The impact of antimicrobial use on the emergence of antimicrobial-resistant bacteria in hospitals

Integration of antimicrobial stewardship intervention with rapid organism identification improve outcomes in adult patients with bloodstream infections

BACKGROUND

Integration of antimicrobial stewardship intervention (ASI) with rapid organism identification has the potential for early customization of antimicrobial therapy and improved clinical outcomes. We aimed to evaluate the impact of this combined approach on antimicrobial therapy-related outcomes in patients with bloodstream infections (BSIs).

MATERIALS AND METHODS

A pre-post quasi-experimental study was conducted to analyze the impact of ASI with organism identification via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) among patients with BSIs. Outcomes were compared to a historic pre-intervention group. The 30-day mortality was the primary endpoint. Secondary outcomes included time to first antibiotic modification, length of hospital stay.

RESULTS

A total of 1004 adult patients with BSIs were included in the final analysis, 519 patients classified into the intervention group and 485 patients in the preintervention group. The patients in the intervention group were younger (66 vs. 70 years, P = 0.02). The 30-day crude mortality (14.6% vs. 29.9%, P < 0.001) was lower, the time to organism identification (72.25 vs. 83.6 h, P < 0.001) and length of hospital stay (12 days vs. 14 days, P < 0.001) were shorter in the intervention group. Acceptance of an ASI was associated with a trend toward a reduced 30-day mortality on multivariable analysis (odds ratio 0.33; 95% CI: 0.24-0.47; P < 0.001).

CONCLUSION

The ASI combined with MALDI-TOF-MS approach decreased time to organism identification and time to appropriate antimicrobial therapy would achieve a better clinical outcome in the patients with BSIs.

Diagnostic Accuracy and Agreement between Four Phenotypic Carbapenemase Detection Tests among Enterobacterales

Introduction:

Carbapenem-resistant Enterobacterales (CREs) are becoming increasingly popular as a cause of hospital-acquired infections that are difficult to treat and are frequently reported as causes of outbreaks in various hospitals. Conventional culturing techniques take at least 2 days to report a case as carbapenem resistant, and it is therefore important to detect such resistance mechanisms as early as possible.

Methods:

This study aimed to compare the diagnostic performance of Carba NP, modified Hodge test (MHT), ethylenediaminetetraacetic acid (EDTA) disk synergy test (DST), and the modified carbapenem inactivation method (mCIM). This study was done at Microbiology Laboratory, Aga Khan University Hospital, Karachi. It was an observational study. Carba NP, MHT, EDTA DST, and the mCIM were performed on consecutive isolates of Enterobacterales. Sensitivity, specificity, and agreement between the four tests were calculated.

Results:

Of 207 Enterobacterales isolated, 127 were resistant to carbapenems. One hundred and fourteen of these were tested by a polymerase chain reaction, and the sensitivities of the Carba NP, MHT, EDTA DST, and the mCIM were found to be 94.34%, 75.47%, 79.25%, and 98.11%, respectively.

Conclusions:

Due to increased rates of carbapenem resistance, there is a need to employ mechanisms in hospitals that can identify such organisms as early as possible, both from clinical and epidemiological standpoints. The Carba NP test is a rapid, cost–effective, and reliable method and mCIM is more accurate but time consuming and both can be safely used for the screening of CREs.

2020 EACTS/ELSO/STS/AATS Expert Consensus on Post-cardiotomy Extracorporeal Life Support in Adult Patients

Post-cardiotomy extracorporeal life support (PC-ECLS) in adult patients has been used only rarely but recent data have shown a remarkable increase in its use, almost certainly due to improved technology, ease of management, growing familiarity with its capability and decreased costs. Trends in worldwide in-hospital survival, however, rather than improving, have shown a decline in some experiences, likely due to increased use in more complex, critically ill patients rather than to suboptimal management. Nevertheless, PC-ECLS is proving to be a valuable resource for temporary cardiocirculatory and respiratory support in patients who would otherwise most likely die. Because a comprehensive review of PC-ECLS might be of use for the practitioner, and possibly improve patient management in this setting, the authors have attempted to create a concise, comprehensive and relevant analysis of all aspects related to PC-ECLS, with a particular emphasis on indications, technique, management and avoidance of complications, appraisal of new approaches and ethics, education and training.

2020 EACTS/ELSO/STS/AATS expert consensus on post-cardiotomy extracorporeal life support in adult patients

Post-cardiotomy extracorporeal life support (PC-ECLS) in adult patients has been used only rarely but recent data have shown a remarkable increase in its use, almost certainly due to improved technology, ease of management, growing familiarity with its capability and decreased costs. Trends in worldwide in-hospital survival, however, rather than improving, have shown a decline in some experiences, likely due to increased use in more complex, critically ill patients rather than to suboptimal management. Nevertheless, PC-ECLS is proving to be a valuable resource for temporary cardiocirculatory and respiratory support in patients who would otherwise most likely die. Because a comprehensive review of PC-ECLS might be of use for the practitioner, and possibly improve patient management in this setting, the authors have attempted to create a concise, comprehensive and relevant analysis of all aspects related to PC-ECLS, with a particular emphasis on indications, technique, management, and avoidance of complications, appraisal of new approaches and ethics, education, and training.

2020 EACTS/ELSO/STS/AATS expert consensus on post-cardiotomy extracorporeal life support in adult patients

Post-cardiotomy extracorporeal life support (PC-ECLS) in adult patients has been used only rarely but recent data have shown a remarkable increase in its use, almost certainly due to improved technology, ease of management, growing familiarity with its capability and decreased costs. Trends in worldwide in-hospital survival, however, rather than improving, have shown a decline in some experiences, likely due to increased use in more complex, critically ill patients rather than to suboptimal management. Nevertheless, PC-ECLS is proving to be a valuable resource for temporary cardiocirculatory and respiratory support in patients who would otherwise most likely die. Because a comprehensive review of PC-ECLS might be of use for the practitioner, and possibly improve patient management in this setting, the authors have attempted to create a concise, comprehensive and relevant analysis of all aspects related to PC-ECLS, with a particular emphasis on indications, technique, management and avoidance of complications, appraisal of new approaches and ethics, education and training.

2020 EACTS/ELSO/STS/AATS Expert Consensus on Post-Cardiotomy Extracorporeal Life Support in Adult Patients

Post-cardiotomy extracorporeal life support (PC-ECLS) in adult patients has been used only rarely but recent data have shown a remarkable increase in its use, almost certainly due to improved technology, ease of management, growing familiarity with its capability and decreased costs. Trends in worldwide in-hospital survival, however, rather than improving, have shown a decline in some experiences, likely due to increased use in more complex, critically ill patients rather than to suboptimal management. Nevertheless, PC-ECLS is proving to be a valuable resource for temporary cardiocirculatory and respiratory support in patients who would otherwise most likely die. Because a comprehensive review of PC-ECLS might be of use for the practitioner, and possibly improve patient management in this setting, the authors have attempted to create a concise, comprehensive and relevant analysis of all aspects related to PC-ECLS, with a particular emphasis on indications, technique, management and avoidance of complications, appraisal of new approaches and ethics, education and training.

Evaluation of the impact of the Accelerate Pheno™ system on time to result for differing antimicrobial stewardship intervention models in patients with gram-negative bloodstream infections

Background

Initiating early effective antimicrobial therapy is the most important intervention demonstrated to decrease mortality in patients with gram-negative bacteremia with sepsis. Rapid MIC-based susceptibility results make it possible to optimize antimicrobial use through both escalation and de-escalation.

Method

We prospectively evaluated the performance of the Accelerate Pheno™ system (AXDX) for identification and susceptibility testing of gram-negative species and compared the time to result between AXDX and routine standard of care (SOC) using 82 patient samples and 18 challenge organisms with various confirmed resistance mechanisms. The potential impact of AXDX on time to antimicrobial optimization was investigated with various simulated antimicrobial stewardship (ASTEW) intervention models.

Results

The overall positive and negative percent agreement of AXDX for identification were 100 and 99.9%, respectively. Compared to VITEK® 2, the overall essential agreement was 96.1% and categorical agreement was 95.4%. No very major or major errors were detected. AXDX reduced the time to identification by an average of 11.8 h and time to susceptibility by an average of 36.7 h. In 27 patients evaluated for potential clinical impact of AXDX on antimicrobial optimization, 18 (67%) patients could potentially have had therapy optimized sooner with an average of 18.1 h reduction in time to optimal therapy.

Conclusion

Utilization of AXDX coupled with simulated ASTEW intervention notification substantially shortened the time to potential antimicrobial optimization in this cohort of patients with gram-negative bacteremia. This improvement in time occurred when ASTEW support was limited to an 8-h coverage model.

Antibiotic Prescribing in Response to Bacterial Isolates in the Intensive Care Unit

This study aimed to identify potential knowledge-performance gaps in antibiotic prescribing for bacterial isolates in the Intensive Care Unit (ICU) in order to guide the development of interventions such as antibiotic policies, decision support, and improved systems for communication between the laboratory and the bedside. A prospective observational cohort study of all patients admitted to a mixed medical/surgical ICU was undertaken over a six-month period in an Australian adult tertiary hospital. From a cohort of 524 patients, 108 had 303 isolates that were eligible for inclusion. Overall, 14.3% and 30.8% of sterile and non-sterile isolates respectively were associated with inadequate initial antibiotic therapy after identification of the bacteria. After sensitivity results were available inadequate directed therapy was observed in 4.0% and 21.3% of sterile and non-sterile isolates respectively. Problems were most commonly associated with isolates of Pseudomonas spp., Stenotrophomonas spp., Acinetobacter spp., S. aureus, enterococci and group III Enterobacteriaceae. Inadequate antibiotic therapy was found to be independently associated with prolonged length of ICU stay. Narrower spectrum antibiotic therapy was potentially available for 30% of isolates after sensitivity results were known. We conclude that there is scope to improve antibiotic prescribing in the ICU by providing clinicians with access to information regarding local susceptibility patterns and intrinsic resistance of bacteria, and spectra of antibiotic cover. Timely notification of laboratory results at the point of care may also facilitate improved prescribing performance.

Pseudomonas aeruginosa bacteremia among liver transplant recipients

Pseudomonas aeruginosa bacteremia remains as a life-threatening complication after liver transplantation (LT) and is intractable because of the high rate of drug resistance to commonly used antibiotics. To better understand the characteristics of this postoperative complication, PubMed and Embase searches as well as reference mining was done for relevant literature from the start of the databases through August 2018. Among LT recipients, the incidence of P. aeruginosa bacteremia ranged from 0.5% to 14.4% and mortality rates were up to 40%. Approximately 35% of all episodes of bloodstream infections (BSIs) were P. aeruginosa bacteremia, of which 47% were multidrug resistant and 63% were extensively drug resistant. Several factors are known to affect the mortality of LT recipients with P. aeruginosa bacteremia, including hypotension, mechanical ventilation, and increasing severity of illness. In LT recipients with P. aeruginosa bacteremia, alteration in DNA gyrase A genes and overexpression of proteins involved in efflux systems, namely the expression of KPC-2-type carbapenemase, NDM-1, and VIM-2-type MBL, contribute to the high resistance of P. aeruginosa to a wide variety of antibiotics. Because of complicated mechanisms of drug resistance, P. aeruginosa causes high morbidity and mortality in bacteremic LT patients. Consequently, early detection and treatment with adequate early targeted coverage for P. aeruginosa BSI are of paramount importance in the early posttransplantation period to obtain a better prognosis for LT patients.

Clinical Utility of Rapid Pathogen Identification for Detecting the Causative Organisms in Sepsis: A Single-Center Study in Korea

Purpose

The aim of this pre- and postintervention cohort study was evaluating how effectively rapid pathogen identification with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) detected the causative organisms in sepsis.

Methods

All consecutive adult patients who had bacteremia within 72 h of intensive care unit admission and met ≥2 quick Sequential Organ Failure Assessment criteria at intensive care unit admission were analyzed. The patients whose microorganisms were identified via MALDI-TOF MS between March 2014 and February 2016 formed the postintervention group. The patients whose microorganisms were identified by using conventional methods between March 2011 and February 2013 formed the preintervention group.

Results

The postintervention group (n=58) had a shorter mean time from blood draw to receiving the antimicrobial susceptibility results than the preintervention group (n=40) (90.2 ± 32.1 vs. 108.7 ± 43.1 h; p=0.02). The postintervention group was also more likely to have received active antimicrobial therapy by the time the susceptibility report became available (77% vs. 47%; p=0.005). Its 28-day mortality was also lower (40% vs. 70%; p=0.003). Univariate analysis showed that identification via MALDI-TOF MS (odds ratio, 0.28; 95% confidence interval, 0.12–0.66; p=0.004) and active therapy (odds ratio, 0.38; 95% confidence interval, 0.16–0.95; p=0.04) were associated with lower 28-day mortality.

Conclusion

Rapid microorganism identification via MALDI-TOF MS followed by appropriate antimicrobial therapy may improve the clinical outcomes of patients with sepsis.

Duration of antibiotic treatment after endoscopic ultrasound-guided drainage of walled-off pancreatic necrosis not affecting outcomes

BACKGROUND AND AIM

Although society guidelines recommend a short course of antibiotics after drainage of walled-off necrosis (WON), the exact duration is unclear.

METHODS

This is a retrospective review of patients with no prior antibiotic exposure who underwent dual-modality drainage (DMD) for sterile WON from 2008 to 2017. Patients were grouped into short duration (SD, ≤5 days) versus long duration (LD, >5 days). The main outcome was the frequency of recurrent infections.

RESULTS

Sixty-one patients (25 in the SD group and 36 in the LD group) were included. Patients in the two groups had comparable age, comorbidities, and severity of disease (P = 0.89). Patients in the SD group were treated with antibiotics for a median of 3 days compared with 8.5 days in the LD group. There were no differences in recurrent febrile episodes within 30 days of procedure-44% of SD group versus 39% of LD (P = 0.69). There was also no difference in time to resolution of WON (64 days for both groups, P = 0.72) or duration of hospitalization post-DMD (SD 7.7 days versus LD 7.5 days, P = 0.42). Three cases of Clostridium difficile colitis were observed in the LD group.

CONCLUSIONS

Longer course of antibiotics seems to have similar outcomes compared with shorter courses in patients with WON treated with DMD. Prolonged-course therapy may predispose to secondary infections like C. difficile colitis. A randomized controlled trial is needed to evaluate the role and duration of peri-procedural antibiotics after drainage of sterile WON.

Antibiotic-Stewardship Practices at Top Academic Centers Throughout the United States and at Hospitals Throughout Massachusetts

Objective.

Improvements in antibiotic prescribing to reduce bacterial resistance and control hospital costs is a growing priority, but the way to accomplish this is poorly defined. Our goal was to determine whether certain antibiotic stewardship interventions were universally instituted and accepted at top US academic centers and to document what interventions, if any, are used at both teaching and community hospitals within a geographic area.

Design.

Two surveys were conducted. In survey 1, detailed phone interviews were performed with the directors of antibiotic stewardship programs at 22 academic medical centers that are considered among the best for overall medical care in the United States or as leaders in antibiotic stewardship programs. In survey 2, teaching and community hospitals throughout Massachusetts were surveyed to ascertain what antibiotic oversight program components were present.

Results.

In survey 1, each of the 22 participating hospitals had instituted interventions to improve antibiotic prescribing, but none of the interventions were universally accepted as essential or effective. In survey 2, of 97 surveys that were mailed to prospective participants, a total of 54 surveys from 19 teaching hospitals and 35 community hospitals were returned. Ninety-five percent of the teaching hospitals had a restricted formulary, compared with 49% of the community hospitals, and 89% of teaching hospitals had an antibiotic approval process, compared with 29% of community hospitals.

Conclusion.

There was great variability among the approaches to the oversight of antibiotic prescribing at major academic hospitals. Antibiotic management interventions were lacking in more than half of the Massachusetts community hospitals surveyed. More research is needed to define the best antibiotic stewardship interventions for different hospital settings.

Effect of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) Alone versus MALDI-TOF MS Combined with Real-Time Antimicrobial Stewardship Interventions on Time to Optimal Antimicrobial Therapy in Patients with Positive Blood Cultures

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) decreases the time to organism identification and improves clinical and financial outcomes. The purpose of this study was to evaluate the impact of MALDI-TOF MS alone versus MALDI-TOF MS combined with real-time, pharmacist-driven, antimicrobial stewardship (AMS) intervention on patient outcomes. This single-center, pre-post, quasiexperimental study evaluated hospitalized patients with positive blood cultures identified via MALDI-TOF MS combined with prospective AMS intervention compared to a control cohort with MALDI-TOF MS identification without AMS intervention. AMS intervention included: real-time MALDI-TOF MS pharmacist notification and prospective AMS provider feedback. The primary outcome was the time to optimal therapy (TTOT). A total of 252 blood cultures, 126 in each group, were included in the final analysis. MALDI-TOF MS plus AMS intervention significantly reduced the overall TTOT (75.17 versus 43.06 h; P < 0.001), the Gram-positive contaminant TTOT (48.21 versus 11.75 h; P < 0.001), the Gram-negative infection (GNI) TTOT (71.83 versus 35.98 h; P < 0.001), and the overall hospital length of stay (LOS; 15.03 versus 9.02 days; P = 0.021). The TTOT for Gram-positive infection (GPI) was improved (64.04 versus 41.61 h; P = 0.082). For GPI, the hospital LOS (14.64 versus 10.31 days; P = 0.002) and length of antimicrobial therapy 24.30 versus 18.97 days; P = 0.018) were reduced. For GNI, the time to microbiologic clearance (51.13 versus 34.51 h; P < 0.001), the hospital LOS (15.40 versus 7.90 days; P = 0.027), and the intensive care unit LOS (5.55 versus 1.19 days; P = 0.035) were reduced. To achieve optimal outcomes, rapid identification with MALDI-TOF MS combined with real-time AMS intervention is more impactful than MALDI-TOF MS alone.

Unnecessary Antibiotics for Acute Respiratory Tract Infections: Association With Care Setting and Patient Demographics

Background.  Up to 40% of antibiotics are prescribed unnecessarily for acute respiratory tract infections (ARTIs). We sought to define factors associated with antibiotic overprescribing of ARTIs to inform efforts to improve practice. Methods.  We conducted a retrospective analysis of ARTI visits between 2006 and 2010 from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey. Those surveys provide a representative sample of US visits to community-based physicians and to hospital-based emergency departments (EDs) and outpatient practices. Patient factors (age, sex, race, underlying lung disease, tobacco use, insurance), physician specialty, practice demographics (percentage poverty, median household income, percentage with a Bachelor's Degree, urban-rural status, geographic region), and care setting (ED, hospital, or community-based practice) were evaluated as predictors of antibiotic overprescribing for ARTIs. Results.  Hospital and community-practice visits had more antibiotic overprescribing than ED visits (odds ratio [OR] = 1.64 and 95% confidence interval [CI], 1.27-2.12 and OR = 1.59 and 95% CI, 1.26-2.01, respectively). Care setting had significant interactions with geographic region and urban and rural location. The quartile with the lowest percentage of college-educated residents had significantly greater overprescribing (adjusted OR = 1.41; 95% CI, 1.07-1.86) than the highest quartile. Current tobacco users were overprescribed more often than nonsmokers (OR = 1.71; 95% CI, 1.38-2.12). Patient age, insurance, and provider specialty were other significant predictors. Conclusions.  Tobacco use and a lower grouped rate of college education were associated with overprescribing and may reflect poor health literacy. A focus on educating the patient may be an effective approach to stewardship.

Resource-saving advice from an infectious diseases specialist team in a large university hospital: an exportable model?

AIM

To assess epidemiological features of patients for which a consultation by the infectious diseases consultation team was required, and the rate of clinical advice that led to resource-saving advice (R-SA): discontinuation of inappropriate therapy or prophylaxis, de-escalation and switch from parenteral to oral therapy.

MATERIALS & METHODS

An infectious diseases consultation team was implemented in a 1100-bed university hospital in Italy.

RESULTS

The most frequent infections for which an infectious diseases consultancy was required were pneumonia, bloodstream infections (17% by Candida) and urinary tract infections. In 828 patients (41.4%), interventions with the possibility of R-SA were suggested.

CONCLUSION

Resource-saving advices were possible in 41% of cases. Recent surgery, having a central venous catheter, bloodstream, abdominal, surgical site or bone and joint infections were correlated to a higher probability of receiving R-SA.

Factors affecting caregivers' use of antibiotics available without a prescription in Peru

OBJECTIVE

To determine factors that affect caregivers' decisions about antibiotic use in children in settings where antibiotics are available without prescription.

METHODS

In a house-to-house survey, 1200 caregivers in 3 periurban districts of Lima, Peru, were asked about antibiotic use in young children.

RESULTS

In this sample, 87.2% of children aged <5 years had received an antibiotic drug in their lives; 70.3% had received antibiotics before 1 year of age, and 98.8% of those had been prescribed by a physician. Given hypothetical cases of common cold and nondysenteric diarrhea, caregivers would seek medical advice in 76.4% and 87.1%, respectively, and 84.6% of caregivers said they respected medical decisions even if an antibiotic was not prescribed. Caregivers with high school-level education accepted 80% more medical decisions of not using an antibiotic and used fewer pharmacist-recommended antibiotics. For each additional year of life, the risk of self-medicated antibiotic use and the use of pharmacist-recommended antibiotics increased in 30%. (OR: 1.3, 95% CI: 1.1-1.4, P = .001 and OR: 1.3, 95% CI: 1.2-1.5, P < .001, respectively). Caregivers respected a medical decision of not prescribing an antibiotic 5 times more when physicians had explained the reason for their advice (OR: 5.0, 95% CI: 3.2-7.8, P < .001).

CONCLUSIONS

Prescribed antibiotic use in these young children is common. Even if they are available without prescription, caregivers usually comply with medical advice and follow physicians' recommendations when antibiotics are not prescribed. Improving physician prescribing habits could reduce irrational antibiotic use, decreasing future caregiver-driven misuse.

Risk factors for carbapenem-resistant Gram-negative bacteremia in intensive care unit patients

PURPOSE

Carbapenem-resistant (CR) Gram-negative pathogens have increased substantially. This study was performed to identify the risk factors for development of CR Gram-negative bacteremia (GNB) in intensive care unit (ICU) patients.

METHODS

Prospective study; risk factors for development of CR-GNB were investigated using two groups of case patients: the first group consisted of patients who acquired carbapenem susceptible (CS) GNB and the second group included patients with CR-GNB. Both case groups were compared to a shared control group defined as patients without bacteremia, hospitalized in the ICU during the same period.

RESULTS

Eighty-five patients with CR- and 84 patients with CS-GNB were compared to 630 control patients, without bacteremia. Presence of VAP (OR 7.59, 95 % CI 4.54-12.69, p < 0.001) and additional intravascular devices (OR 3.69, 95 % CI 2.20-6.20, p < 0.001) were independently associated with CR-GNB. Presence of VAP (OR 2.93, 95 % CI 1.74-4.93, p < 0.001), presence of additional intravascular devices (OR 2.10, 95 % CI 1.23-3.60, p = 0.007) and SOFA score on ICU admission (OR 1.11, 95 % CI 1.03-1.20, p = 0.006) were independently associated with CS-GNB. The duration of exposure to carbapenems (OR 1.079, 95 % CI 1.022-1.139, p = 0.006) and colistin (OR 1.113, 95 % CI 1.046-1.184, p = 0.001) were independent risk factors for acquisition of CR-GNB. When the source of bacteremia was other than VAP, previous administration of carbapenems was the only factor related with the development of CR-GNB (OR 1.086, 95 % CI 1.003-1.177, p = 0.042).

CONCLUSIONS

Among ICU patients, VAP development and the presence of additional intravascular devices were the major risk factors for CR-GNB. In the absence of VAP, prior use of carbapenems was the only factor independently related to carbapenem resistance.

Nosocomial Gram-positive antimicrobial susceptibility pattern at a referral teaching hospital in Tehran, Iran

Aims: The aim of the study was to evaluate epidemiology and susceptibility patterns of nosocomial Gram-positive infections in a referral teaching hospital. Methods: Over a 1 year period, Gram-positive microorganisms isolated from specimens of hospitalized patients with documented nosocomial infection underwent antimicrobial susceptibility testing using the disk diffusion test. In addition, possible risk factors for developing multidrug-resistant bacteria were evaluated. Results: During the study period, a total of 137 nosocomial infections were detected. Staphylococcus aureus was the most frequently isolated microorganism (56.2%), followed by Enterococcus spp. (21.9%) and Staphylococcus epidermidis (15.3%). All S. aureus strains were sensitive to vancomycin, teicoplanin, linezolid and chloramphenicol. More than 50% of enterococci strains were resistant to vancomycin and teicoplanin. Possible risk factors for multidrug resistance among isolated pathogens were history of antibiotic use and intubation of patient for mechanical ventilation. Conclusion: This study showed high rates of antimicrobial resistance among nosocomial Gram-positive pathogens, complicating antibiotic therapy and its outcomes.

Original submitted 26 March 2012; Revised submitted 27 April 2012

Antibiotic contamination and occurrence of antibiotic-resistant bacteria in aquatic environments of northern Vietnam

The ubiquitous application and release of antibiotics to the environment can result in bacterial antibiotic resistance, which in turn can be a serious risk to humans and other animals. Southeast Asian countries commonly apply an integrated recycling farm system called VAC (Vegetable, Aquaculture and Caged animal). In the VAC environment, antibiotics are released from animal and human origins, which would cause antibiotic-resistant bacteria (ARB). This study evaluated occurrence of ARB in the VAC environment in northern Vietnam, with quantitative analysis of antibiotic pollution. We found that sulfonamides were commonly detected at all sites. In dry season, while sulfamethazine was a major contaminant in pig farm pond (475-6662 ng/l) and less common in city canal and aquaculture sites, sulfamethoxazole was a major one in city canal (612-4330 ng/l). Erythromycin (154-2246 ng/l) and clarithromycin (2.8-778 ng/ml) were the common macrolides in city canal, but very low concentrations in pig farm pond and aquaculture sites. High frequencies of sulfamethoxazole-resistant bacteria (2.14-94.44%) were found whereas the occurrence rates of erythromycin-resistant bacteria were lower (<0.01-38.8%). A positive correlation was found between sulfamethoxazole concentration and occurrence of sulfamethoxazole-resistant bacteria in dry season. The sulfamethoxazole-resistant isolates were found to belong to 25 genera. Acinetobacter and Aeromonas were the major genera. Twenty three of 25 genera contained sul genes. This study showed specific contamination patterns in city and VAC environments and concluded that ARB occurred not only within contaminated sites but also those less contaminated. Various species can obtain resistance in VAC environment, which would be reservoir of drug resistance genes. Occurrence of ARB is suggested to relate with rainfall condition and horizontal gene transfer in diverse microbial community.

Managing antimicrobial resistance in intensive care units

The challenges in managing patients with infection in the intensive care unit are increased in an era where there are dwindling antimicrobial choices for multidrug-resistant pathogens. Clinicians in the intensive care unit must balance between choosing appropriate antimicrobial treatment for patients with suspected infection and utilizing antimicrobials in a judicious fashion. Improving antimicrobial utilization is a critical component to reducing antimicrobial resistance. Although providing effective antimicrobial therapy and improving antimicrobial utilization may seem to be competing goals, there are effective strategies to accomplish both. Antimicrobial stewardship programs provide an organized way to implement these strategies and can enhance the intensive care unit physician's success in improving patient outcomes and combating antimicrobial resistance in the intensive care unit.

The evolution of drug-resistant microorganisms in patients with prolonged mechanical ventilation

BACKGROUND

Patients requiring prolonged mechanical ventilation (PMV) tend to become reservoirs of antimicrobial resistance. We assessed antimicrobial-resistant microorganisms in the respiratory tracts of patients receiving PMV.

METHODS

Over a 6-month period, the microorganisms from tracheal aspirates of PMV patients with lower airway infection were analyzed.

RESULTS

Antimicrobial use was greatest during the acute critical stage of respiratory failure. Antimicrobial resistance in Pseudomonas aeruginosa and Klebsiella pneumoniae peaked during the fourth to 15th weeks of PMV. Methicillin-resistant Staphylococcus aureus (MRSA) developed rapidly during the first 3 weeks of PMV. The acquisition of multidrug-resistant P aeruginosa and MRSA were significantly correlated with previous exposure to ceftazidime (odds ratio [OR] = 121.3 and 72.5; P = .01 and .01, respectively). The rise of multidrug-resistant Acinetobacter baumannii was significantly correlated with previous exposure to piperacillin/tazobactam (OR = 26.81; P = .02) and imipenem (OR = 16.91; P = .03). Using univariate and multivariate logistic regression models, the lower respiratory tract infections with multidrug-resistant microorganisms were independently associated with increased 6-month mortality (OR = 3.41; P < .01).

CONCLUSION

In patients receiving PMV, lower respiratory tract infection with multidrug-resistant microorganisms is common and is associated with higher mortality.

Effect of utilization policies for fluoroquinolones: a pilot study in nova scotia hospitals

BACKGROUND

Antimicrobial resistance results in increased morbidity, mortality, and costs to the health care system. Evidence suggests an association between the use of antimicrobials in hospitals and the development of antimicrobial resistance. Fluoroquinolones constitute one group of antimicrobials that are effective against a variety of bacterial infections, yet they may be subject to misuse. Many hospitals in Nova Scotia have implemented policies to improve antimicrobial prescribing, but the impact of these policies on utilization is unknown.

OBJECTIVES

To evaluate the use of fluoroquinolones in Nova Scotia hospitals using the World Health Organization's Anatomical Therapeutic Chemical classification system with defined daily doses (ATC/DDD) and to examine the influence of hospital policies for utilization of fluoroquinolones in community-acquired pneumonia.

METHODS

During the study period (April 1, 1997, to March 31, 2003), fluoroquinolones were administered at 31 of the 37 hospitals in Nova Scotia's 9 district health authorities. Hospital administrative data, hospital characteristics, and pharmaceutical purchasing data related to use of these drugs were aggregated using the ATC/DDD methodology for the fiscal years 1997/1998 to 2002/2003. District pharmacy directors were surveyed to obtain information about district and individual hospital antibiotic policies. Descriptive statistics were calculated, and univariable regression and multilevel analyses were performed.

RESULTS

Mean overall fluoroquinolone use increased over the study period, from 47.2 DDD/1000 bed-days per year in fiscal year 1997/1998 to 163.8 DDD/1000 bed-days per year in fiscal year 2002/2003 (p < 0.001). Multilevel analysis showed that utilization policies aimed at appropriate prescribing did not affect the use of fluoroquinolones.

CONCLUSION

This study revealed that drug purchasing, hospital administrative, and diagnostic data could be combined to compare the utilization of fluoroquinolones among different hospitals and district health authorities. Utilization policies had little effect on the amount, type, or route of fluoroquinolone use.

Pseudomonas aeruginosa infection after living-donor liver transplantation in adults

OBJECTIVES

Pseudomonas aeruginosa infection is a major cause of bacterial infection after deceased-donor liver transplantation. The incidence and risk factors of P. aeruginosa infection after living-donor liver transplantation (LDLT), however, are not known.

METHODS

We retrospectively reviewed the data from 170 adult patients who underwent LDLT at the University of Tokyo Hospital. The microbiologic and medical records of the patients from admission to 3 months after LDLT were reviewed. Uni- and multivariate analyses were performed to identify the independent risk factors for postoperative P. aeruginosa infection.

RESULT

Preoperative P. aeruginosa carriage was identified in 15 (9%) patients. Only 2 of the 15 patients later presented with postoperative P. aeruginosa infection. Postoperative P. aeruginosa infection occurred in 27 (16%) of 170 patients by median postoperative day 38. Among those 27 patients, surgical site infections were recorded in 8 (30%) and intra-abdominal infections in 14 (52%). In 5 of the 27 (19%) patients, P. aeruginosa isolates were multiple antimicrobial resistant. Postoperative bile leakage independently predicted postoperative P. aeruginosa infection.

CONCLUSION

P. aeruginosa infections were frequently detected after LDLT, including those by multiple antimicrobial-resistant isolates. Postoperative bile leakage predisposed patients to P. aeruginosa infection. Surveillance culture should be checked periodically after LDLT to ensure that appropriate antimicrobials can be administered for postoperative infection.

Antibiotic use in two cohorts of German intensive care units

Antibiotic use was evaluated in two cohorts of intensive care units (ICUs) in Germany. One cohort included ICUs participating in a surveillance programme (N=34) collecting antibiotic use and bacterial resistance data, with quarterly feedback. The second ICU cohort was from a cross-sectional study and represented a sample from hospitals in South-west Germany (N=58). Two dose definitions were used. These were the World Health Organization/Anatomical Therapeutic Chemical Classification (ATC) 2001 definition of defined daily dose (DDD), and a definition of recommended daily dose (RDD) that better reflected the currently prescribed dosages of parenteral drugs for hospitalized patients. Data were expressed as DDD or RDD per 100 patient-days. It was determined whether hospital size and affiliation, year of study and ICU type had an influence on overall use of antibiotics. Overall use differed between the two ICU cohorts irrespective of the dose definitions used. High use of antibiotics was primarily associated with hospital affiliation (university vs non-university) and hospital size. Mean overall use of antibiotics in non-university hospital ICUs ranged between 106 and 111 DDD/100 (59 and 67 RDD/100) for different hospital size categories, compared with 140 DDD/100 (87 RDD/100) in university hospital ICUs. In conclusion, in order to compare the use of antibiotics between ICU cohorts and to assess trends over time, data adjustment is required for hospital affiliation and size.

Antimicrobial susceptibility and molecular analysis of Enterococcus faecalis originating from endodontic infections in Finland and Lithuania

BACKGROUND/AIMS

Enterococcus faecalis strains with multiple antibiotic resistances can cause infections that are difficult to treat. The microbial flora in treatment-resistant apical periodontitis is dominated by E. faecalis, and is a potential source of infections at other sites.

MATERIAL AND METHODS

Sensitivities to a range of antibiotics were determined for 59 endodontic E. faecalis isolates from Finland and Lithuania. The DNA sequence of the gene responsible for the species' intrinsic quinupristin-dalfopristin resistance, lsa, was determined from two isolates with diminished resistance. Four pairs of isolates from the same root canal were typed by pulsed-field gel electrophoresis.

RESULTS

A high prevalence of resistance to rifampicin was found, whereas all isolates were susceptible or showed intermediate susceptibility to penicillin and ampicillin and four isolates were unusually susceptible to cefotaxime. No vancomycin or high-level gentamicin resistance was detected. Nine of 59 isolates were susceptible to quinupristin-dalfopristin. A fully quinupristin-dalfopristin-susceptible isolate also susceptible to clindamycin produced a truncated Lsa polypeptide, and an isolate with borderline quinupristin-dalfopristin-susceptibility had mutations proximal to the predicted ribosomal binding site. Pulsed-field gel electrophoresis showed that the same root canal could harbor two different strains of E. faecalis during the course of the same infection.

CONCLUSION

Despite the differing antibiotic usage in Finland and Lithuania, E. faecalis from endodontic infections in these countries showed similar susceptibility patterns with levels of resistance considered typical for the species, and decreased resistance to clindamycin and quinupristin-dalfopristin as well as lesions in the lsa gene which were similar to those described in other clinical isolates.

Relationships between antimicrobial use and antimicrobial resistance in Gram-negative bacteria causing nosocomial infections from 1991-2003 at a university hospital in Taiwan

This study was conducted to evaluate the relationship between antimicrobial resistance and antimicrobial use in a university hospital in Taiwan. Disk susceptibility data of Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens, Proteus spp., Pseudomonas aeruginosa, Acinetobacter spp., Stenotrophomonas maltophilia and other non-fermentative Gram-negative bacilli causing nosocomial infections were evaluated. Data on annual patient-days and annual consumption (defined daily dose (DDD) per 1000 patient-days) of extended-spectrum cephalosporins (cefotaxime, ceftriaxone, ceftazidime, flumoxef, cefepime and cefpirome), β-lactam–β-lactamase inhibitor combinations (ticarcillin/clavulanic acid and piperacillin/tazobactam), carbapenems (imipenem and meropenem), aminoglycosides (amikacin, gentamicin and tobramycin), fluoroquinolones (ciprofloxacin (oral and injectable) and oral levofloxacin and moxifloxacin) from 1991 to 2003 were analysed. Increasing trends of incidences of several of these bacteria causing all nosocomial infections or nosocomial bloodstream infections were noted from 1991 to 2003. The annual patient-days of the hospital significantly increased, from 360 210 in 1991 to 672 676 in 2002 (linear regression analysis, P < 0.05), but slightly decreased in 2003 (629 168) owing to the severe acute respiratory syndrome epidemic in Taiwan. The rise in cefotaxime-resistant or ciprofloxacin-resistant E. coli and meropenem-resistant P. aeruginosa was significantly correlated with increased consumption of extended-spectrum cephalosporins, β-lactam–β-lactamase inhibitor combinations, carbapenems, fluoroquinolones and aminoglycosides (for ciprofloxacin-resistant E. coli and meropenem-resistant P. aeruginosa only) in the hospital (Pearson's correlation coefficient, r > 0.72 (or <−0.72) and P-value < 0.05). Increased ciprofloxacin-resistant K. pneumoniae and meropenem-resistant Acinetobacter spp. was significantly associated with the increased usage of extended-spectrum cephalosporins but not with the other four classes of antibiotics. This 13-year study in a hospital demonstrated significant changes in antimicrobial use, which may have affected antimicrobial resistance in certain Gram-negative bacteria at the hospital.

A pilot study of antibiotic cycling in the community hospital setting

OBJECTIVE

To assess the feasibility of a quarterly antibiotic cycling program at two community hospitals and to evaluate its safety and impact on antibiotic use, expenditures, and resistance.

DESIGN

Nonrandomized, longitudinal cohort study.

SETTING

Two community hospitals, one teaching and one non-teaching.

PATIENTS

Adult medical and surgical inpatients requiring empiric antibiotic therapy.

INTERVENTION

We developed and implemented a treatment protocol for the empiric therapy of common infections. Between July 2000 and June 2002, antibiotics were cycled quarterly; quinolones, beta-lactam-inhibitor combinations, and cephalosporins were used. Protocol adherence, adverse drug events, nosocomial infections, antibiotic use and expenditures, resistance among clinical isolates, and length of stay were assessed during eight quarters.

RESULTS

Physicians adhered to the protocol for more than 96% of 2,494 eligible patients. No increases in nosocomial infections or adverse drug events were attributed to the cycling protocol. Antibiotic acquisition costs increased 31%; there was a 14.7% increase in antibiotic use. Length of stay declined by 1 day. Quarterly variability in the prevalence of vancomycin-resistant enterococci and ceftazidime resistance among combined gram-negative organisms were noted.

CONCLUSIONS

Implementation of an antibiotic cycling program is feasible in a community hospital setting. No adverse safety concerns were identified. Antibiotic cycling was more expensive, partly due to an increase in antibiotic use to optimize initial empiric therapy. Quarterly antibiogram patterns suggested that antibiotic cycling may have impacted resistance, although the small number of isolates precluded statistical analysis. Further assessment of this approach is necessary to determine its relationship to antimicrobial resistance.

Implementation of strategies to prevent and control the emergence and spread of antimicrobial-resistant microorganisms in U.S. hospitals

OBJECTIVE

To examine the extent to which the strategies recommended by the National Foundation for Infectious Diseases (NFID)-Centers for Disease Control and Prevention (CDC) co-sponsored workshop, Antimicrobial Resistance in Hospitals: Strategies to Improve Antimicrobial Use and Prevent Nosocomial Transmission of Antimicrobial-Resistant Microorganisms, have been implemented and the relationship between the degree of implementation and hospital culture, leadership, and organizational factors.

DESIGN

Survey.

SETTING

A representative sample of U.S. hospitals stratified by teaching status, bed size, and geographic region.

PARTICIPANTS

Infection control professionals.

RESULTS

Surveyed hospitals had implemented strategies to optimize the use of antimicrobials and to detect, report, and prevent transmission of antimicrobial-resistant microorganisms. Multivariate analyses found that hospitals with a greater degree of implementation of the NFID-CDC strategic goals were more likely to have management support, education of staff, and interdisciplinary groups specifically to address these issues; they were also more likely to engage in benchmarking on broader quality of care indicators.

CONCLUSIONS

Most surveyed hospitals had implemented some measures to address the NFID-CDC recommendations; however, hospitals need to do much more to improve antimicrobial use and to increase their efforts to detect, report, and control the spread of antimicrobial resistance. A supportive hospital administration must foster a culture of ongoing support, education, and interdisciplinary work groups focused on this important issue to successfully accomplish these goals.

Compliance with an infectious disease specialist's advisory consultations on targeted antibiotic usage

This study was conducted to evaluate the appropriateness of the use of targeted antibiotics, and to analyze compliance and the short-term impact of targeted antibiotic advisory consultations, as implemented in our hospital in October 2002. Targeted antibiotics included glycopeptides, carbapenems, antipseudomonal cephalosporins, and aminoglycosides. A total of 339 prescriptions were reviewed from October 2002 through March 2003. Antimicrobial utilization density (AUD), which was the defined daily dose divided by 1000 patient days, was compared quarterly. Overall, 85.6% of the prescriptions were inappropriate, with 73.7% being inappropriate for therapeutic use and 100% inappropriate for prophylactic use. The overall compliance rate of attending physicians with the antibiotic advisory consultations was 46.5%. Compliance was higher in medical services than in surgical services (64.2% vs 43.1%; P = 0.005) and for therapeutic use than for prophylactic use (54.7% vs 36.5%; P = 0.001). The use of all parenteral antibiotics in the hospital decreased, from 770.8 AUD during the first quarter in 2002 to 626.8 AUD during the second quarter in 2003 (P < 0.01). In conclusion, inappropriate antibiotic use for treatment and prophylaxis is common in our hospital. A targeted antibiotic advisory consultation may be an alternative means of ensuring more appropriate antibiotic use. However, more efficient antibiotic control measures should be developed and implemented, and prospective and continuous monitoring of antibiotic use is required.

Use of antibiotics in hospitals in south-western France

Data on the use of antibiotics were collected by means of a questionnaire from 49 hospitals in south-western France. Use was expressed as a usage density rate: number of defined daily doses (DDDs) per 1000 patient-days. The average use of antibiotics amounted to 402 DDDs per 1000 patient-days and varied between 60 and 734. In acute-care wards, the amount of antibiotic use increased with the size of the hospital: 461 DDDs per 1000 patient-days for group A (<100 beds), 510 DDDs per 1000 patient-days for group B (more than 100 and less then 300 beds) and 676 DDDs per 1000 patient-days for group C (>300 beds). The rate of use differed among different types of hospital areas and varied from 58 for psychiatry departments to more than 1273 DDDs per 1000 patient-days for the infectious diseases departments. Broad-spectrum penicillins were the most frequently prescribed antibiotics. Fluoroquinolone and third-generation cephalosporin use were relatively uniform in the three size categories. This study shows that it is possible for a hospital to benchmark its consumption with other hospitals that are similar in size. In this way, surveillance of antibiotic use can aid hospitals in targeting infection control efforts.

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.

Antimicrobial peptides in animals and their role in host defences

Domesticated animals have a large variety of antimicrobial peptides that serve as natural innate barriers limiting microbial infection or, in some instances, act as an integral component in response to inflammation or microbial infection. These peptides differ in size, composition, mechanisms of activity and range of antimicrobial specificities. They are expressed in many tissues, polymorphonuclear leukocytes, macrophages and mucosal epithelial cells. There is a small group of anionic antimicrobial peptides found in ruminants and a much larger group of cationic antimicrobial peptides found in all domesticated animals. The cationic peptides include linear, helical peptides, linear peptides rich in proline and cysteine-stabilized peptides with a beta-sheet and are commonly referred to as cathelicidins and defensins. These peptides are generally broad-spectrum for Gram-positive bacteria, Gram-negative bacteria and fungi (e.g. myeloid antimicrobial peptides, alpha-, beta-defensins, and protegrins) or are specific to one of these groups (e.g. porcine cecropin P1, Bac5, Bac7, PR-39 and prophenin).

Relationship between fluoroquinolone use and changes in susceptibility to fluoroquinolones of selected pathogens in 10 United States teaching hospitals, 1991-2000

We retrospectively examined the relationship between fluoroquinolone use and the susceptibilities of 11 bacterial pathogens to fluoroquinolones in 10 US teaching hospitals from 1991 through 2000. Statistical significance was determined by 2-way analysis of variance, with the number of isolates tested each year as a weighting factor. The analysis of baseline-to-end point change in the percentage of susceptibility and the slope of the regression line (trend line) for logit percentage of susceptibility showed that the overall percentage of susceptibility to fluoroquinolones decreased significantly during the study period (P<.05) and that change in percentage of susceptibility was significantly related to change in fluoroquinolone use (P<.05). Particularly notable were the decreases in the susceptibilities of Pseudomonas aeruginosa, Proteus mirabilis, and Escherichia coli (decreases of 25.1%, 11.9%, and 6.8%, respectively).

Marked differences in antibiotic use and resistance between university hospitals in Vilnius, Lithuania, and Huddinge, Sweden

Antibiotic use and antimicrobial resistance was compared between Vilnius and Huddinge University hospitals. Drug use data were expressed in number of defined daily doses/100 bed-days; antimicrobial resistance were given as percentages of resistant isolates. Thirty-five and 48 different antibiotic drugs were used in Vilnius and Huddinge, respectively. The overall consumption of antibiotics was 15 DDD/100 bed-days in Vilnius and 43 DDD/100 bed-days in Huddinge. Benzylpenicillin, ampicillin, and aminoglycosides were the major antibiotics in Vilnius; beta-lactamase-resistant penicillins, cefalosporins, and quinolones in Huddinge. In Vilnius, gentamicin made up one-quarter of the use. Staphylococcus aureus and Gram-negative isolates from wounds and blood were more resistant to gentamicin in Vilnius. S. aureus was more often methicillin resistant in Vilnius than in Huddinge. There was no S. aureus-resistant to vancomycin in either hospital. The vancomycin-resistant enterococci made up from 4% to 10% in Vilnius hospital, but they were not detected in Huddinge hospital (0%). The majority of Streptococcus pneumoniae isolates were sensitive to benzylpenicillin in both hospitals. The higher resistance of microorganisms to some antibiotics in Vilnius may be explained by heavy use of few antibiotics. Lower level of hygiene procedures, sampling bias, and other methodological issues may also have contributed. Guidelines for antibiotic use and hygienic procedures are now under development in Vilnius.

Effectiveness of a multifaceted infection control policy in reducing vancomycin usage and vancomycin-resistant enterococci at a tertiary care cancer centre

We undertook a prospective cohort study to evaluate the role of a multifaceted infection control policy including the use of a "vancomycin order form," in decreasing the transmission of vancomycin-resistant enterococci (VRE). In January 1997, a multifaceted infection-control policy was implemented amongst patients admitted to the M. D. Anderson Cancer Center in whom neutropenic fever developed or who were found to be colonized or infected with VRE. As part of this programme, we initiated the use of a vancomycin order form to reduce the use of empirical vancomycin. The total incidence of VRE infections declined from 0.437/1000 patient days in 1996-97 to 0.229/1000 patient days in 1998-99 (P=0.008). The VRE bloodstream infections declined from 0.338/1000 patient days in 1996-97 to 0.181/1000 patient days in 1998-99 (P=0.027). Empiric vancomycin use decreased from 416 g/1000 patient days in 1996-97 to 208 g/1000 patient days in 1998-99 (P<0.001), resulting in a decreased vancomycin cost from $2561 US dollars/1000 patient days in 1996-97 to $1195 US dollars/1000 patient days in 1997-98 (P<0.001). We conclude that a multifaceted infection control policy incorporating the use of a vancomycin order form can effectively decrease the use of empirical vancomycin and can play a role in limiting the spread of VRE in an endemic setting.

Influence of an infectious disease consulting service on quality and costs of antibiotic prescriptions in a university hospital

An infectious disease consulting service was set up at a large tertiary university hospital in 1996 to evaluate and to improve antibiotic prescription patterns. Treatment guidelines for the most common bacterial infections were implemented. On daily ward rounds antibiotic therapies without evidence of an infectious disease were stopped and inappropriate regimens were changed by an infectious disease specialist. During a 6-month prospective intervention period, 3,528 patients were studied on 13 wards of the department of internal medicine; 513 of these patients (14.5%) received antibiotic therapy. These treatment courses were evaluated as adequate in 394 cases (76.8%) and incorrect in 119 cases (23.2%). Inadequate antibiotic substances were chosen in 72 out of 119 cases (60.5%) and there was no indication for treatment in 38 out of 119 cases (32%). Pathogen-specific therapies were inadequate significantly more often than empirical antimicrobial therapies (p < 0.001). In addition, the duration of the perioperative prophylaxis could be limited to 1 d. Comparing the intervention period with a 3-month control interval without an infectious disease consulting service, a total of 31,510 Euro (including the costs for the infectious disease specialist) could be saved. No increase in infection-related mortality or length of stay was observed. These data show that an infectious disease consulting service optimizes antibiotic usage, and is cost-effective as a result of a significant cost reduction in hospitals, while not interfering with the quality of medical care.

Linezolid-Induced anemia and thrombocytopenia

Linezolid, a fluorinated oxazolidinone, is the first of a new class of antimicrobials designed to target resistant gram-positive cocci. Hematologic adverse effects, including reversible thrombocytopenia, were reported during phase III comparator-controlled trials. A 66-year-old man developed sternal osteomyelitis due to methicillin-resistant Staphylococcus aureus after undergoing coronary artery bypass graft surgery. Methicillin-resistant S. aureus bacteremia developed after several surgical debridements and courses of vancomycin failed to improve the patient's condition. Oral linezolid 600 mg twice/day was begun; 17 days later, a complete blood count revealed that his hematocrit had decreased from 37.4% to 24.8%, and his platelet count had decreased from 234 x 10(3)/mm3 to 149 x 10(3)/mm3. Both values returned to normal after linezolid was discontinued. Complete blood counts should be monitored closely in patients taking linezolid, especially if therapy continues for more than 14 days.

Antimicrobial cycling: the future or a fad?

OBJECTIVE

To assess the current evidence of the value of cycling of antimicrobials to control the emergence of resistance or to reverse existing resistance to antimicrobials.

DATA SOURCES

Articles were obtained through a MEDLiNE search of the English-language literature from 1966 to January 2000. Additionally, references from retrieved publications were reviewed to identify further articles.

STUDY SELECTION AND DATA EXTRACTION

All investigations of switching between or cycling among antimicrobials were evaluated. Studies switching between or cycling among specific drugs or classes of drugs within institutional settings were included in this review.

DATA SYNTHESIS

Studies involving cycling among different aminoglycosides suggest that, although temporary decreases in resistance can be documented, resistance usually rebounds rapidly on completion of the cycle and return to the original agent. Switching between classes of antimicrobials has produced inconsistent results and has been shown to replace resistance to one agent with resistance to another. Mathematical models using both in vitro and clinical data have suggested that, due to residual resistance in the population, cycling among drug classes is unlikely to yield long-term reductions in antimicrobial resistance, especially if a high level of antimicrobial resistance exists.

CONCLUSIONS

Cycling among different antimicrobials to reverse resistance trends is currently not supported by published literature. Cycling to prevent the emergence of resistance may ultimately be more useful; however, no studies have evaluated this concept. Well-designed prospective studies are needed to evaluate the potential clinical value of antimicrobialcycling.

Multiple antibiotic changes during the first 72 hours of hospitalization

BACKGROUND

Increasing concern about inappropriate antibiotic use prompted us to examine whether our patients were receiving frequent and perhaps unwarranted changes of antibiotic therapy.

METHODS

We evaluated antibiotic prescribing by the physicians in the Emergency Department and by those on the inpatient medical service during the first 72 hours of hospitalization in 119 patients admitted with suspected serious infections to an acute care, university-affiliated, municipal teaching hospital. The appropriateness of antibiotic prescriptions was assessed independently and retrospectively by 2 infectious disease specialists (each based at a different hospital) using a 4-grade scale (from 1 = wrong choice to 4 = appropriate). Of their evaluations of the 427 antibiotic regimens given to the 119 patients during 4 defined intervals during their first 72 hours of hospitalization, 90% agreed with each other within 1 grade. Their evaluations were then compared with the selections that had been made at each interval by the prescribing physicians.

RESULTS

Successive prescribing physicians changed the antibiotic regimens in 77% of cases during the first 24 hours and in 56% during the next 48, often without apparent clinical or microbiologic indications. By 72 hours, the 119 patients had received a mean of 3.1 +/- 1.3 (+/-SD) different antibiotics, and 40 received between 4 and 7. Only 7% of the patients had no change in the regimen prescribed originally.

CONCLUSIONS

Many patients had multiple changes of antibiotics, often unnecessarily, resulting in exposure to too many agents.

Etiology of fever and opportunities for reduction of antibiotic use in a pediatric intensive care unit

OBJECTIVE

To determine the cause of fever in critically ill children and to identify opportunities for reducing antibiotic use in this population.

DESIGN

Prospective case series.

SETTING

A tertiary-care medical-surgical pediatric intensive care unit (PICU).

PATIENTS

Children admitted to the PICU who experienced fever (axillary temperature >38.3 degrees C).

MEASUREMENTS

Consecutive children who were febrile at any point in their PICU stay were investigated over two winter seasons. Etiology of the fever was determined by physical examination and routine microbiology and radiographic tests. Three subgroups were reviewed to approximate the number of antibiotic-days that could have been reduced; namely, those with an indeterminate source, those with a documented viral infection, and those receiving a prolonged course of antibiotics. A set of standards reflecting common antibiotic use then was applied to these three patient groups.

RESULTS

Of 211 subjects, the majority (83.3%) had either a definitive or suspected focus for their fever, and nearly all of these patients were judged to have an infectious etiology. The study population received a total of 2,036 antibiotic-days. Despite the high incidence of infectious causes of fever in our subjects, however, approximately 15% of total antibiotic-days could have been reduced by applying common-use standards.

CONCLUSIONS

Fever in the PICU was usually of defined focus and infectious in origin. However, among febrile patients in the PICU, substantial opportunity exists for reduction of antibiotic use. Trials determining the safety of antibiotic reduction in this population should be pursued vigorously.

Impact of a hospital-based antimicrobial management program on clinical and economic outcomes

Inappropriate use of antimicrobial agents results in unnecessary exposure to medication, persistent or progressive infection, emergence of resistance, and increased costs. We implemented a program to control use of restricted agents while improving care. This study compared 2 major mechanisms for improving use of antimicrobial agents: (1) recommendations made by the Antimicrobial Management Team (AMT), which included a clinical pharmacist backed up by a physician from the Division of Infectious Diseases (ID), and (2) recommendations made by ID fellows. Outcome measures included appropriateness of recommendations, cure rate, number of treatment failures, and cost of care, which were assessed for 180 patients. The AMT outperformed the ID fellows in all outcomes examined by the study (including appropriateness [87% vs. 47%; P<.001], cure rate [64% vs. 42%; P=.007], and treatment failures [15% vs. 28%; P=.03]), although the differences in economic outcomes between cases managed by the AMT and those managed by the ID fellows were not statistically significant. In an academic setting with a restricted formulary, the AMT demonstrated better antimicrobial prescribing than ID fellows.