Colonization with third-generation cephalosporin-resistant Enterobacteriaceae on hospital admission: prevalence and risk factors.

OBJECTIVES: The objectives of this study were to prospectively assess the rectal carriage rate of third-generation cephalosporin-resistant Enterobacteriaceae (3GCREB) in non-ICU patients on hospital admission and to investigate resistance mechanisms and risk factors for carriage. METHODS: Adult patients were screened for 3GCREB carriage at six German tertiary care hospitals in 2014 using rectal swabs or stool samples. 3GCREB isolates were characterized by phenotypic and molecular methods. Each patient answered a questionnaire about potential risk factors for colonization with MDR organisms (MDROs). Univariable and multivariable risk factor analyses were performed to identify factors associated with 3GCREB carriage. RESULTS: Of 4376 patients, 416 (9.5%) were 3GCREB carriers. Escherichia coli was the predominant species (79.1%). ESBLs of the CTX-M-1 group (67.3%) and the CTX-M-9 group (16.8%) were the most frequent ß-lactamases. Five patients (0.11%) were colonized with carbapenemase-producing Enterobacteriaceae. The following risk factors were significantly associated with 3GCREB colonization in the multivariable analysis (P < 0.05): centre; previous MDRO colonization (OR = 2.12); antibiotic use within the previous 6 months (OR = 2.09); travel outside Europe (OR = 2.24); stay in a long-term care facility (OR = 1.33); and treatment of gastroesophageal reflux disease (GERD) (OR = 1.22). CONCLUSIONS: To our knowledge, this is the largest admission prevalence study of 3GCREB in Europe. The observed prevalence of 9.5% 3GCREB carriage was higher than previously reported and differed significantly among centres. In addition to previously identified risk factors, the treatment of GERD proved to be an independent risk factor for 3GCREB colonization.

Epidemiology of healthcare associated infections in Germany: Nearly 20 years of surveillance.

OBJECTIVE: To describe the epidemiology of healthcare-associated infections (HAI) in hospitals participating in the German national nosocomial infections surveillance system (KISS). METHOD: The epidemiology of HAI was described for the surveillance components for intensive care units (ITS-KISS), non-ICUs (STATIONS-KISS), very low birth weight infants (NEO-KISS) and surgical site infections (OP-KISS) in the period from 2006 to 2013. In addition, risk factor analyses were performed for the most important infections of ICU-KISS, NEO-KISS and OP-KISS. RESULTS: Data from a total of 3,454,778 ICU patients from 913 ICUs, 618,816 non-ICU patients from 142 non-ICU wards, 53,676 VLBW from 241 neonatal intensive care units (NICU) and 1,005,064 surgical patients from operative departments from 550 hospitals were used for analysis. Compared with baseline data, a significant reduction of primary bloodstream infections (PBSI) and lower respiratory tract infections (LRTI) was observed in ICUs with the maximum effect in year 5 (or longer participation) (incidence rate ratio 0.60 (CI95 0.50-0.72) and 0.61 (CI95 0.52-0.71) respectively). A significant reduction of PBSI and LRTI was also observed in NEO-KISS when comparing the baseline situation with the 5th year of participation (hazard ratio 0.70 (CI95 0.64-0.76) and 0.43 (CI95 0.35-0.52)). The effect was smaller in operative departments after the introduction of OP-KISS (OR 0.80; CI95 0.64-1.02 in year 5 or later for all procedure types combined). Due to the large database, it has not only been possible to confirm well-known risk factors for HAI, but also to identify some new interesting risk factors like seasonal and volume effects. CONCLUSIONS: Participating in a national surveillance system and using surveillance data for internal quality management leads to substantial reduction of HAI. In addition, a surveillance system can identify otherwise not recognized risk factors which should - if possible - be considered for infection control management and for risk adjustment in the benchmarking process.

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

PURPOSE: 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. METHODS: 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). RESULTS: 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). CONCLUSIONS: 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.

Occurrence and trends of Clostridioides difficile infections in hospitalized patients: a prospective multi-centre cohort study in six German university hospitals, 2016-2020.

BACKGROUND: For Clostridioides difficile infections (CDIs) in Germany no longitudinal multi-centre studies with standardized protocols for diagnosing CDI are available. Recent evaluations of general surveillance databases in Germany indicate a downward trend in CDI rates. We aimed to describe the actual burden and trends of CDI in German university hospitals from 2016 to 2020. METHODS: Our study was a prospective multi-centre study covering six German university hospitals. We report the data in total, stratified by year, by medical specialty as well as by CDI severity. Multi-variable regression analyses were performed to assess risk factors for severe CDI. RESULTS: We registered 3780 CDI cases among 1,436,352 patients. The median length of stay (LOS) of CDI cases was 20 days (interquartile range 11-37) compared with a general LOS of 4.2 days. In-hospital all-cause mortality in CDI patients was 11.7% (N = 444/3780), while mortality attributed to CDI was 0.4% (N = 16/3761). CDI recurrence rate was comparatively low at 7.2%. The incidence density of severe healthcare-associated healthcare onset (HAHO)-CDI showed a significant decrease from 2.25/10,000 patient days (pd) in 2016 to 1.49/10,000 pd in 2020 (trend calculation P=0.032). CONCLUSIONS: Compared with a European point-prevalence study in 2013/2014, where overall CDI incidence density was 11.2 cases/10,000 pd in Germany (EUCLID), we see in our study halved overall CDI rates of 5.6 cases/10,000 pd in 2020. Our study shows current data on the distribution of CDI cases in German university hospitals and thus provides international comparative data on the key indicators of CDI.

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

BACKGROUND: 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. AIM: To investigate whether sinks in ICU patient rooms are associated with a higher incidence of hospital-acquired infection (HAI). METHODS: 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). FINDINGS: 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). CONCLUSIONS: 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.

Analysis of transmission-related third-generation cephalosporin-resistant Enterobacterales by electronic data mining and core genome multi-locus sequence typing.

BACKGROUND: To contain intra-hospital transmission of third-generation cephalosporin-resistant Enterobacterales (3GCR-E), contact isolation precautions are recommended. AIM: To quantify transmissions of 3GCR Escherichia coli and 3GCR Klebsiella pneumoniae within a hospital. METHODS: An automated outbreak detection system (AODS) was used to identify clusters (N≥2) of 3GCR Enterobacterales for the years 2016, 2018 and 2020. Clusters were defined by phenotypic agreement of microbiological results and spatial and temporal relationship. Core genome multi-locus sequence typing (cgMLST) was used to confirm whether the cluster isolates were transmitted between patients. FINDINGS: A total of 4343 3GCR E. coli and 1377 K. pneumoniae isolates were analysed. Among the 3GCR E. coli isolates, the AODS identified 304 isolates as cluster isolates, the median cluster size was two (range: 2-5). The cgMLST analysis revealed that a total of 23 (7.5%) 3GCR E. coli cluster isolates were transmission-associated, of which 20 isolates (87%) were detected in intensive care patients. Among the 3GCR K. pneumoniae isolates, the AODS identified 73 isolates as cluster isolates, the median cluster size was two (range: 2-4). CgMLST revealed that 35 (48%) 3GCR K. pneumoniae cluster isolates were transmission associated, of which 27 isolates (77%) were detected in intensive care patients. CONCLUSION: For 3GCR K. pneumoniae, cgMLST confirmed the AODS results more frequently than for 3GCR E. coli. Therefore, contact isolation precautions for 3GCR K. pneumoniae may be appropriate on intensive care units, but only in certain circumstances, such as outbreaks, for Enterobacterales with lower transmissibility, such as E. coli.

[Healthcare-associated infection rates: measuring and comparing. Experiences from the German National Nosocomial Infection Surveillance System (KISS) and from other surveillance systems]. / Nosokomiale Infektionsraten: Messen und Vergleichen. Erfahrungen mit dem Krankenhaus-Infektions-Surveillance-System (KISS) und anderen Surveillance-Systemen.

Surveillance of nosocomial infections is meanwhile a cornerstone of infection prevention activities in hospitals. The objective of this article is to compare healthcare-associated infection rates in intensive care patients, neonatal intensive care patients and operated patients (ICU-KISS, OP-KISS, NEO-KISS) of the German nosocomial infection surveillance system (KISS) with the corresponding data of the US American National Healthcare Safety Network (NHSN) and the European Centre for Disease Prevention and Control (ECDC). In general, the methodological differences among the three surveillance systems are minor but there are some exceptions. Therefore, differences between countries have to be interpreted very carefully as they may be due to differences in diagnostics, patient mix, types of interventions, length of stay, selection of participating hospitals, post-discharge surveillance activities and interpretation of case definitions. Organizational aspects, such as mandatory participation with public disclosure on infection rates may also have an impact.

Automated surveillance systems for healthcare-associated infections: results from a European survey and experiences from real-life utilization.

BACKGROUND: As most automated surveillance (AS) methods to detect healthcare-associated infections (HAIs) have been developed and implemented in research settings, information about the feasibility of large-scale implementation is scarce. AIM: To describe key aspects of the design of AS systems and implementation in European institutions and hospitals. METHODS: An online survey was distributed via e-mail in February/March 2019 among (i) PRAISE (Providing a Roadmap for Automated Infection Surveillance in Europe) network members; (ii) corresponding authors of peer-reviewed European publications on existing AS systems; and (iii) the mailing list of national infection prevention and control focal points of the European Centre for Disease Prevention and Control. Three AS systems from the survey were selected, based on quintessential features, for in-depth review focusing on implementation in practice. FINDINGS: Through the survey and the review of three selected AS systems, notable differences regarding the methods, algorithms, data sources, and targeted HAIs were identified. The majority of AS systems used a classification algorithm for semi-automated surveillance and targeted HAIs were mostly surgical site infections, urinary tract infections, sepsis, or other bloodstream infections. AS systems yielded a reduction of workload for hospital staff. Principal barriers of implementation were strict data security regulations as well as creating and maintaining an information technology infrastructure. CONCLUSION: AS in Europe is characterized by heterogeneity in methods and surveillance targets. To allow for comparisons and encourage homogenization, future publications on AS systems should provide detailed information on source data, methods, and the state of implementation.

Worldwide Outbreak Database: the largest collection of nosocomial outbreaks.

Epidemiological findings of a single outbreak event may not be generalized; however, the characteristics of a typical outbreak can be determined on the basis of a large number of similar events. The Outbreak Database ( http://www.outbreak-database.com ) is the largest collection of nosocomial outbreaks currently available-and is still expanding. Articles are filed systematically, enabling those on a specific parameter of interest to be retrieved quickly. As such, this database is an extremely valuable tool on many medically related fronts, such as for educating other medical personnel, providing relevant information during the investigation of an acute outbreak, or addressing scientific-oriented questions. Several systematic reviews on a wide range of subjects, including sources of infections, types of pathogens, routes of transmission, appropriate infection control measures, and patients at risk of infection, have already been published based on information contained in this database. As this database may be used free of charge, all medical staff in the field of infection control, hygiene, and hospital epidemiology should be aware of its existence.

Prolonged duration of operation: an indicator of complicated surgery or of surgical (mis)management?

PURPOSE: The aim of this study was to investigate whether a prolonged operative time should be regarded as an indicator of quality problems in operating rooms or as patient-specific risk factors when analyzing surgical site infection (SSI) rates. METHOD: Data from the SSI component of the German national nosocomial infection surveillance system (KISS) were used to address this question. Eight procedure categories tracked by at least 30 departments participating in KISS were included in the analysis, namely, hip (2 types) and knee prosthesis, breast surgery, hernia repair, C-section, cholecystectomy and colon operations. Various multiple logistic regression analyses were performed for each procedure category to predict duration of operation. Patient factors (sex, age, American Society of Anesthesiologists score, wound contamination class) and hospital factors (hospital status, size, annual volume) were considered. The area under the receiver operating characteristic (ROC) curve was used to evaluate predictive power including patient- and hospital-based factors. RESULTS: A total of 253,454 operations were included in the analysis. In general, the predictive power of the model including all variables for the different procedure types was relatively low (C-index range: 0.57-0.63) and not much higher than that of the models including only patient-based or only hospital-based variables, respectively. The predictive power for the duration of operative time based on the model including only hospital-based variables was as good as or better than that of the model including only patient-based factors. CONCLUSION: Duration of operation is at least partially determined by hospital factors and, consequently, should be used as a quality indicator to compare SSI infections between hospitals, rather than being used as a patient factor to adjust comparisons between hospitals.

Radiolabelling of engineered nanoparticles for in vitro and in vivo tracing applications using cyclotron accelerators.

We present in this article an outline of some cyclotron-based irradiation techniques that can be used to directly radiolabel industrially manufactured nanoparticles, as well as two techniques for synthesis of labelled nanoparticles using cyclotron-generated radioactive precursor materials. These radiolabelled nanoparticles are suitable for a range of different in vitro and in vivo tracing studies of relevance to the field of nanotoxicology. A basic overview is given of the relevant physics of nuclear reactions regarding both ion-beam and neutron production of radioisotopes. The various issues that determine the practicality and usefulness of the different methods are discussed, including radioisotope yield, nuclear reaction kinetics, radiation and thermal damage, and radiolabel stability. Experimental details are presented regarding several techniques applied in our laboratories, including direct light-ion activation of dry nanoparticle samples, neutron activation of nanoparticles and suspensions using an ion-beam driven activator, spark-ignition generation of nanoparticle aerosols using activated electrode materials, and radiochemical synthesis of nanoparticles using cyclotron-produced isotopes. The application of these techniques is illustrated through short descriptions of some selected results thus far achieved. It is shown that these cyclotron-based methods offer a very useful range of options for nanoparticle radiolabelling despite some experimental difficulties associated with their application. For direct nanoparticle radiolabelling, if care is taken in choosing the experimental conditions applied, useful activity levels can be achieved in a wide range of nanoparticle types, without causing substantial thermal or radiation damage to the nanoparticle structure. Nanoparticle synthesis using radioactive precursors presents a different set of issues and offers a complementary and equally valid approach when laboratory generation of the nanoparticles is acceptable for the proposed studies, and where an appropriate radiolabel can be incorporated into the nanoparticles during synthesis.

[Less blood culture samples: less infections?]. / Wenige Blutkulturproben - wenige Infektionen?

BACKGROUND: The data of the German hospital nosocomial infection surveillance system (KISS) were used to investigate the association between the frequency of blood cultures (BC) and central venous catheter associated bloodstream infection (CVC-BSI) rates in intensive care units (ICU). METHODS: A questionnaire on the frequency of BCs taken was sent to all ICUs participating in KISS and univariable and multivariable analyses were performed on the results. RESULTS: A total of 223 ICUs provided data. The median number of BC pairs taken in 2006 was 60 with a huge variation from 3.2 to 680 per 1,000 patient days. The mean primary BSI rate was 0.90 per 1,000 patient days and 0.25 BSIs per 1,000 patient days were caused by coagulase negative Staphylococci (CNS). The mean CVC-BSI rate was 1.40 per 1,000 CVC days. In the univariable analysis the blood culture frequency had a significant influence on the CVC-associated BSI rate, considering either all pathogens (p=0.001) or only the subgroup of CNS-related cases (p=0.019). There was also a significant influence of the BC frequency on the CVC-BSI rate considering all pathogens (p=0.004) as well as the subgroup of CNS (p=0.018). Therefore the BC frequency was a significant factor affecting the incidence of BSI and CVC-BSI. According to the multivariable analysis an increase of the BC frequency of 100 BCs per 1,000 patient days leads to a 1.27-fold higher incidence density of CVC-BSI with a 95% confidence interval (95% CI) of 1.01-1.26. A further significant risk factor for CVC-BSI was the length of stay in the ICU with an adjusted incidence rate ratio (IRR) of 1.25 (95% CI 1.15-1.35). To have the status of an interdisciplinary ICU was a significant protective factor (IRR 0.64; 95% CI 0.45-0.92). CONCLUSIONS: If an external benchmarking of ICU CVC-BSI rates is intended an adjustment according to the BC frequency is necessary. The BC frequency itself should be established as a quality indicator in intensive care.

[Quality management for preventing healthcare-acquired infections. The importance of surveillance]. / Qualitätsmanagement zur Infektionsprävention im Krankenhaus. Die Bedeutung der Surveillance.

Healthcare acquired (nosocomial) infections are one of the most frequent complications of medical care. The management to prevent such nosocomial infections is a typical example of the use of the general principles of quality management in healthcare institutions: each institution should compare their own nosocomial infection rates for defined patient risk groups with reference data and identify problems concerning specific infection types or units/departments. This comparison should stimulate a careful analysis of the process of care and the options to improve the situation. Structured interventions, such as the introduction of bundles of infection control measures or checklists, are very helpful to increase compliance with infection control measures and to decrease nosocomial infection rates. However, often only interventions individually designed according to the specific needs in a particular unit/department are successful to improve infection rates. Therefore, the employment of experienced infection control personnel and surveillance strategies designed according to the specific needs of the institution are key elements of a good infection control management within healthcare institutions.

Management of peripheral venous catheters and implementation of guidelines in Germany: a national survey.

BACKGROUND: Due to their frequent use, peripheral venous catheters (PVCs) are of importance in terms of catheter-related infections and their prevention. In 2017, revised national guidelines for the prevention of PVC-related infections were published in Germany. AIM: To describe PVC handling practices and assess the implementation of national guidelines for the prevention of PVC-related infections in German acute care hospitals, 10 months after their release. METHODS: An online survey on the management of PVCs in hospital wards was conducted. For this, 1191 acute care hospitals participating in the national surveillance system for healthcare-associated infections in Germany were invited to participate. Each hospital was asked to complete the survey for an intensive care unit (ICU), as well as a medical ward and a surgical ward. Participation in the survey was voluntary. FINDINGS: In total, 701 hospitals (response rate 59%) participated and provided data on 1449 wards (599 ICUs, 446 medical wards, 404 surgical wards). Approximately 43% of wards reported that they had implemented the new national guidelines where necessary. Structured surveillance for PVC-associated infections was established in only 21% of wards. While 94% of wards reported the inclusion of aspects of PVC handling in their general infection prevention education, questions on the training methods yielded diverse results. Approximately 59% of wards reported that they did not routinely use a combination of alcohol and a remanant disinfectant for skin disinfection before PVC insertion. CONCLUSION: Generally, PVC management in Germany is well organized. However, potential for improvement was identified, particularly considering surveillance and implementation of selected national guidelines.

No increase in compliance before aseptic procedures in German hospitals. A longitudinal study with data from the national surveillance system over four years.

BACKGROUND: Hand hygiene plays a crucial role in the prevention of healthcare-associated infections and transmission of pathogens. In 2008 the national campaign 'Aktion Saubere Hände' was launched in Germany. It is based on the World Health Organization (WHO) 'Clean Care is Safer Care' initiative. Direct observation and feedback of the results are key components in the improvement of hand hygiene compliance. In 2014 a voluntary national surveillance electronic tool for the documentation of directly observed compliance to hand hygiene was introduced. AIM: Description and evaluation of compliance with the WHO model 'my 5 moments' in German hospitals after implementation. METHODS: Direct observation was performed in the participating hospitals by trained local staff according to the WHO recommendations. We evaluated wards that reported annually at least 150 hand hygiene opportunities (HHOs) of hand hygiene per observation period from January 1st, 2015 until December 31st, 2018. FINDINGS: In all, 1,485,622 HHOs observed on 3337 wards in 525 hospitals were included into analysis. Overall compliance increased from 72% (interquartile range: 61-82) to 76% (66-84). Compliance significantly increased for all individual moments of the WHO model except moment 2. In the multivariate logistic regression analysis the following parameters were independently associated with a high compliance in hand hygiene: intensive care unit, nurse, opportunity observed in 2017 or 2018, as well as all moments except moment 2. CONCLUSION: Overall compliance in German hospitals increased over time. To improve HH compliance 'before aseptic procedures' appears to be difficult and should be addressed explicitly. Underlying reasons need to be the focus of future investigations.

National influences on catheter-associated bloodstream infection rates: practices among national surveillance networks participating in the European HELICS project.

This study was performed to evaluate associations between organisational characteristics, routine practices and the incidence densities of central venous catheter-associated bloodstream infections (CVC-BSI rates) in European intensive care units (ICUs) as part of the HELICS project (Hospitals in Europe Link for Infection Control through Surveillance). Questionnaires were sent to ICUs participating in the national nosocomial infection surveillance networks in 2004. The national networks were asked for the CVC-BSI rates of the ICUs participating for the time period 2003--2004. Univariate and multivariate risk factor analyses were performed to identify which practices had the greatest impact on CVC-BSI rates. A total of 526 ICUs from 10 countries sent data on organisational characteristics and practices, demonstrating wide variation in care. CVC-BSI rates were also provided for 288 ICUs from five countries. This made it possible to include 1383444 patient days, 969897 CVC days and 1935 CVC-BSI cases in the analysis. Adjusted logistic regression analysis showed that the categorical variables of country [odds ratio (OR) varying per country from OR: 2.3; 95% confidence interval (CI): 0.5-10.2; to OR: 12.8; 95% CI: 4.4-37.5; in reference to the country with the lowest CVC-BSI rates] and type of hospital 'university' (OR: 2.08; 95% CI: 1.02-4.25) were independent risk factors for high CVC-BSI rates. Substantial variation existed in CVC-BSI prevention activities, surveillance methods and estimated CVC-BSI rates among the European countries. Differences in cultural, social and legal perspectives as well as differences between healthcare systems are crucial in explaining these differences.

Dosimetry and toxicology of inhaled ultrafine particles.

Both epidemiological and toxicological studies indicate that inhalation and subsequent deposition of airborne particles into the lungs have adverse health effects. Recently, the ultrafine particle (UfP) fraction (diameter < 100 nm) has received particular attention, as their small size may lead to more toxic properties. In this study we summarize the current knowledge on the dosimetry of inhaled particles (including UfPs) with a focus on recent data on translocation of UfPs into secondary target organs (such as brain and heart) suggesting that the lifetime dose of ambient UfPs in secondary target organs is about 10(11) particles. Furthermore, we highlight the main pathways of particle induced toxicity and the reasons for the potentially higher toxicity of UfPs. Finally, we discuss recent evidence indicating that (BET) surface area is the single most relevant dose metric for the toxicity of UfPs, which has important implications for regulatory measures on the toxicity of ambient and engineered particles.

Decrease of methicillin resistance in Staphylococcus aureus in nosocomial infections in Germany-a prospective analysis over 10 years.

OBJECTIVES: Methicillin resistant Staphylococcus aureus (MRSA) remains an important cause of healthcare-associated infections. Here, we describe the development of methicillin-resistant isolates among nosocomial Staphylococcus aureus (SA) infections in Germany between 2007 and 2016. METHODS: We analyzed data from the voluntary German national nosocomial Infection Surveillance System. Data on bloodstream infections (BSI) and lower respiratory tract infections (LRTI) were derived from intensive care units (ICU), whereas data on surgical site infections (SSI) were collected from surgical departments (SD). Univariate analysis was performed on trend of proportion, while multivariable logistic regression was performed to identify risk factors for MRSA-infections. RESULTS: Data of 1218 ICU and 1,556 SD were included. Overall, a decrease in the proportion of MRSA among all nosocomial SA-infections from 32.8% to 20.0% was noted. MRSA decreased from 37.1% to 21.8% (p = 0.01) for BSI, from 38.7% to 19.2% for LTRI (p < 0.01) and. from 21.1% to 7.4% (p < 0.01) in SSI. Logistic regression revealed that SA-infections in Mecklenburg Western-Pomerania were more likely caused by MRSA (Odds ratio (OR): 2.5; 95% CI: 1.7, 3.6). CONCLUSION: We observed a significant reduction of the proportion of nosocomial Staphylococcus aureus infections due to MRSA in Germany over the course of the last 10 years.

Impact of participation in a surgical site infection surveillance network: results from a large international cohort study.

BACKGROUND: Surveillance of surgical site infections (SSIs) is a core component of effective infection control practices, though its impact has not been quantified on a large scale. AIM: To determine the time-trend of SSI rates in surveillance networks. METHODS: SSI surveillance networks provided procedure-specific data on numbers of SSIs and operations, stratified by hospitals' year of participation in the surveillance, to capture length of participation as an exposure. Pooled and procedure-specific random-effects Poisson regression was performed to obtain yearly rate ratios (RRs) with 95% confidence intervals (CIs), and including surveillance network as random intercept. FINDINGS: Of 36 invited networks, 17 networks from 15 high-income countries across Asia, Australia and Europe participated in the study. Aggregated data on 17 surgical procedures (cardiovascular, digestive, gynaecological-obstetrical, neurosurgical, and orthopaedic) were collected, resulting in data concerning 5,831,737 operations and 113,166 SSIs. There was a significant decrease in overall SSI rates over surveillance time, resulting in a 35% reduction at the ninth (final) included year of surveillance (RR: 0.65; 95% CI: 0.63-0.67). There were large variations across procedure-specific trends, but strong consistent decreases were observed for colorectal surgery, herniorrhaphy, caesarean section, hip prosthesis, and knee prosthesis. CONCLUSION: In this large, international cohort study, pooled SSI rates were associated with a stable and sustainable decrease after joining an SSI surveillance network; a causal relationship is possible, although unproven. There was heterogeneity in procedure-specific trends. These findings support the pivotal role of surveillance in reducing infection rates and call for widespread implementation of hospital-based SSI surveillance in high-income countries.