Operating room ventilation with laminar airflow shows no protective effect on the surgical site infection rate in orthopedic and abdominal surgery.

OBJECTIVE: To evaluate whether operating room (OR) ventilation with (vertical) laminar airflow impacts on surgical site infection (SSI) rates. DESIGN: Retrospective cohort-study based on routine surveillance data. PATIENTS AND METHODS: Sixty-three surgical departments participating voluntarily in the German national nosocomial infections surveillance system "KISS" were included (a total of 99,230 operations). Active SSI surveillance was performed according to the methods and definitions given by the US National Nosocomial Infection Surveillance system. Surgical departments were stratified according to type of OR ventilation used: (1) turbulent ventilation with high-efficiency particulate air-filtered air, and (2) HEPA-filtered (vertical) laminar airflow ventilation. Multivariate analyses were performed by the generalized estimating equations method to control for the following variables as possible confounders: (a) Patient-based: wound contamination class, ASA score, operation duration, patients' age and gender, endoscopic operation; (b) Hospital-based: the number of beds in the hospital, its academic status, operation frequency, and long-term participation in KISS. RESULTS: The risk for severe SSI after hip prosthesis implantation was significantly higher using laminar airflow OR ventilation (1.63 < 1.06; 2.52>), as compared with turbulent ventilation. The adjusted odds ratios for the other operative procedures analyzed were: knee prosthesis 1.76 < 0.80, 3.85>; appendectomy 1.52 < 0.91, 2.53>; cholecystectomy 1.37 < 0.63, 2.97>; colon surgery 0.85 < 0.49, 1.49>; and herniorrhaphy 1.48 < 0.67; 3.25>. CONCLUSIONS: Unexpectedly, in this analysis, which controlled for many patient and hospital-based confounders, OR ventilation with laminar airflow showed no benefit and was even associated with a significantly higher risk for severe SSI after hip prosthesis.

Modified guidelines impact on antibiotic use and costs: duration of treatment for pneumonia in a neurosurgical ICU is reduced.

OBJECTIVES: To evaluate the impact of an intervention to reduce the duration of antibiotic treatment for pneumonia in a neurosurgical intensive care unit (ICU). The usage of antibiotics and the resultant costs were examined using interrupted time series analysis while resistance and device-associated infection rates are also described. METHODS: In January 2004, revised guidelines for the use of antibiotics were implemented. As a consequence of this, the duration of antibiotic therapy for nosocomial pneumonia was reduced from 14 to 7 days, while for community-acquired pneumonia the period fell from 10 to 5 days. The effect on the antibiotic use density [AD; expressed as defined daily doses (DDD) per 1000 patient days (pd)] was calculated by segmented regression analysis of interrupted time series for the 24 months prior to (2002 and 2003) and after the intervention (2004 and 2005). RESULTS: The intervention was associated with a significant decrease in total AD from 949.8 to 626.7 DDD/1000 pd after the intervention. This was mainly due to reduced consumption of second-generation cephalosporins (-100.6 DDD/1000 pd), imidazoles (- 100.3 DDD/1000 pd), carbapenems (-33.3 DDD/1000 pd), penicillins with beta-lactamase inhibitor (-33.5 DDD/1000 pd) and glycopeptides (-30.2 DDD/1000 pd). Glycopeptide reduction might be associated with a significant decrease in the proportion of methicillin-resistant Staphylococcus aureus (8.4% before and 2.9% after the intervention). Similarly, total antibiotic costs/pd (Euro) showed a significant decrease from 13.16 Euro/pd before to 7.31 euro/pd after the intervention. This is a saving of 5.85 Euro/pd. The incidence of patients dying with pneumonia did not change significantly. CONCLUSIONS: The most conservative estimate of segmented regression analysis over a 48 month period showed that halving the duration of treatment for pneumonia results in a reduction of over 30% in antibiotic consumption and costs. Because respiratory infections are most common in ICU patients, interventions targeting a reduction in the duration of treatment of pneumonia might be extremely worthwhile.

Extract of Pelargonium sidoides (EPs 7630) improves phagocytosis, oxidative burst, and intracellular killing of human peripheral blood phagocytes in vitro.

Clinical data show that EPs 7630, an aqueous ethanolic extract from the roots of Pelargonium sidoides, can be used for the treatment of upper respiratory tract infections (URTI). The biological effects of the preparation have not been fully investigated. The objective of this study was to examine the impact of EPs 7630 on the activity of human peripheral blood phagocytes (PBP). A whole blood-based, flow cytometric assay was used to simultaneously assess phagocytosis and oxidative burst. Calcein-AM stained Candida albicans (DSM 1386) were used as target organisms. Oxidative burst was measured by addition of dihydroethidium (DHE). Target organisms and whole blood were co-incubated and analyzed after 0, 2, 4, 6, 10, and 30 min. Intracellular killing of the target organisms was evaluated by determining the number of surviving yeast cells after co-incubation of C. albicans and human whole blood. EPs 7630 was applied in therapeutically relevant concentrations between 0 and 30 microg/ml. Compared with controls EPs 7630 increased the number of phagocytosing PBP during the observed time points between 2 and 10 min in a concentration-dependent manner, with a maximum enhancement of 56% at 2 min (p=0.002). The application of EPs 7630 also led to a significant increase in the number of burst-active PBP for all time points observed beyond 2 min (p<0.001). The maximum augmentation was 120% after application of 30 microg/ml EPs 7630 at 4 min. Using a microbiological assay, intracellular killing was also enhanced by EPs 7630. This was expressed by a significant reduction in the number of surviving target organisms (p<0.001). The maximum reduction in viable yeast cells (-31%) was observed after co-incubation for 120 min with the highest concentration of EPs 7630 (30 microg/ml). In conclusion, the positive effects of EPs 7630 on phagocytosis, oxidative burst, and intracellular killing of yeast cells as test organisms are important components of the compound's biological activity. Our findings constitute a valuable contribution to understanding the clinical effects of EPs 7630.

Extract of Pelargonium sidoides (EPs 7630) inhibits the interactions of group A-streptococci and host epithelia in vitro.

EPs 7630 is an extract of the root of the South African geranium Pelargonium sidoides. Clinical data have shown that this herbal drug preparation can be used to treat upper respiratory tract infections (URTI). The objective of this study was to investigate the impact of EPs 7630 on group A-streptococci (GAS) adhering to and invading host epithelial cells in vitro. Adhesion was assessed by a flow cytometric adhesion assay using calcein-AM-stained S. pyogenes (DSM 2071) as test organism, and HEp-2 cells and buccal epithelial cells (BEC) as substrata. For cell invasion, HEp-2 cell monolayers were infected with S. pyogenes. Intracellular bacteria were determined using a penicillin/gentamicin-protection assay. EPs 7630 was applied in therapeutically relevant concentrations between 0 and 30 microg/ml in both test systems. Compared to controls, EPs 7630 significantly reduced GAS adhesion to HEp-2 cells in a concentration-dependent manner by up to 46% (p<0.001). This was semi-quantitatively confirmed by fluorescence microscopy. Adhesion kinetics additionally indicated a specific antagonistic effect on GAS adhesion. Pre-treatment of epithelial cells or GAS with EPs 7630 showed that it targets GAS rather than HEp-2 cells. However when using BEC as substrata, GAS adhesion increased 7-fold under the influence of EPs 7630 (p<0.001). In viability assays, HEp-2 suspension contained over 90% vital cells, whereas only 10% of the BEC were viable. EPs 7630 reduced GAS invasion of HEp-2 cells significantly when the data taken at time points 60, 120, and 180 min (p=0.026) were analyzed. In conclusion, EPs 7630 develops complementary anti-infective properties: Firstly, EPs 7630 reduces bacterial adhesion to intact epithelial cells and thus protects the organism from bacterial colonization and infection/super-infection. Secondly, EPs 7630 enhances the attachment of bacteria to decaying BEC. In this way pathogens may be trapped and rendered inactive. Thirdly, the inhibition of GAS invasion of epithelial cells protects the host from microorganisms that may have evaded host defences and antibiotic treatment, and therefore prevents recurrent infections. Thus, our investigations provide a rational basis for the treatment of URTI with EPs 7630.

Methicillin-resistant Staphylococcus aureus in German intensive care units during 2000-2003: data from Project SARI (Surveillance of Antimicrobial Use and Antimicrobial Resistance in Intensive Care Units).

OBJECTIVES: The objective of this study was to analyze methicillin-resistant Staphylococcus aureus (MRSA) percentages (defined as the percentage of S. aureus isolates that are resistant to methicillin) and antimicrobial consumption in intensive care units (ICUs) participating in Project SARI (Surveillance of Antimicrobial Use and Antimicrobial Resistance in Intensive Care Units), to look for temporal changes in MRSA percentages and antimicrobial consumption in individual ICUs as an indicator of the impact of an active surveillance system, and to investigate the differences between ICUs with increased MRSA percentages versus those with decreased percentages during a period of 3 years (2001-2003). METHODS: This was a prospective, ICU-based and laboratory-based surveillance study involving 38 German ICUs during 2000-2003. Antimicrobial use was reported in terms of defined daily doses (DDDs) per 1,000 patient-days. Temporal changes in the MRSA percentage and antimicrobial use in individual ICUs were calculated by means of the Wilcoxon signed rank test. The incidence density of nosocomial MRSA infection was defined as the number of nosocomial MRSA infections per 1,000 patient-days. RESULTS: From February 2000 through December 2003, a total of 38 ICUs reported data on 499,694 patient-days and 9,552 S. aureus isolates, including 2,249 MRSA isolates and 660,029 DDDs of antimicrobials. Cumulative MRSA percentages ranged from 0% to 64.4%, with a mean of 23.6%. The MRSA incidence density ranged from 0 to 38.2 isolates per 1,000 patient-days, with a mean of 2.77 isolates per 1,000 patient-days. There was a positive correlation between MRSA percentage and imipenem and ciprofloxacin use (P<.05). Overall, comparison of data from 2001 with data from 2003 showed that MRSA percentages increased in 18 ICUs (median increase, 13.2% [range, 1.6%-38.4%]) and decreased in 14 ICUs (median decrease, 12% [range, 1.0%-48.4%]). Increased use of third-generation cephalosporins, glycopeptides, or aminoglycosides correlated significantly with an increase in the MRSA percentage (P<.05). The cumulative nosocomial MRSA infection incidence density for 141 ICUs that did not participate in SARI and, therefore, did not receive feedback increased from 0.26 to 0.35 infections per 1,000 patient-days during a 3-year period, whereas the rate in SARI ICUs decreased from 0.63 to 0.40 infections per 1,000 patient-days. CONCLUSION: The MRSA situation in German ICUs is still heterogeneous. Because MRSA percentages range from 0% to 64.4%, further studies are required to confirm findings that no change in the MRSA percentage and a decrease in the nosocomial MRSA infection incidence density in SARI ICUs reflect the impact of an active surveillance system.

AMBU-KISS: quality control in ambulatory surgery.

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

Plasmid-mediated quinolone resistance in isolates obtained in german intensive care units.

Screening of 703 isolates of Enterobacteriaceae, obtained from 34 German intensive care units (ICUs), revealed qnr-positive, integron-containing isolates of Enterobacter sp. and Citrobacter freundii from four patients in 2 German ICUs. This is one of the first reports of qnr-positive strains obtained from patients in Europe.

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

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

Comparative in vitro activities of three new quinolones and azithromycin against aerobic pathogens causing respiratory tract and abdominal wound infections.

BACKGROUND: In our study the in vitro susceptibility of common pathogens that cause respiratory tract and abdominal wound infections was tested against two newer fluorquinolones (moxifloxacin and gatifloxacin) as well as levofloxacin and azithromycin. METHODS: 50 isolates each of methicillin-susceptible Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, Streptococcus pneumoniae, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa and Haemophilus influenzae isolated from the respiratory tract and from wounds were tested for their susceptibility to moxifloxacin, gatifloxacin, levofloxacin and azithromycin. RESULTS: Moxifloxacin proved to be the most active substance against the tested gram-positive pathogens. Gatifloxacin was the most active against P. aeruginosa. Moxifloxacin and gatifloxacin proved to be comparably active against the clinical isolates of E. coli and H. influenzae. CONCLUSIONS: Moxifloxacin and gatifloxacin display excellent activity against respiratory pathogens as well as nosocomial pathogens causing abdominal wound infections. When treating infections caused by P. aeruginosa the earlier fluorquinolones such as ciprofloxacin or ofloxacin are the substances of choice.

Does disinfection of environmental surfaces influence nosocomial infection rates? A systematic review.

OBJECTIVE: To review the evidence on the effects of disinfection of environmental surfaces in hospitals (as compared with cleaning without use of disinfectants) on the occurrence of nosocomial infections. METHODS: Systematic review of experimental and nonexperimental intervention studies dealing with environmental disinfection or cleaning in different health care settings. RESULTS: A total of 236 scientific articles were identified. None described a meta-analysis, systematic review, or randomized controlled trial. Only 4 articles described completed cohort studies matching the inclusion criteria. None of these studies showed lower infection rates associated with routine disinfection of surfaces (mainly floors) versus cleaning with detergent only. CONCLUSIONS: Disinfectants may pose a danger to staff, patients, and the environment and require special safety precautions. However, targeted disinfection of certain environmental surfaces is in certain instances an established component of hospital infection control. Given the complex, multifactorial nature of nosocomial infections, well-designed studies that systematically investigate the role of surface disinfection are required.

Pathogen growth in herbal teas used in clinical settings: a possible source of nosocomial infection?

In some clinical settings, herbal tea is used in patient care (eg, for oral hygiene). Teabags containing herbal tea were therefore tested with regard to the presence of microbial contamination before and after brewing. In addition, pathogen growth in intentionally contaminated brewed tea was investigated over time. Teabags and brewed tea were highly contaminated (maximum mean values of 1.9 x 10(8) CFU/g raw tea), and it was found that the pathogen load of intentionally contaminated tea increased significantly (by a maximum of 10(5) colony-forming units/mL brewed tea) over time, suggesting a possible risk of patients developing a nosocomial infection when used in patient care.

Surveillance of antimicrobial use and antimicrobial resistance in intensive care units (SARI): 1. Antimicrobial use in German intensive care units.

OBJECTIVE: To study antimicrobial use for benchmarking and ensuring quality of antimicrobial treatment and to identify risk factors associated with the high use of antimicrobials in German intensive care units (ICUs) through implementation of the SARI (Surveillance of Antimicrobial Use and Antimicrobial Resistance in ICUs) system. DESIGN: Prospective, unit-based surveillance on antimicrobial use from February, 2000, until June, 2002. The data are standardised by use of the defined daily dose (DDD) for each antimicrobial defined by the WHO and by calculating use per 1000 patient days. SETTING: The data were obtained from 35 German ICUs and stratified by type of ICU (medical, surgical, interdisciplinary). RESULTS: To date, the project covers a total of 266,013 patient days in 744 reported ICU months and 354,356 DDDs. Mean antimicrobial use density (AD) was 1,332 DDD/1000 patient days and was correlated with length of stay. Penicillins with beta-lactamase inhibitor (AD 338.3) and quinolones (155.5) were the antimicrobial group with the highest ADs. Comparison with US ICARE (Intensive Care Antimicrobial Resistance Epidemiology)/AUR (Antimicrobial Use and Resistance) data revealed a higher AD for glycopeptides and 3rd generation cephalosporins in ICARE/AUR ICUs, but a higher AD for carbapenems in German SARI ICUs regardless of the type of ICU. In the multivariate analysis, length of stay was an independent risk factor for an AD above the 75% percentile of the total amount of antimicrobials used (OR 1.96 per day); likewise, for the AD above the 75% percentile of carbapenems (OR 1.90 per day) and penicillins with extended spectrum (OR 2.01 per day). High use of glycopeptides and quinolones (AD >75% percentile) correlated with central venous catheter (CVC) rate (OR 1.14 per CVC day per 100 patient days and 1.16, respectively). CONCLUSION: The SARI data on antimicrobials serve ICUs as a benchmark by which to improve the quality of antimicrobial drug administration and for international comparison.

Discrimination of Klebsiella pneumoniae and Klebsiella oxytoca phylogenetic groups and other Klebsiella species by use of amplified fragment length polymorphism.

Bacteria of the genus Klebsiella are opportunistic pathogens responsible for an increasing number of multiresistant infections in hospitals. The two clinically and epidemiologically most important species, Klebsiella pneumoniae and K. oxytoca, have recently been shown to be subdivided into three and two phylogenetic groups, respectively. The aim of this study was an in depth evaluation of the amplified fragment length polymorphism (AFLP) genetic characterization method for epidemiological and phylogenic analyzes of Klebsiella isolates. First, we investigated the variability of AFLP patterns for Klebsiella strains within and between different outbreaks. Second, by use of carefully characterized phylogenetically representative strains, we examined whether different Klebsiella species and phylogenetic groups can be discriminated using AFLP. Twenty-four strains originating from seven presumed outbreaks and 31 non-associated strains were investigated. The AFLP fingerprints of all epidemiologically associated strains showed three or fewer fragment differences, whereas unrelated strains differed by at least four fragments. Cluster analysis of the AFLP data revealed a very high concordance with the phylogenetic assignation of strains based on the gyrA sequence and ribotyping data. The species K. pneumoniae, K. oxytoca, K. terrigena and the possibly synonymous pair K. planticola/K. ornithinolytica each formed a separate cluster. Similarly, strains of the phylogenetic groups of K. pneumoniae and K. oxytoca fell into their corresponding clusters, with only two exceptions. This study provides a preliminary cut-off value for distinguishing epidemiologically non-related Klebsiella isolates based on AFLP data; it confirms the sharp delineation of the recently identified phylogenetic groups, and demonstrates that AFLP is suitable for identification of Klebsiella species and phylogenetic groups.

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

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

Fungal granuloma of the sphenoid sinus and clivus in a patient presenting with cranial nerve III paresis: case report rand review of the literature.

OBJECTIVE AND IMPORTANCE: Isolated fungal granulomas originating within the sphenoid sinus are extremely rare in immunocompetent patients. In their symptoms and morphological appearance, these lesions may be mistaken for pituitary tumors. We report such a case and review the literature. CLINICAL PRESENTATION: A 74-year-old man presented with a 3-week history of Cranial Nerve III paresis. The patient had a long-term history of snuff abuse. Computed tomography demonstrated a space-occupying lesion of the sellar and sphenoid sinus region with displacement of the cavernous sinus. INTERVENTION: The lesion was operated on via a transnasal-transsphenoidal approach. After the sphenoid sinus was opened, mucus extruded spontaneously, and a brownish, crumbly mass was found and removed. The lesion had completely eroded the sella and clivus. Histological analysis revealed numerous Aspergillus hyphae. Postoperatively, the IIIrd cranial nerve paresis resolved completely within a few days. No systemic fungal infection was found in extensive serological studies. There was no evidence of immunosuppression. CONCLUSION: Fungal granuloma must be included in the differential diagnosis of lesions in the sellar region, even in nonimmunosuppressed patients. Early diagnosis and transsphenoidal extirpation is crucial with this potentially life-threatening disease.

Flow cytometric measurements of neutrophil functions: the dependence on the stimulus to cell ratio.

Phagocytosis and antimicrobial killing of neutrophils has been quantitatively determined as a function of the stimulus (Candida albicans) to cell ratio R using two donor collectives containing a total of 115 blood samples. Analysis of the collectives in two different laboratories according to the same flow cytometric protocol for simultaneous measurement of neutrophil functions did not produce statistically significant differences. The number of phagocytosing leukocytes as well as that of killed fungi per leukocyte depends strongly on R. While each phagocytosing neutrophil kills one fungus at low values of R, each neutrophil kills on average 2.5 fungi for large R.