Quantitative Antibiotic Use in Hospitals: Comparison of Measurements, Literature Review, and Recommendations for a Standard of Reporting

Abstract : Background: : Reports on antibiotic use often lack complete definitions of the units of measurement, hampering the comparison of data between hospitals or hospital units. Patients and Methods: : To compare methods of measures of in-hospital antimicrobial use, we determined aggregate in-hospital consumption data at a tertiary care university hospital using variations of nominators and denominators. Means of defined daily doses (DDD) of individual antimicrobials per 100 bed-days and per 100 admissions at each hospital and intensive care unit (ICU) were calculated. Furthermore, a literature review was performed for benchmarking purposes. Results: : Antibiotic use in different hospital units ranged from 0.105 to 323.37 DDD/100 bed-days and from 4.23 to 6737.92 DDD/100 admissions, respectively. Including the day of discharge in the denominator ‘bed-days' underestimated antibiotic use in various hospital wards by up to 27.7 DDD/100 bed-days (26.0%). Equating ‘numbers of patients admitted to the hospital' and ‘numbers of admissions' on a hospital level resulted in a difference of 192.6 DDD/100 admissions (64%) because patients transferred between hospital units accounted for multiple admissions. Likewise, reporting antimicrobial (Anatomical Therapeutic Chemical [ATC] group ‘J') instead of antibiotic (ATC group ‘J01') use led to a difference of 16.5 DDD/100 bed-days (19.3%). The literature review revealed underreporting of complete definitions of antibiotic use measurements. Conclusions: : Data on in-hospital antimicrobial use vary widely not only due to different antibiotic policies at different institutions but also due to different methods of measures. Adherence to the standard of reporting the methods of measurement is warranted for benchmarking and promotion of rational antimicrobial us

Initial management of and outcome in patients with pneumococcal bacteremia: a retrospective study at a Swiss university hospital, 2003-2009

Purpose: The aim of this quality control study was to assess the time to initial diagnostic procedures and the time to the first dose of antibiotics in patients with pneumococcal bacteremia, and to investigate whether the timeliness of these interventions influenced outcome. Methods: We retrospectively studied patient characteristics, chronological sequence of diagnostic and therapeutic steps, and the course of disease of all patients with pneumococcal bacteremia at a Swiss university hospital between 2003 and 2009, and we analyzed associations between these factors and the length of hospital stay (LOS) and mortality. Results: A total of 102 episodes of pneumococcal bacteremia in 98 patients were analyzed, of whom 15.7% died during hospitalization. The median time (interquartile range [IQR]) to the first antibiotic dose was 4.0 (2.0-5.9)h, and the median times (IQR]) to blood cultures, chest radiograph, lumbar puncture, and brain computed tomography (CT) scan or magnetic resonance imaging (MRI) were 1.4 (0.5-3.3), 2.5 (1.2-4.2), 4.2 (2.7-7.2), and 2.3 (0.6-6.2)h, respectively. The time to diagnostic procedures and therapy were not associated with LOS or death. Risk factors for death in the univariable analysis were: Charlson comorbidity index [odds ratio [OR] (95% confidence interval) per unit increase, 1.3 (1.1-1.6)], neutropenia [OR 10.1 (2.0-51.0)], human immunodeficiency virus (HIV) infection [OR 3.9 (1.1-13.8)], chronic respiratory disease [OR 4.4 (1.2-16.0)], chronic liver disease [OR 3.2 (1.0-9.7)], smoking [OR 3.8 (1.1-13.5)], injection drug use [OR 9.7 (1.5-63.7)], and antibiotic therapy within 6months before admission [OR 4.0 (1.3-12.5)]. The multivariable analysis revealed age >60years (P=0.048) and alcoholism (P=0.009) as risks for prolonged LOS. Conclusions: The outcome of pneumococcal bacteremia may be more influenced by patient characteristics than by minor differences in the timeliness of initial diagnostic and therapeutic measures within the first several hours after hospital admissio

Zoonotic pathogens and antimicrobial resistance in ‘animal-friendly’ pig production systems in Switzerland

In a cross-sectional study, the impact of ‘animal-friendly’ housing systems on the prevalence of Salmonella species, Campylobacter species, and Yersinia enterocolitica in finishing pigs and pork was investigated. Furthermore, antimicrobial resistance patterns of isolated campylobacter strains were analysed. In faecal samples of two out of 88 fattening pig farms salmonellae were isolated. All 865 samples of pork were found to be negative. Campylobacter was isolated on 98.9 % of the farms but only from 0.2 % of the pork samples. Yersiniae were found in samples of 63.3 % of the farms and in 15.4 % of pork samples. For all three bacteria, there was no statistically significant difference in the prevalence between conventional and ‘animal-friendly’ housing systems. In ‘animal-friendly’ farms, antimicrobial resistance of campylobacter isolates to fluoroquinolones and streptomycin was significantly less frequent than in conventional farms. Furthermore, fewer isolates had resistance to three or more antimicrobials in ‘animal-friendly’ farms

Risks Factors for Infections with Extended-Spectrum Beta-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae at a Tertiary Care University Hospital in Switzerland

Abstract : Background: : There are considerable geographical differencesin the occurrence of extended-spectrum beta-lactamase(ESBL)-producing bacteria, both in the community and in thehospital setting. Our aim was to assess risk factors forbloodstream, urinary tract, and vascular catheter-associatedinfections with ESBL-producing Escherichia coli and Klebsiellapneumoniae at a tertiary care hospital in a low-prevalencecountry. Methods: : We performed a case-control study comparing 58patients with infections due to ESBL-producing E. coli orK. pneumoniae vs 116 controls with infections due to non-ESBL producing organisms at the University Hospital Zurich,Switzerland, between 1 July 2005 and 30 June 2007. Results: : Cases included 15 outpatients and 43 inpatients.Multivariable analyses found three risk factors for ESBL-producingisolates: begin of symptoms or recent antibioticpre-treatment in a foreign country (odds ratio [OR] 27.01,95% confidence interval [CI] 2.38-1,733.28], p = 0.042),antibiotic therapy within the year preceding the isolation ofthe ESBL-producing strain (OR 2.88, 95% CI 1.13-8.49,p = 0.025), and mechanical ventilation (OR 10.56, 95% CI1.06-579.10, p = 0.042). Conclusions: : The major risk factors for infections due toESBL-producing bacteria were travel in high-prevalencecountries, prior antibiotic use, and mechanical ventilationduring a stay in the intensive care unit. Community-acquiredinfections were documented in 17% of the patients.An early identification of risk factors is crucial to providingthe patients an optimal empiric antibiotic therapy and tokeep the use of carbapenems to a minimu

Base-calling for next-generation sequencing platforms

Next-generation sequencing platforms are dramatically reducing the cost of DNA sequencing. With these technologies, bases are inferred from light intensity signals, a process commonly referred to as base-calling. Thus, understanding and improving the quality of sequence data generated using these approaches are of high interest. Recently, a number of papers have characterized the biases associated with base-calling and proposed methodological improvements. In this review, we summarize recent development of base-calling approaches for the Illumina and Roche 454 sequencing platforms

Factors associated with rifampin resistance in staphylococcal periprosthetic joint infections (PJI): a matched case-control study

Purpose: Rifampin combination therapy plays an important role in the management of staphylococcal periprosthetic joint infection (PJI). However, the emergence of rifampin resistance is a feared complication. We retrospectively analysed predetermined potential risk factors in patients with rifampin-resistant staphylococcal PJI in a multicentre case-control study. Methods: Cases (n=48) were defined as PJI caused by rifampin-resistant staphylococci. Rifampin-susceptible controls (n=48) were matched for microorganism and type of prosthetic joint. Uni- and multivariable conditional logistic regression analyses were performed to estimate odds ratios (OR) with 95% confidence intervals (95% CI). Results: Forty-eight cases (31 men; median age 67years; age range 39-88years) with hip- (n=29), knee- (n=13), elbow- (n=4), shoulder- (n=1) or ankle-PJI (n=1) were enrolled in the study. Staphylococcus aureus and coagulase-negative staphylococci were isolated in ten and 38 episodes, respectively. Most of the cases (n=44, 92%) had a previous PJI, and 93 % (n=41) of these had been treated with rifampin. There was an independent association of emergence of rifampin resistance with male sex (OR 3.6, 95% CI 1.2-11),≥3 previous surgical revisions (OR 4.7, 95% CI 1.6-14.2), PJI treatment with high initial bacterial load (inadequate surgical debridement, <2weeks of intravenous treatment of the combination medication; OR 4.9, 95% CI 1.6-15) and inadequate rifampin therapy (OR 5.4, 95% CI 1.2-25). Conclusions: Based on our results, extensive surgical debridement and adequate antibiotic therapy are needed to prevent the emergence of rifampin resistanc

Quantitative antibiotic use in hospitals: Comparison of measurements, literature review, and recommendations for a standard of reporting

BACKGROUND: Reports on antibiotic use often lack complete definitions of the units of measurement, hampering the comparison of data between hospitals or hospital units. METHODS: To compare methods of measures of in-hospital antimicrobial use, we determined aggregate in-hospital consumption data at a tertiary care university hospital using variations of nominators and denominators. Means of defined daily doses (DDD) of individual antimicrobials per 100 bed-days and per 100 admissions at each hospital and intensive care unit (ICU) were calculated. Furthermore, a literature review was performed for benchmarking purposes. RESULTS: Antibiotic use in different hospital units ranged from 0.105 to 323.37 DDD/100 bed-days and from 4.23 to 6737.92 DDD/100 admissions, respectively. Including the day of discharge in the denominator 'bed-days' underestimated antibiotic use in various hospital wards by up to 27.7 DDD/100 bed-days (26.0%). Equating 'numbers of patients admitted to the hospital' and 'numbers of admissions' on a hospital level resulted in a difference of 192.6 DDD/100 admissions (64%) because patients transferred between hospital units accounted for multiple admissions. Likewise, reporting antimicrobial (Anatomical Therapeutic Chemical [ATC] group 'J') instead of antibiotic (ATC group 'J01') use led to a difference of 16.5 DDD/100 bed-days (19.3%). The literature review revealed underreporting of complete definitions of antibiotic use measurements. CONCLUSIONS: Data on in-hospital antimicrobial use vary widely not only due to different antibiotic policies at different institutions but also due to different methods of measures. Adherence to the standard of reporting the methods of measurement is warranted for benchmarking and promotion of rational antimicrobial use

Nuclear fission: The "onset of dissipation" from a microscopic point of view

Semi-analytical expressions are suggested for the temperature dependence of those combinations of transport coefficients which govern the fission process. This is based on experience with numerical calculations within the linear response approach and the locally harmonic approximation. A reduced version of the latter is seen to comply with Kramers' simplified picture of fission. It is argued that for variable inertia his formula has to be generalized, as already required by the need that for overdamped motion the inertia must not appear at all. This situation may already occur above T=2 MeV, where the rate is determined by the Smoluchowski equation. Consequently, comparison with experimental results do not give information on the effective damping rate, as often claimed, but on a special combination of local stiffnesses and the friction coefficient calculated at the barrier.Comment: 31 pages, LaTex, 9 postscript figures; final, more concise version, accepted for publication in PRC, with new arguments about the T-dependence of the inertia; e-mail: [email protected]