were pooled over the 36-month period, beginning in each clinic's case with its first month of participation, the rates then being compared for 12-month periods. Relative risks were calculated for comparison of the SSI rates in the first and third years of participation. A multiple logistic regression analysis with stepwise variable selection was performed to identify significant risk factors, including the year of surveillance after starting surveillance activities.

RESULTS

The overall SSI rates were 1.4% for hip prosthesis and 1.0% for knee prosthesis. Fourteen clinics participated in KISS for at least 3 years continuously with HIP prostheses and 21 with knee prostheses. It was possible to include a total of 15,457 hip and 9,011 knee procedures for this analysis. A comparison of data from the first and the third years show a significant SSI reduction with hip procedures, with a relative risk of 0.54 (CI95 0.38-0.77), and a trend towards reduced SSI rates for knee procedures. The multiple logistic regression analysis confirmed that the SSI rate for hip prosthesis was significantly lower in the third year than in the first year of surveillance (OR = 0.57; CI95 0.42-0.78), though for knee prosthesis the level of significance was not achieved.

CONCLUSION

A reduction of SSIs following hip and knee prosthesis operations through the introduction of ongoing surveillance and the possibility of using benchmark data for comparison does seem to be possible in many institutions.

Effectiveness of a hospital-wide selective screening programme for methicillin-resistant Staphylococcus aureus (MRSA) carriers at hospital admission to prevent hospital-acquired MRSA infections

Screening of potential MRSA-positive patients at hospital admission is recommended in German and international guidelines. This policy has been shown to be effective in reducing the frequency of nosocomial MRSA transmissions in the event of an outbreak, but the influence of screening on reducing hospital-acquired MRSA infections in a hospital setting where MRSA is endemic is not yet well-documented. This study describes the effect of hospital-wide screening of defined risk groups in a 700-bed acute care hospital during a period of 19 months. In a cohort study with a 19-month control period, the frequencies of hospital-acquired MRSA infections were compared with and without screening. In the control period, there were 119 MRSA-positive patients, of whom 48 had a hospital-acquired MRSA infection. On the basis of this frequency, a predicted total of 73.2 hospital-acquired MRSA infections was calculated for the screening period, but only 52% of the expected number (38 hospital-acquired MRSA infections) were observed, i.e., 48% of the predicted number of hospital-acquired MRSA infections were prevented by the screening programme. The screening programme was performed with minimal effort and can therefore be recommended as an effective measure to help prevent hospital-acquired MRSA infections.

Use of terminal tap water filter systems for prevention of nosocomial legionellosis

Hospital water supplies often contain Legionella spp. and represent a potential source of nosocomial infection, especially for immunocompromised patients or those in intensive care units. Therefore, pathogen-free water should be provided for such high-risk patients. Surveillance of splash water was performed in high-risk patient care areas at Berlin Charité-University Medicine (506 samples) and Medical School Hannover (767 samples) to investigate the ability to provide water that was free from Legionella spp. by the use of disposable, terminal tap water filter systems with non-impregnated, as well as impregnated, filters with prolonged usage intervals. Twenty (Berlin) and 32 (Hannover) water outlets were provided with disposable filters with a pore size of 0.2 microm. Testing of unfiltered tap water revealed growth of Legionella spp. in 53 of 210 (Berlin) and 30 of 32 (Hannover) samples. Non-impregnated, terminal, disposable water filters at taps used for high-risk patient care led to water free from Legionella spp. in 154 of 155 (99.4%) samples after three to four days and in 137 of 141 (97.2%) samples after six to seven days. When testing a new impregnated filter, 255 of 256 (99.6%) samples remained free from Legionella spp. after continuous use for seven days, as recommended by the manufacturers, and also after 10 days. Samples that were positive for Legionella spp. contained 1-4 cfu/mL. We believe that an impregnated filter system is suitable for the prevention of nosocomial Legionellosis in high-risk patient care areas.

Mortality risk factors with nosocomial Staphylococcus aureus infections in intensive care units: results from the German Nosocomial Infection Surveillance System (KISS)

INTRODUCTION

As the number of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infections in German intensive care units increases, the problem of MRSA infection as such is becoming ever more serious. The aim of this study was to investigate whether mortality rates from nosocomial MRSA pneumonia and primary bloodstream infections (BSI) differ significantly from those of nosocomial pneumonia and primary BSI caused by methicillin-susceptible S. aureus (MSSA).

METHODS

For the analysis data from the ICU component of the German nosocomial infection surveillance system (KISS) were used (January 1997 to June 2002). To identify mortality risk factors a logistic regression analysis with step-wise variable selection was conducted including all cases of nosocomial S. aureus pneumonia and primary BSI. The possible risk factors that were evaluated were age > median, male gender, time in the ICU before infection > median, type of ICU, type and size of hospital, intubation, CVC use, total parenteral nutrition, year of investigation, infection caused by MRSA.

RESULTS

Data from 274 ICUs and 505,487 ICU patients were recorded and a total of 6,888 cases of nosocomial pneumonia and 2,357 cases of primary BSI identified, of which 1,851 cases of S. aureus pneumonia and 378 cases of S. aureus primary BSI were considered for analysis. 59 of the 349 patients with MRSA pneumonia (16.9%) and 105 of the 1,502 patients with MSSA pneumonia (7.0%) died. 16 of the 95 patients with primary MRSA BSI (16.8%) and 17 of the 283 patients with primary MSSA BSI died (6.0%). Four factors were significantly associated with mortality from S. aureus pneumonia, one of them being pneumonia caused by MRSA (OR = 2.62; CI95 1.69-4.02). Only MRSA was significantly associated with death from S. aureus primary BSI (OR = 3.84; CI95 1.51-10.2).

CONCLUSION

Nosocomial pneumonia and primary BSI from MRSA may be associated with death, but the cause-effect relationship of severity of illness and MRSA remains to be determined due to the limitations of surveillance data.

Letalität auf deutschen Intensivstationen: Mit oder wegen nosokomialer Infektion?

OBJECTIVE

To describe mortality from intensive care unit acquired infections in German ICUs.

METHODS

The hospital infection surveillance system (KISS = Krankenhaus-Infektions-Surveillance-System) started in Germany in January 1997 as a nationwide surveillance project for the voluntary registration of nosocomial infections. For ICUs reporting focuses on pneumonia and primary bloodstream infections. The data collected for each patient who acquires a nosocomial infection include outcome information. Data of a recent French study and the Statistical Yearbook were used to estimate the annual number of ICU acquired infections contributing to death in Germany.

RESULTS

Data from 897 774 ICU patients were considered for the analysis (January 1997-June 2004). ICU mortality of patients with nosocomial pneumonia was 8.8 %, of patients with primary bloodstream infection was 10,9 %. Of the ICU patients with nosocomial pneumonia and primary bloodstream infections about 3554 die annually, in about 1131 cases the nosocomial infection was the cause of death. It may be estimated that the ICU acquired cases of pneumonia and primary bloodstream infection contributed to the death of about 2400 patients annually in Germany.

CONCLUSION

Because of the substantial mortality of patients with ICU acquired infections preventive measures have a high priority. Further studies leading to improved infection control measures are very wellcome.

[Incidence of transmission of pathogens in intensive care units. Results of the SIR 3 study]

The objective of this study was to determine the incidence of episodes of transmission of nosocomial pathogens and of those pathogens leading to nosocomial infections. Over a period of 18 months all patients from 5 intensive care units (ICUs) who stayed for more than 2 days were included in this study. Surveillance of nosocomial infections was carried out and all isolates of 10 of the most frequent pathogens in ICUs (indicator pathogens) were collected and typed. A total of 28,498 patient days and 431 nosocomial infections were observed (incidence density 15.1 per 1,000 patient days), among them 278 caused by 1 of the selected indicator pathogens. A total of 141 episodes of transmissions were identified, corresponding to an incidence of episodes of transmission of 5.0 per 1,000 patient days and 41 nosocomial infections were transmission-associated, corresponding to 14.5% of all nosocomial infections. The data of this study demonstrate that even in ICUs with average nosocomial infection rates, some nosocomial infections could be avoided.

Surveillance of nosocomial sepsis and pneumonia in patients with a bone marrow or peripheral blood stem cell transplant: a multicenter project

BACKGROUND

For surveillance of nosocomial bloodstream infections (BSIs) and pneumonia during neutropenia in adult patients who have undergone bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT), a multicenter study--the Hospital Infection Surveillance System for Patients with Hematologic/Oncologic Malignancies (ONKO-KISS)--was initiated in Germany in 2000.

METHODS

Nosocomial infections were identified in neutropenic patients by means of Centers for Disease Control and Prevention definitions for laboratory-confirmed BSI and modified criteria for pneumonia.

RESULTS

During the first 38-month period of the study (i.e., through December 2003), a total of 1899 patients associated with 28,273 neutropenic days were investigated. Of these, 1173 (62%) had undergone allogeneic and 726 (38%) had undergone autologous BMT or PBSCT. The mean duration of neutropenia was 14.9 days (9.6 and 18.1 days after autologous and allogeneic transplantation, respectively). Overall, 395 BSIs and 168 cases of pneumonia were identified. The pooled mean site-specific incidence density per 1000 neutropenic days was 14.0 for BSI (12.4 and 18.9 for the allogeneic and autologous transplantation groups, respectively) and 5.9 for pneumonia (6.1 and 5.6 in the allogeneic and autologous transplantation groups, respectively). After allogeneic transplantation, 22.4 BSIs per 100 patients and 11.0 cases of pneumonia per 100 patients occurred, whereas 18.2 BSIs per 100 patients and 5.4 cases of pneumonia per 100 patients occurred after autologous transplantation. The majority (57%) of pathogens associated with BSI were coagulase-negative staphylococci.

CONCLUSIONS

The ongoing ONKO-KISS project provides unprecedented reference data about the incidence of pneumonia and sepsis among BMT recipients and PBSCT recipients in Germany. These data will be used for further evaluation of the impact of hygiene measures and therapeutic regimens for these patients.

Occurrence of organotin compounds in house dust in Berlin (Germany)

In a study in the year 2000 on the occurrence of hazardous environmental contaminants house dust samples from 28 Berlin apartments were measured for the presence and concentrations of six organotin compounds, monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monooctyltin (MOT), dioctyltin (DOT) and triphenyltin (TPT). The concentrations of MBT and DBT determined ranged considerably from 0.01 mg kg-1 to 1.5 mg kg-1 (median: 0.05 mg kg-1) and 0.01 to 5.6 mg kg-1 (median: 0.03 mg kg-1), respectively. Maximum levels of TBT and MOT were only 0.08 mg kg-1 and 0.04 mg kg-1. The maximum total value of the organotins was 7.2 mg kg-1 (median: 0.11 mg kg-1). MBT was found in 86% and DBT in 82% of the samples above the limit of quantification, TBT and MOT only in 50% and DOT in 43%. The focus of ecotoxicology is on the risks arising from organotin compounds (especially butyltins) when used as biocides in antifouling paints. TBT acts as an endocrine disrupter in animals, inducing masculinization (imposex) in female gastropods of different species by increasing testosterone levels. The most critical organ site in experimental animals is the cellular immune system, where lymphocyte depletion in the thymus and peripheral lymphoid tissues takes place. Our study does not provide data on the basis of which population exposure could be estimated; house dust containing harmful organotins could, however, under some conditions, become a relevant intake possibility for young children.

[Surgical site infections in hospitals and outpatient settings. Results of the German nosocomial infection surveillance system (KISS)]

About 1,000,000 hospital days attributable to surgical site infections can be expected per year in German hospitals. Among the various measures for prevention, surveillance of surgical site infections is strongly recommended. Therefore, beginning in 1997 the National Reference Center for Surveillance of Nosocomial Infections began to establish a hospital infection surveillance system in order to provide data for prevention and control of these infections. The surveillance system (called KISS) documents postoperative surgical site infections in patients undergoing selected indicator procedures. Today we have an overview of 274,050 procedures for a total of 20 operative indicator procedures. A further surveillance component focussing on surgical site infections in outpatient settings has recently been developed (AMBU-KISS). The participating hospitals and outpatient settings regularly receive their infection rates as well as the equivalent data of all hospitals involved in order to assess the position of their own hospital. However, competent and meaningful interpretation of these data is necessary for internal quality management in order to avoid wrong conclusions. The available results demonstrate that this approach can lead to a substantial reduction of surgical site infections.

[SARI: surveillance of antibiotic use and bacterial resistance in German intensive care units. Correlation between antibiotic use and the emergence of resistance]

Intensive care units (ICUs) are considered to be high-risk areas for the emergence and spread of multiresistant bacterial pathogens. In Germany, there are no representative epidemiological data on antibiotic resistance, on the use of antibiotics in ICUs, or on the correlation between antibiotic use and the emergence of resistance. Project SARI (surveillance of antibiotic use and bacterial resistance in ICUs), which as a part of the epidemiological network Spread of Nosocomial Infections and Resistant Pathogens (SIR) is supported by the German Ministry of Science and Education, started in February 2000 and meanwhile includes data on antibiotic use and resistance rates in 38 medical, surgical, and interdisciplinary ICUs. To date (February 2000-June 2003), a total of 1142 months, 413,065 patient days, and 550,288 defined daily doses (DDDs in accordance with the WHO) have been covered with a mean antibiotic usage density (AD) of 1335 DDDs/1000 patient days and resistance data on 37,612 isolates from ICUs. Ciprofloxacin use and MRSA correlate significantly, as do imipenem use and the rate of imipenemresistant P. aeruginosa. The genodiversity of P. aeruginosa is lower in ICUs with high resistance rates and low use of imipenem than in ICUs with high resistance rates and high use. This is an indirect parameter of transmission of identical strains. The epidemiological data of SARI form a basis for improved antibiotic and infection control management in ICUs (http://www.sari-antibiotika.de).

Polycyclic aromatic hydrocarbons inside and outside of apartments in an urban area

In the context of environmental monitoring in Berlin polycyclic aromatic hydrocarbon (PAH) concentrations in air and household dust were measured inside 123 residences (and simultaneously in a sub group in the air outside the windows). The aim of this study was to determine exposure to PAHs in the environment influencing by several factors, for instance, motor vehicle traffic in a populous urban area. Indoor air samplings were carried out in two periods (winter and spring/summer) in smokers and non-smokers apartments. Benzo(a)pyrene (BaP) median values were 0.65 ng m(-3) (winter) and 0.27 ng m(-3) (spring/summer) in smokers' apartments and 0.25 ng m(-3) (winter) and 0.09 ng m(-3) (spring/summer) in the apartments of non-smokers. The median BaP content in ambient air was 0.10 ng m(-3) (maximum: 1.1 ng/m(-3)) with an indoor-outdoor mean concentration ratio of 0.9 in non-smoker households and 5.4 in smoker apartments. In household dust we obtained median values of 0.3 mg kg(-1) (range: 0.1-1.4 mg kg(-1)). We found a significant relation between indoor and outdoor values. Approximately 75% of the variance of indoor air values was caused by the corresponding BaP concentrations in the air outside the apartment windows. Otherwise a significant correlation between indoor air and household dust values cannot be found. Therefore, according to our results, it is suggested that the indoor PAH concentration in non-smoker apartments could be attributed mainly to vehicular emissions.

Occurrence of phthalates and musk fragrances in indoor air and dust from apartments and kindergartens in Berlin (Germany)

In this study, the occurrence of persistent environmental contaminants room air samples from 59 apartments and 74 kindergartens in Berlin were tested in 2000 and 2001 for the presence of phthalates and musk fragrances (polycyclic musks in particular). These substances were also measured in household dust from 30 apartments. The aim of the study was to measure exposure levels in typical central borough apartments, kindergartens and estimate their effects on health. Of phthalates, dibutyl phthalate had the highest concentrations in room air, with median values of 1083 ng/m(3) in apartments and 1188 ng/m(3) in kindergartens. With around 80% of all values, the main phthalate in house dust was diethylhexyl phthalate, with median values of 703 mg/kg (range: 231-1763 mg/kg). No statistically significant correlation could be found between air and dust concentration. Musk compounds were detected in the indoor air of kindergartens with median values of 101 ng/m(3) [1,3,4,6,7,8-hexahydro-4,6,6,7,8,8- hexamethylcyclopenta-(g) 2-benzopyrane (HHCB)] and 44 ng/m(3) [7-acetyl-1,1,3,4,4,6-hexamethyl-tetraline (AHTN)] and maximum concentrations of up to 299 and 107 ng/m(3) respectively. In household dust HHCB and AHTN were detected in 63 and 83% of the samples with median values of 0.7 and 0.9 mg/kg (Maximum: 11.4 and 3.1 mg/kg) each. On comparing the above phthalate concentrations with presently acceptable tolerable daily intake values (TDI), we are talking about only a small average intake [di(2-ethylhexyl) phthalate and diethyl phthalate less than 1 and 8% of the TDI] by indoor air for children. The dominant intake path was the ingestion of foodstuffs. For certain subsets of the population, notably premature infants (through migration from soft polyvinyl chloride products), children and other patients undergoing medical treatment like dialysis, exchange transfusion, an important additional intake of phthalates must taken into account.

PRACTICAL IMPLICATIONS

The phthalate and musk compounds load in a sample of apartments and kindergartens were low with a typical distribution pattern in air and household dust, but without a significant correlation between air and dust concentration. The largest source of general population exposure to phthalates is dietary. For certain subsets of the general population non-dietary ingestion (medical and occupational) is important.

Development of a surveillance system for nosocomial infections: the component for neonatal intensive care units in Germany

Neonates are at high risk of nosocomial infections and surveillance has been shown to be valuable for the reduction of nosocomial infections. The National Nosocomial Infections Surveillance (NNIS) system established in the US has a special surveillance component for neonatal intensive care units (NICUs) with some fairly specific methods. However, there are no specific definitions of nosocomial infections in this patient group. When creating a surveillance component for NICUs in Germany we therefore decided not to adopt merely all Centers for Disease Control and Prevention definitions and NNIS methods, but also to develop our own surveillance methods for this patient group. For this process four steps became necessary: (1)development of modified definitions for nosocomial infections and their evaluation; (2)testing the NNIS method in three NICUs with infection control nurses; (3)a pilot project for a surveillance component within the national surveillance system in Germany; and (4)establishment of a surveillance component within our national surveillance system. The system is now established in 33 hospital departments and 66 NICUs participate in the surveillance system. We have an overview of 3357 neonates in three birthweight groups. This article explains the reasons for the various steps, and the advantages and disadvantages of modification of the original NNIS methods and definitions.

Rollen und Aufgaben der Hygienefachkr�fte und des Krankenhaushygienikers unter besonderer Ber�cksichtigung von Kosten-Nutzen-Aspekten

In the past it was a guiding principle of hospital epidemiologists and infection control practitioners to compare the particular standards prevailing in their hospitals with the regulations, directives, and guidelines laid down by law and then to aim for some change. However, if we are to ever really achieve a reduction in nosocomial infections, it will be necessary to sensitize all hospital personnel to the problems associated with such infections and to convince them of the unavoidability of having to introduce specific new measures. Accordingly, surveillance of nosocomial infections and multiresistant pathogens, analysis of possible infection-associated problems, and initiating appropriate intervention procedures are indispensable goals for hospital hygiene if a decrease in nosocomial infections is to be realized. It would be possible to thus reduce expenditures representing more than the present costs for the hygiene staff. On the strength of their thorough specialist knowledge of the spread of nosocomial infections, it is also part of the responsibilities of infection control practitioners and hospital epidemiologists to question and to do away with senseless preventive measures and thereby contribute to reducing hospital expenditures.

Der Beitrag von Ausbruchanalysen zur Pr�vention nosokomialer Infektionen

Outbreaks of nosocomial infections can be associated with significant morbidity in the patients involved and require time, effort, and resources. In addition, they may lead to panic reactions among health care workers and patients as well as the community. However, their systematic analysis can contribute to knowledge about the sources and transmission of nosocomial infections and the best methods for prevention. Furthermore, the results of outbreak investigations may serve as a valuable tool for education. That is why a systematic register of nosocomial outbreaks would be a very useful instrument for people working in the field of nosocomial infection control. This article describes the need for a systematic collection of outbreaks published in the literature and an available possibility for filling this gap.

[Microbiological isolates associated with nosocomial infections in intensive care units: data of 274 intensive care units participating in the German Nosocomial Infections Surveillance System (KISS)]

OBJECTIVE

To describe the frequency and distribution of microbiological isolates in association with nosocomial infections (NI) in intensive care units (ICUs) in Germany.

METHODS

The hospital infection surveillance system (KISS = Krankenhaus-Infektions-Surveillance-System) started in Germany in January 1997 as a nationwide surveillance project for the voluntary registration of nosocomial infections. For ICUs reporting focuses on device-associated primary bloodstream infections, urinary tract infections, as well as on pneumonia and bronchitis. The data collected for each patient who acquires a nosocomial infection include the site of infection and patient demographics. Up to 4 pathogens can be recorded for each infection.

RESULTS

From 1997 until 2002 274 ICUs were participating. The data of 590 695 patients with 18 073 device associated infections (ventilator-associated pneumonia and bronchitis, central line-associated bloodstream infection (BSI) and urinary catheter-associated urinary tract infection (UTI)) were analyzed. In the group of device-associated NI S. aureus was most frequently isolated (16.5/100NI) followed by Ps. aeruginosa (14.2/100NI), E. coli (13.9/100NI), enterococci (13.4/100NI) and C. albicans (11.2/100NI). Of all S. aureus isolates 20.0 % were MRSA. There was an increase of the MRSA rate from 8 % in 1997 to 26.9 % in 2002. The most frequent pathogen in BSI was coagulase-negative staphylococcus (31.0/100NI). In ventilator-associated pneumonia and bronchitis S. aureus was the most frequent pathogen (24.2 and 24.9/100NI). In more than half of all catheter-associated UTI E. coli (25.7/100NI) and enterococci (25.4/100NI) were found. After stratification for the type of ICU differences in the distribution of pathogens could be shown.

CONCLUSIONS

The KISS data give an overview of the most important pathogens associated with nosocomial infections on ICUs in Germany.

[Quality assurance in intensive care medicine. SARI-surveillance on antibiotic use and bacterial resistance in intensive care units]

Intensive care units (ICUs) are high risk areas for emergence and spread of multiresistant bacterial pathogens. In Germany, there are no representative epidemiological data on antibiotic resistance, prophylactic or therapeutic use of antibiotics in ICUs, or on the correlation between antibiotic use and emergence of resistance. Supported by the German Ministry of Science and Education, project SARI (Surveillance on antibiotic use and bacterial resistance in ICUs) started in 02/2000 and now includes data on antibiotic use and resistance rates in 35 medical, surgical and interdisciplinary ICUs. To date (2/2000-12/2002), a total of 939 participant months, 339,461 patient days and 452,282 defined daily doses (DDD) have been covered with a mean antibiotic usage density (AD) of 1,332 DDDs/1,000 patient days and resistance data on 31,189 isolates from ICUs. The design of the project and first results of SARI are presented. The epidemiological data of SARI form a basis for improved antibiotic and infection control management in ICUs (http://www.sari-antibiotika.de).