[Tuberculosis infection control - recommendations of the DZK]. / Infektionsprävention bei Tuberkulose - Empfehlungen des 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]. / Infektionsprävention bei Tuberkulose--Empfehlungen des 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.

Wide dissemination of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella spp. in acute care and rehabilitation hospitals.

A prospective surveillance system for extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E) and ESBL-producing Klebsiella spp. (ESBL-K) was implemented in 39 German hospitals with the aim of determining the incidence densities (IDs) of community-onset and hospital-onset cases and of identifying risk factors for high IDs of hospital-onset cases. During 2008, 2081 ESBL-E/K cases were documented. ESBL-E cases (n=1330, 63·9%) were more common than ESBL-K cases (n=751, 36·1%), but a higher proportion of ESBL-K cases (59%) than of ESBL-E cases (39·5%) were hospital-onset cases. The mean IDs were 0·54 (range 0-2·53) per 1000 patient-days for all ESBL-EK cases, 0·29 (range 0-1·81) per 1000 patient-days for community-onset ESBL-EK cases and 0·25 (range 0-1·82) per 1000 patient-days for hospital-onset ESBL-EK cases. Regression analysis showed a linear association between the IDs of community-onset and hospital-onset cases. The wide dissemination of ESBL-E and ESBL-K emphasizes the need for hospital-wide surveillance to guide control measures.

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.

[Diversity in antibiotic use in intensive care units in Germany]. / Diversität des Antibiotikaverbrauchs auf Intensivstationen in Deutschland.

INTRODUCTION: The aim of the study was to present data from the SARI study (Surveillance of Antibiotic Use and Bacterial Resistance in Intensive Care Units) on antibiotic use in Intensive care Units (ICU) in Germany and to determine parameters responsible for involved in the diversity of antibiotic usage. METHODS: Antibiotic administration in 43 intensive care units in Germany was recorded. Antibiotic usage density (AD) was measured: it describes the use of antibiotics and is expressed as defined daily doses (DDD) and is normalized per 1000 patient-days (pd). Prescribing parameters were the number of antibiotics administered, the amount of the most frequently used antibiotics as a percentage of total antibiotic use and the percentage of selected antibiotic groups as part of total use. RESULTS: Median antibiotic use was 1156 DDDs per 1000 patient-days in the year 2005. However, antibiotic administration was very heterogeneous and ranged from 450 to 1 799 DDDs/1 000 pd. There was no statistically significant association between total use and status or type of hospital and type of ICU. Use of antibiotic groups was also heterogeneous: if pooled data are taken, penicillins and cephalosporins each accounting for a quarter of total antibiotic use. In individual ICUs the use of quinolones was more than 35% of all drugs given, 3rd and 4th generation cephalosporins almost 40% and carbapenems up to 30%. The most frequently used antibiotic per ICU made up 17% (median) of total antibiotic use, the three most frequently administered antibiotics accounting for up to 40%. CONCLUSION: The great heterogeneity of antibiotic use may indicate room for improvement. Prescribing parameters such as the percentage of antibiotic groups among total antibiotic usage provide additional information on the selective pressure of antibiotics used in the ICU beyond quantitative data on drug administration.

An outbreak of hospital-acquired Pseudomonas aeruginosa infection caused by contaminated bottled water in intensive care units.

This study describes an outbreak of Pseudomonas aeruginosa infections caused by contaminated bottled still water (BSW) in six intensive care units (ICUs) of a German university hospital. Clinical and environmental samples from these units were cultured and genotyped by amplified fragment-length polymorphism and pulsed-field gel electrophoresis analysis. Microbiological results were reviewed on a weekly basis to determine the number of P. aeruginosa infections and colonisations of ICU patients. Clinical specimens from 19 ICU patients--15 infections and four colonisations--yielded the same strain of P. aeruginosa. Furthermore, four of 103 environmental samples also yielded P. aeruginosa. However, only a P. aeruginosa strain isolated from unopened BSW was genetically identical to the P. aeruginosa strain isolated from the patients. In the 42-week period before the outbreak, the mean weekly number of new ICU patients infected or colonised with P. aeruginosa was 46.9 (95% CI 40.7-53.1)/1000 bed-days. During the 6-week period of the outbreak, the weekly number of new patients with P. aeruginosa was 88.9 (95% CI 54.3-122.2)/1000 bed-days. This number returned to the previous level after removal of the BSW. Thus, the microbiological and epidemiological findings revealed that the outbreak was related to BSW contaminated with P. aeruginosa. It was concluded that all untested BSW should be removed from ICUs.

Time-trends for Gram-negative and multidrug-resistant Gram-positive bacteria associated with nosocomial infections in German intensive care units between 2000 and 2005.

This study analysed the time-trends for bacteria associated with nosocomial lower respiratory tract infections (LRTIs), bloodstream infections (BSIs) and urinary tract infections (UTIs) that were reported to the German Nosocomial Infection Surveillance System for intensive care units (ICUs). Data concerning 19 822 nosocomial infections were submitted by 139 ICUs between 2000 and 2005. There was a significant increase in the proportion of Gram-negative bacteria causing LRTIs (from 63.9% to 68.4%) and UTIs (from 65.3% to 68.6%). The proportion of BSIs caused by Gram-negative bacteria declined significantly, from 36.4% to 22.7%. The frequency of methicillin-resistant Staphylococcus aureus among all S. aureus isolates increased from 19.8% to 37.2%.

[Costs due to urinary tract infections in Germany. An estimation based on the data from the German National Nosocomial Infections Surveillance System]. / Kosten durch Harnweginfektionen in Deutschland. Eine Hochrechung der Daten des Krankenhaus-Infektions-Surveillance-Systems.

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.

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.

[Surgical site infection rates using a laparoscopic approach: results of the German national nosocomial infections surveillance system]. / Wundinfektionen nach laparoskopischen Operationen: Ergebnisse des Krankenhaus-Infektions-Surveillance-Systems.

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.

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.

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 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.

Validation of surveillance in the intensive care unit component of the German nosocomial infections surveillance system.

A validation study was performed for the intensive care unit component of the German nosocomial infections surveillance system (Krankenhaus Infektions Surveillance System [KISS]). A total of 286 reported infections and 1,195 medical records with no reported infection from 20 randomly selected KISS intensive care units were reviewed by trained physicians. The mean sensitivity was 66% (median, 81%), and the mean specificity was 99.4% (median, 99.6%).

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 chi (2) 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 chi (2) 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.

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.

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.

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.