961. Pandemic Hits: Evaluation of an Antimicrobial Stewardship Program Website for Hospital Communication During the COVID-19 Pandemic

Background

Antibiotic Stewardship Programs (ASPs) assist front-line clinicians in synthesizing emerging data and establishing best practices. Our ASP team directly maintained and edited an internal web application, Duke CustomID^®, to disseminate updated guideline, policy, and drug information during COVID-19. We aimed to describe website engagement and maintenance during the dynamic pandemic period.

Methods

We performed a descriptive, time-series analysis using Google Analytics software to measure engagement with Duke CustomID^® during a 1-year pre-pandemic period through the Omicron surge: January 2019 to March 2022. We measured total page views (or “hits”), COVID-specific page hits, and days requiring COVID-specific page edits by week. Given fluctuations in hospitalization rates, we defined the primary outcome as the rate of hits divided by total hospitalizations. Weekly data were assessed graphically with positive COVID tests and COVID hospitalizations. We used negative binomial regression to quantify the association between COVID hospitalizations and hit rates and to trend engagement over time, adjusted for seasonality. We stratified data by COVID page and calculated a hit/edit ratio.

Results

Engagement with CustomID® increased during the pandemic period, especially during surges (Figure). Hits in the pre-pandemic period were median 1707 (range 1165-2354) per week, and hit rates median 1.95 per hospitalization (range 1.40-2.86). Peaks were observed in March 2020 (hit rate 4.59) and January 2022 (hit rate 3.87). On average, for every 100 COVID hospitalizations, the hit rate increased by 0.08 (0.004-0.16, p=0.04). Engagement slowly increased over the study period (relative rate week 1 versus 170: 1.15, 95% confidence interval 1.02-1.28, p=0.02). COVID page edits per week had a median of 2 (range 0-12). Adult Inpatient Guidelines and COVID Monoclonal Antibody pages had highest use (Table).

Duke CustomID Hits and Maintenance Efforts over the Pandemic

Top: COVID-specific CustomID hits per week (Green), Positive COVID tests per week (Blue) over time

Middle: Total custom ID page hits relative to total hospitalizations per week (teal), COVID hospitalizations (Red)

Bottom: Number of edits to COVID-specific CustomID pages per week, stratified by management pages and drug pages

Several dates of significance are highlighted including the Emergency Use Authorizations (EUA) for remdesivir, the COVID Vaccines, and Paxlovid

Duke CustomID COVID-19 Page Hits and Edits

COVID specific pages on Duke CustomID with total hits, edits, and ratio over the pandemic

Conclusion

Our ASP’s website was a highly utilized, practical tool for disseminating practice-changing information during the pandemic. Use increased over time and especially during surges. An electronic reference customized for local practice and rapidly updated by ASPs offers critical support for front-line clinicians.

Disclosures

Martha B. Adams, M.D., Custom Clinical Decision Support, Inc: Board Member|Custom Clinical Decision Support, Inc: Ownership Interest Richard H. Drew, PharmD MS, American College of Clinical Pharmacists: Publication royalties|Takeda: Advisor/Consultant|UpToDate: publication royalties Rebekah W. Moehring, MD, MPH, FIDSA, FSHEA, UpToDate, Inc.: Author Royalties Michael J. Smith, M.D., M.S.C.E, Merck: Grant/Research Support|Pfizer: Grant/Research Support.

1025. Utility of a Risk Assessment Model in Predicting 30-day Unplanned Hospital Readmission in Adult Patients Receiving Outpatient Parenteral Antimicrobial Therapy

Background

Outpatient parenteral antimicrobial therapy (OPAT) is used for patients that require prolonged durations of intravenous (IV) antimicrobials and who are healthy enough to receive the medications in the outpatient setting. While OPAT is both efficacious and cost-effective, hospital readmission rates are high. Durojaiye and colleagues in the UK developed a 30-day unplanned readmission risk prediction model for OPAT patients. Given differences in patient mix and methods of OPAT delivery, we validated the established risk assessment model for Duke University Health System (DUHS) patients receiving OPAT.

Methods

A retrospective review of 606 OPAT episodes of adult patients who were enrolled in the DUHS OPAT program between July 1, 2019 and February 1, 2020 was conducted. The review captured the 6 risk predictors of the established model: age, Charlson Comorbidity Score, number of admissions in the preceding 12 months, concurrent receipt of more than one IV antimicrobial agent, type of infection, and mode of OPAT delivery. Additional risk predictors were captured: aminoglycoside use, vancomycin use, OPAT delivery in a skilled nursing facility, and history of IV drug abuse. The discriminative ability of the model to predict 30-day unplanned readmission as well as 30-day OPAT-related unplanned readmission was validated with the collected data using scaled Brier score, Hosmer-Lemeshow goodness-of-fit, and area under the receiver operating curve. A logistic regression model fitted with the additional risk factors was conducted to determine their impact on the model.

Results

When comparing DUHS OPAT patients with those of the UK model, DUHS patients were sicker (mean Charlson Comorbidity Score 3 vs 1), were treated for deeper seated infections, and received OPAT through different modes. Overall the 30-day unplanned readmission rate was 20.0% (94/470), with 59.5% of those being OPAT-related. The UK model was unable to discriminate between patients with readmission and those without, both overall and OPAT-related. The additional risk factors were also non-significant between the groups and the updated model could not predict 30-day readmission risk.

Conclusion

The UK 30-day unplanned hospital readmission model did not predict patient risk of readmission for the Duke OPAT population.

Disclosures

Richard H. Drew, PharmD MS, American College of Clinical Pharmacists: Publication royalties|Takeda: Advisor/Consultant|UpToDate: publication royalties.

Conventional Antifungals for Invasive Infections Delivered by Unconventional Methods; Aerosols, Irrigants, Directed Injections and Impregnated Cement

The administration of approved antifungals via unapproved formulations or administration routes (such as aerosol, direct injection, irrigation, topical formulation and antifungal-impregnated orthopedic beads or cement) may be resorted to in an attempt to optimize drug exposure while minimizing toxicities and/or drug interactions associated with conventional (systemic) administrations. Existing data regarding such administrations are mostly restricted to uncontrolled case reports of patients with diseases refractory to conventional therapies. Attribution of efficacy and tolerability is most often problematic. This review updates prior published summaries, reflecting the most recent data and its application by available prevention and treatment guidelines for invasive fungal infections. Of the various dosage forms and antifungals, perhaps none is more widely reported than the application of amphotericin B-containing aerosols for the prevention of invasive mold infections (notably Aspergillus spp.).

51. Development and Assessment of a Process to Describe the Timing of Antibiotic Changes in Adult Inpatients

Background

Hospital antimicrobial stewardship programs (ASP) perform prospective audit and feedback to optimize use of antimicrobials; however, workflow inefficiency continues to be a distinct challenge. We developed a method to describe the volume and timing of antimicrobial changes to inform decisions on optimal timing of ASP review and intervention.

Methods

This retrospective study was performed at Duke University Hospital using anonymized antibiotic administration records from the DASON central database. Eligible antibiotic courses were administered to inpatients ≥ 18 years of age and had received ≥ 2 antibiotics administrations for ≥ 24 hours of treatment. A 2-month exploratory cohort (September to October 2017) was used to develop an antibiotic spectrum ranking (Table 1) and decision algorithm which was applied to a 1-year cohort (November 2017 to October 2018) for analysis of total change in antibiotic orders by day of the week. For each interval, the sum of antibiotic ranks was calculated and applied using specified definitions (Table 2) to determine the type of change occurring. The primary outcome was the number of total antibiotic changes that occurred on each day of the week. Secondary outcomes included the number and type (initiations, discontinuations, de-escalations, and escalations) of change. Descriptive statistics were used to describe the outcomes by day of the week.

Table 1: Antibiotic Spectrum Ranking

Table 2: Key Definitions

Results

The ranking and decision algorithm were applied to 16,993 unique antibiotic courses. Total changes occurred most on Wednesday (14,971, 16.2% [95% CI 15.7–17.1%]) and Friday (14,349, 15.6% [95% CI 15.0–16.2%]). Compared to intervals on weekdays (0.407 mean changes per patients on antibiotics [95% CI 0.401–0.413]), weekends had a lower number of changes (0.363 mean changes per patients on antibiotics [95% CI 0.349–0.377]). Initiations occurred most frequently on Tuesday (3,078, 18.1% [95% CI 16.3–19.9%]), and discontinuations on Wednesday (3,179, 18.7% [95% CI 17.4–20.5%]) (Figure 1).

Figure 1: Types of Changes per Day

Conclusion

We developed and applied a method to characterize antimicrobial changes. In our institution, the reductions in the number of changes observed on weekends provide an opportunity for ASP involvement to be incorporated and help facilitate appropriate antimicrobial changes.

Disclosures

Rebekah W. Moehring, MD, MPH, Agency for Healthcare Quality and Research (Grant/Research Support)Centers for Disease Control and Prevention (Grant/Research Support)

166. Barriers to implementing antimicrobial stewardship programs in low- or middle-income country settings: findings from a multi-site qualitative study

Background

Antimicrobial resistance has been named as one of the top ten threats to health in the world. The World Health Organization has endorsed the implementation of hosptial-based antimicrobial stewardship programs (ASPs) to reduce antimicrobial resistance. We conducted a qualitative study to determine perceived barriers to the development and implementation of ASPs in low- and middle-income countries (LMICs).

Methods

We conducted 46 interviews with medical doctors at tertiary care hospitals in Sri Lanka (22 doctors), Kenya (12), and Tanzania (12). Interviews assessed knowledge and receptiveness to ASPs and barriers to implementing ASP protocols. Interviews were conducted in English, audio recorded, and transcribed. The interviews discussed knowledge of antimicrobial resistance and ASPs, current antimicrobial prescribing practices, access to diagnostics, receptiveness to ASPs, and perceived barriers to implementing ASPs. Data analysis followed procedures of applied thematic analysis, and used NVivo software. A codebook included structural themes based on the interview questions and emerging inductive themes. Two independent reviewers coded the interviews, and the coding was combined and reviewed for consensus. Themes were synthesized, with comparisons made across the three sites.

Results

Medical doctors from all three sites discussed multiple barriers to improving antimicrobial prescribing: prohibitively expensive antimicrobials, limited antimicrobial availability, resistance to change current practices regarding antimicrobial prescribing, and limited diagnostic data. The most frequent of these barriers discussed in all three locations was limited drug availability, mentioned by 12/22 physicians in Sri Lanka, 5/12 in Tanzania and 8/12 in Kenya. Improved education was a suggested component of ASPs in all three sites: 7/22 in Sri Lanka, 6/12 in Tanzania, and 6/12 in Kenya.

Conclusion

The study highlighted several important issues in determining the next steps for the implementation of ASPs in these LMIC hospitals. Improving drug availability and improving education to change physicians’ antimicrobial prescribing practices are important targets that could be addressed by ASPs in these facilities.

Disclosures

All Authors: No reported disclosures

158. A multi-site, prospective study of antimicrobial prescribing practices in three low- or middle-income country hospitals

Background

Antimicrobial stewardship programs (ASPs) are being developed internationally to mitigate the misuse of antimicrobials. An understanding of current practices and prescribing patterns is necessary to determine targets to develop context-specific ASPs in low- and middle-income country (LMIC) hospitals.

Methods

We conducted a prospective study of patients admitted to the adult medical wards at three LMIC tertiary care centers in 2018- 2019: a 1,800-bed public hospital in Galle, Sri Lanka; a 991-bed public hospital in Eldoret, Kenya; and a 630-bed private hospital in Moshi, Tanzania. Information regarding antimicrobial therapy received during hospitalization, indications for antimicrobial therapy, and duration of antimicrobial use were extracted from the medical record.

Results

In total, 3150 patients were enrolled: 1297 in Sri Lanka, 750 in Kenya, and 1103 in Tanzania. Antimicrobial use prevalence varied between the three sites, with 56.0% of patients receiving antimicrobials during hospitalization in Sri Lanka, 56.5% in Kenya, and 35.4% in Tanzania. Third-generation cephalosporins were used most frequently in Kenya (70.0%) and Tanzania (73.1%), whereas amoxicillin/ clavulanic acid was used most frequently in Sri Lanka (48.4%). Lower respiratory tract infection was the most common indication for antimicrobial use in all three locations: 37.4% in Sri Lanka, 27.8% in Kenya, and 49.2% in Tanzania. No clear indication for antimicrobial use was documented among 11.6% patients receiving antimicrobials in Sri Lanka, 32.8% in Kenya, and 10.5% in Tanzania. In Tanzania, 8.6% of the patients had documentation of input from the microbiology or infectious diseases teams compared to less than 1% in either Sri Lanka or Kenya. Pertinent culture data related to the primary indication for antimicrobials was present in 16.1% (Sri Lanka), 6.1% (Kenya), and 7.4% (Tanzania).

Conclusion

Unclear documentation for antimicrobial use was common in all three sites and most patients on antimicrobial therapy did not have pertinent culture data. Improving documentation and the capacity of the local microbiology laboratories could be initial targets for ASPs in these LMIC hospitals.

Disclosures

All Authors: No reported disclosures

775. Comparison of Initial Vancomycin Costs and Target Attainment Between Trough- and 24-Hour Area Under the Concentration–Time Curve (AUC24)-Guided Dosing

Background

Vancomycin is the treatment-of-choice for most invasive methicillin-resistant Staphylococcus aureus (MRSA) infections. Although serum trough concentration-guided vancomycin dosing is the current standard, dosing based on AUC₂₄ to minimum inhibitory concentration ratio best predicts efficacy while often reducing trough concentrations associated with increased nephrotoxicity. Data regarding the impact of AUC₂₄-guided dosing on drug costs is sparse. We compared the relative initial acquisition cost of vancomycin when utilizing AUC₂₄- vs. trough-guided dosing. We also sought to describe current dosing practices relative to attainment of targeted vancomycin exposures.

Methods

A retrospective, single-center cohort study was performed on 200 randomly-selected hospitalized adults at Duke University Hospital (DUH) in calendar year 2017 with suspected or confirmed invasive MRSA infection and stable renal function. For the primary outcome measure, a cost-minimization analysis was performed utilizing DUH wholesale vancomycin acquisition cost through 48 hours as determined from prescribed trough- and Bayesian computer-simulated AUC₂₄-guided dosing. Descriptive statistics were utilized to characterize dosing, serum concentration monitoring practices and attainment of goal vancomycin exposures.

Results

In the 200 enrolled subjects, the median (IQR_25,75) cost difference per patient among trough- and AUC₂₄-guided dosing was $0.00 (-15.02, 15.02). Serum vancomycin troughs were labeled correctly in 54% of samples, while 20.7% exceeded 2 hours of the next scheduled dose. Mean loading doses were 21.0 mg/kg and 24.8 mg/kg, respectively. Goal steady-state troughs were achieved in 22% of subjects. Initial dosing was predicted to achieve an AUC₂₄ within 400–600 mg.hr/L in 66.5% and 100%, respectively. Troughs ≥15 mg/dL (a known risk factor for nephrotoxicity) were measured in 32.1% of trough-guided dosing regimens while predicted in 5.0% of AUC₂₄-guided dosing regimens

Conclusion

When compared with trough-, AUC₂₄-guided dosing may lead to improved attainment of vancomycin target exposures, including potential reductions in excessive and incorrectly labeled trough concentrations, without impacting drug acquisition costs.

Disclosures

All authors: No reported disclosures.

1243. Continuous vs. Intermittent Intraoperative Infusion of Cefazolin on Surgical Site Infections (SSIs) and Acute Kidney Injury in Patients Undergoing Cardiac Procedures

Background

Continuous infusion cefazolin (CI) has been investigated as a means to optimize antibiotic exposure for prophylaxis against SSI, notably in patients undergoing cardiac procedures involving cardiac bypass (CPB). However, data are limited on its impact on late SSIs and adverse events. In 6/16, the Duke University Hospital (DUH) Antimicrobial Stewardship Team implemented a program to promote CI. We compared the incidence of culture-confirmed SSIs through postoperative day 90 (POD90) between patients receiving either intermittent infusion cefazolin (INT) or CI intraoperatively. We also compared the rate of acute kidney injury (AKI) between groups.

Methods

This retrospective quasi-experimental design included adult and pediatric patients undergoing cardiac surgery at DUH between March 2014 and August 2018 and receiving intraoperative cefazolin (alone or in combination with other antibiotics). Patients were categorized as CI (having received at least 1 intraoperative CI infusion) or INT. Culture-confirmed SSIs utilizing NHSN definitions were recorded and a relative risk (RR) determined. AKI was defined as a ≥0.3 mg/dL rise in serum creatinine within 2 days postoperatively.

Results

A total of 2,172 unique surgical procedures (from 2,143 unique patients) were included. Comparisons of groups are summarized in Table 1. Rates of SSIs were 1.1% and 1.6% in the CI and INT groups, respectively (RR [95% confidence interval] for CI 0.73, [0.35, 1.52]). AKI was reported in 12.9% and 17.4% of patients, respectively.

Conclusion

We were unable to detect a difference in late SSIs between intraoperative CI and INT cefazolin. Differences observed between AKI between groups requires further investigation, but likely impacted by confounders, including pre-existing renal dysfunction.

Disclosures

All authors: No reported disclosures.

2795. Clinical and Economic Impact of a Ribavirin Intervention Program in Hematopoietic Cell and Solid-organ Transplant Recipients with Respiratory Syncytial Virus Infection

Background

While data are limited, oral ribavirin (RBV) has been shown to be a cost-effective alternative to aerosolized RBV for the treatment of respiratory syncytial virus (RSV) in immunocompromised patients with significant reductions in acquisition and administration costs. We evaluated the clinical and economic impact of an RBV intervention program at a large, academic medical center.

Methods

This single-center, retrospective cohort study evaluated hematopoietic cell and solid-organ transplant patients admitted to Duke University Hospital (DUH) with documented or suspected RSV receiving aerosolized and/or oral RBV from July 2013 to April 2018. The ID consult service approval requirement was initiated for aerosolized RBV beginning in October 2015. Education was done at this time to promote oral RBV as the preferred therapy for immunocompromised, RSV-infected adults and children. No restrictions or treatment protocols were in place prior to that time for either formulation. Clinical outcomes, adverse effects, and drug acquisition cost were collected. A cost-avoidance analysis was performed using DUH acquisition cost for actual and alternate RBV therapy.

Results

A total of 118 treatments (115 unique adult and pediatric patients) were included. Demographics were comparable between groups with and median age was 52 years in the Oral RBV and 61 years in the Aerosol RBV group. The predominant transplant type was lung (62.5% in Oral RBV and 55.6% in Aerosol RBV) followed by hematopoietic (16.7% in Oral RBV and 27% in Aerosol RBV). The median (range) duration of therapy was 4 (1–16) days for oral RBV and 5 (1–23) days for aerosolized RBV. The total cost avoidance was $2,522,915 with oral RBV. Clinical outcomes are summarized in Table 1.

Conclusion

In our large tertiary care center, the use of oral RBV led to substantial cost avoidance with clinical outcomes comparable to aerosolized RBV in immunocompromised patients. Larger prospective trials evaluating oral RBV for RSV treatment are warranted.

Disclosures

All authors: No reported disclosures.

436. Skin and Soft-tissue Infections Are a Common Reason for Potentially Inappropriate Antimicrobial Use among Inpatients in Sri Lanka

Background

Skin and soft-tissue infections (SSTI) are a common reason for antimicrobial use in the outpatient and inpatient settings. Inappropriate antimicrobial use for SSTI is common. We determined the prevalence of SSTI and associated inappropriate antimicrobial use among inpatients in Sri Lanka.

Methods

A point-prevalence study of antimicrobial use was conducted using one-day cross-sectional surveys at five public hospitals in Southern Province, Sri Lanka from Jun-August 2017. Inpatients’ medical records were reviewed for clinical data including antimicrobials prescribed. Inappropriate antimicrobial use was identified as (1) antimicrobial use discordant with guidelines by the Sri Lanka College of Microbiologists (SLCM), and (2) redundant combinations of antimicrobials.

Results

Of 1,709 surveyed patients, 935 (54.7%) received antimicrobials, of whom 779 (83.3%) had a specified or inferred indication for antimicrobial use. Among patients with an indication for antimicrobial use, SSTI was the second leading indication (181 patients, 23.2%) after lower respiratory tract infection (194, 24.9%). One-third (62, 34.2%) of patients with SSTI had a history of diabetes. Commonly used antimicrobials for SSTI included amoxicillin and clavulanic acid (40.3%), extended-spectrum penicillins (24.9%), and metronidazole (22.1%). inappropriate antimicrobial use was observed in 53.0% of SSTI patients, with redundant antibiotic therapy in 35.9% and antimicrobials discordant with SLCM guidelines in 32.6%.

Conclusion

SSTI was a common reason for antimicrobial use among inpatients in Sri Lanka, with more than half of patients receiving potentially inappropriate antimicrobial therapy. We identified targets for future antimicrobial stewardship efforts.

Disclosures

All authors: No reported disclosures.

Impact of select risk factors on treatment outcome in adults with candidemia

Background:

Studies examining relationships between patient-related factors and treatment outcome in patients with candidemia are limited and often based on all-cause mortality.

Objective:

Our purpose was to examine the impact of concurrent renal replacement therapy (RRT) and other pre-specified factors on treatment outcome among adults with candidemia.

Methods:

This Institutional Review Board (IRB)-approved, single-center, case-cohort study included patients over 18 years of age admitted to Duke University Hospital between Jun 1, 2013 and Jun 1, 2017 with a blood culture positive for Candida spp. Treatment-, patient-, and disease-specific data were collected, and outcome (success/failure) determined 90 days after the index culture. An odds ratio (OR) and 95% confidence interval (95%CI) were calculated for the following during therapy: receipt of RRT, fluconazole monotherapy regimen, intensive care unit (ICU) stay, and neutropenia.

Results:

Among the 112 encounters (from 110 unique patients) included, treatment failure occurred in 8/112 (7.1%). Demographics were comparable between outcome groups. Among 12 patients receiving concomitant RRT, only 1 patient failed therapy. With regard to treatment failure, no significant differences were observed with RRT (OR, 1.21; 95%CI, 0.14 – 10.75), fluconazole monotherapy regimen (OR, 1.59; 95%CI, 0.3-8.27), ICU stay (OR, 1.43; 95%CI, 0.32-6.29), and neutropenia (0 treatment failures).

Conclusions:

Treatment failure, receipt of concomitant RRT, and neutropenia were infrequent in patients undergoing treatment for candidemia. In our cohort, exposure to RRT, a fluconazole monotherapy regimen, ICU stay, or neutropenia during treatment did not impact treatment outcome.

Impact of automatic infectious diseases consultation on the management of fungemia at a large academic medical center

PURPOSE

The impact of automatic infectious diseases (ID) consultation for inpatients with fungemia at a large academic medical center was studied.

METHODS

In this single-center, retrospective study, the time to appropriate antifungal therapy before and after implementing a policy requiring automatic ID consultation for the management of fungemia for all patients with an inpatient positive blood culture for fungus was examined. The rates of ID consultation; the likelihood of receiving appropriate antifungal therapy; central venous catheter (CVC) removal rates; performance of ophthalmologic examinations; infection-related length of stay (LOS); rates of all-cause inhospital mortality, death, or transfer to an intensive care unit within 7 days of first culture; and inpatient cost of antifungals were also evaluated.

RESULTS

A total of 173 unique episodes (94 and 79 in the control and intervention groups, respectively) were included. Candida species were the most frequently cultured organisms, isolated from over 90% of patients in both groups. No differences were observed between the control and intervention groups in time to appropriate therapy, infection-related LOS, or time to CVC removal. However, patients in the intervention group were more likely than those in the control group to receive appropriate antifungal therapy (p = 0.0392), undergo ophthalmologic examination (p = 0.003), have their CVC removed (p = 0.0038), and receive ID consultation (p = 0.0123). Inpatient antifungal costs were significantly higher in the intervention group (p = 0.0177).

CONCLUSION

While automatic ID consultation for inpatients with fungemia did not affect the time to administration of appropriate therapy, improvement was observed for several process indicators, including rates of appropriate antifungal therapy selection, time to removal of CVCs, and performance of ophthalmologic examinations.

Evaluation of a vancomycin dosing nomogram in obese patients weighing at least 100 kilograms

Background

There remains variability in both practice and evidence related to optimal initial empiric dosing strategies for vancomycin.

Objective

Our primary objective was to describe the percentage of obese patients receiving vancomycin doses consistent with nomogram recommendations achieving targeted initial steady-state serum vancomycin concentrations. Secondary objectives were to describe the primary endpoint in subgroups based on patient weight and estimated creatinine clearance, to describe the rate of supratherapeutic vancomycin accumulation following an initial therapeutic trough concentration, and to describe the rate of vancomycin-related adverse events.

Methods

This single-center, IRB-approved, retrospective cohort included adult patients ≥ 100 kilograms total body weight with a body mass index (BMI) >30 kilograms/m2 who received a stable nomogram-based vancomycin regimen and had at least one steady-state vancomycin trough concentration. Data collected included vancomycin regimens and concentrations, vancomycin indication, serum creatinine, and vancomycin-related adverse events. Patients were divided into two cohorts by goal trough concentration: 10-15 mcg/mL and 15-20 mcg/mL.

Results

Of 325 patients screened, 85 were included. Goal steady-state concentrations were reached in 42/85 (49.4%) of total patients.

Conclusions

Achievement of initial steady-state vancomycin serum concentrations in the present study (approximately 50%) was consistent with the use of published vancomycin dosing nomograms.

Influence of Reported Penicillin Allergy on Mortality in MSSA Bacteremia

Background

Penicillin allergy frequently impacts antibiotic choice. As beta-lactams are superior to vancomycin in treating methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, we examined the effect of reported penicillin allergy on clinical outcomes in patients with MSSA bacteremia.

Methods

In this retrospective cohort study of adults with MSSA bacteremia admitted to a large tertiary care hospital, outcomes were examined according to reported penicillin allergy. Primary outcomes included 30-day and 90-day mortality rates. Multivariable regression models were developed to quantify the effect of reported penicillin allergy on mortality while adjusting for potential confounders.

Results

From 2010 to 2015, 318 patients with MSSA bacteremia were identified. Reported penicillin allergy had no significant effect on adjusted 30-day mortality (odds ratio [OR], 0.73; 95% confidence interval [CI], 0.29-1.84; P = .51). Patients with reported penicillin allergy were more likely to receive vancomycin (38% vs 11%, P < .01), but a large number received cefazolin regardless of reported allergy (29 of 66, 44%). Mortality rates were highest among nonallergic patients receiving vancomycin (22.6% vs 7.4% for those receiving beta-lactams regardless of reported allergy, P < .01). In multivariable analysis, beta-lactam receipt was most strongly associated with survival (OR, 0.26; 95% CI, 0.12-0.54).

Conclusions

Reported penicillin allergy had no significant effect on 30- or 90-day mortality. Non-penicillin-allergic patients receiving vancomycin for treatment of MSSA bacteremia had the highest mortality rates overall. Receipt of a beta-lactam was the strongest predictor of survival. These results underscore the importance of correct classification of patients with penicillin allergy and appropriate treatment with a beta-lactam when tolerated.

Risk factors for healthcare-associated Clostridium difficile infection in pediatric hematopoietic stem cell transplant recipients

Background

Limited published literature exists to identify unique risk factors for Clostridium difficile infection (CDI) in pediatric hematopoietic stem cell transplantation (HSCT) recipients. Our objective was to describe the epidemiology of CDI in pediatric patients undergoing HSCT and to identify potential risk factors for CDI.

Methods

This IRB-waived, single-center retrospective review included Duke University Hospital (DUH) patients 12 months of age or older admitted to pediatrics between March 1, 2012 and August 23, 2016 undergoing initial HSCT during the index hospitalization. The primary endpoint (PCR-confirmed CDI within 100 days post-transplantation) was characterized using descriptive statistics. Transplant type, prior CDI history, days of total parenteral nutrition (TPN), and antibiotic use intensity scores were compared between occurrence groups using Pearson’s chi-square, Wilcoxon rank-sum or Student’s t tests as appropriate.

Results

207 subjects (most Caucasian [55%] and male [61%]) were included, and 15 (7.2%) died. CDI occurred in 24 (12%) within a median (interquartile range) of 35 (9, 47) days since HSCT, and most (92%) were hospital-onset. All cases were healthcare-associated and mild-moderate in severity. None of the patients experienced CDI-related complications. CDI-positive and CDI-negative patients were similar with regards to demographics. Higher median (adjusted) days of TPN (80.6 vs. 29, P < 0.0001) and antibiotic use intensity scores (382.8 vs. 191.0, P < 0.0001), respectively, were associated with CDI. No significant differences between these groups were observed with regard to transplant type (P = 0.28) and prior CDI history (P = 0.10).

Conclusion

CDI occurred in 12% of pediatric patients within 100 days of undergoing initial HSCT. Onset of this mild-moderate, uncomplicated disease occurred within a median of 35 days and commonly during hospitalization. Patients with CDI were more likely to have increased use of TPN and a higher antibiotic use intensity score.

Disclosures

All authors: No reported disclosures.

Could Risk Assessment for Non-albicans Candida Improve Empiric Treatment for Invasive Candidiasis?

The changing epidemiology of invasive candidiasis, along with concerns for the emergence of drug resistance, necessitates the identification of patients at increased risk of non-albicans Candida (NAC) to optimize selection of antifungal therapy. The major findings of a study regarding the demographic characteristics, costs, and outcomes of nonneutropenic patients with candidemia due to NAC are discussed. Given available treatment options, such risk assessment is most relevant to initial empiric therapy in stable patients without neutropenia who might be candidates for initial therapy with an azole (eg, fluconazole). The study's investigators reinforce the need for timely antifungal therapy for patients with candidemia.

Role of isavuconazole in the treatment of invasive fungal infections

Despite recent advances in both diagnosis and prevention, the incidence of invasive fungal infections continues to rise. Available antifungal agents to treat invasive fungal infections include polyenes, triazoles, and echinocandins. Unfortunately, individual agents within each class may be limited by spectrum of activity, resistance, lack of oral formulations, significant adverse event profiles, substantial drug–drug interactions, and/or variable pharmacokinetic profiles. Isavuconazole, a second-generation triazole, was approved by the US Food and Drug Administration in March 2015 and the European Medicines Agency in July 2015 for the treatment of adults with invasive aspergillosis (IA) or mucormycosis. Similar to amphotericin B and posaconazole, isavuconazole exhibits a broad spectrum of in vitro activity against yeasts, dimorphic fungi, and molds. Isavuconazole is available in both oral and intravenous formulations, exhibits a favorable safety profile (notably the absence of QTc prolongation), and reduced drug–drug interactions (relative to voriconazole). Phase 3 studies have evaluated the efficacy of isavuconazole in the management of IA, mucormycosis, and invasive candidiasis. Based on the results of these studies, isavuconazole appears to be a viable treatment option for patients with IA as well as those patients with mucormycosis who are not able to tolerate or fail amphotericin B or posaconazole therapy. In contrast, evidence of isavuconazole for invasive candidiasis (relative to comparator agents such as echinocandins) is not as robust. Therefore, isavuconazole use for invasive candidiasis may initially be reserved as a step-down oral option in those patients who cannot receive other azoles due to tolerability or spectrum of activity limitations. Post-marketing surveillance of isavuconazole will be important to better understand the safety and efficacy of this agent, as well as to better define the need for isavuconazole serum concentration monitoring.

Risk factors associated with unfavorable short-term treatment outcome in patients with documented Pseudomonas aeruginosa infection

BACKGROUND

Invasive infections with Pseudomonas aeruginosa (PA) are associated with significant morbidity and mortality. While risk factors for mortality have been identified, their influence on short-term outcomes impacting treatment selection has not been reported.

OBJECTIVES

The objective of this study was to evaluate the relationship between select patient- and treatment-related factors and short-term outcomes in patients with PA pneumonia and/or bacteremia.

SETTING

Large academic medical center in the United States.

METHODS

This IRB-approved single-center, retrospective case-cohort study included patients >18 years of age with culture-confirmed PA bacteremia and/or pneumonia receiving antimicrobial agent(s) active against PA.

MAIN OUTCOME MEASURE

Risk of unfavorable short-term treatment result.

RESULTS

The population consisted of 117 patients (40 [34 %] and 77 [66 %] in the unfavorable and not-unfavorable groups, respectively). Baseline characteristics including age (mean of 63 years), gender (55 % male), Charlson score, creatinine clearance, and body mass index were comparable between groups. Piperacillin/tazobactam was the most common monotherapy antibiotic (46 and 33 % in unfavorable and not-unfavorable groups, respectively). Combination therapy primarily consisted of a beta-lactam plus ciprofloxacin in both unfavorable (10 %) and not-unfavorable (20 %) outcome groups. The preliminary regression model indicated that SIRS, direct ICU admission, and vasopressor therapy were associated with an unfavorable outcome. In addition, patients who received more than two active antimicrobials had a reduced risk of an unfavorable outcome. The final regression model revealed that vasopressor therapy (odds ratio [OR] 6.0; 95 % confidence interval [95 % CI] 2.3, 17) was associated with an unfavorable outcome, while receipt of greater than two active antibiotics was associated with a reduced risk of an unfavorable outcome (OR 0.26; 95 % CI 0.07, 0.83).

CONCLUSIONS

Treatment with more than two agents with activity against PA was associated with a reduced risk of an unfavorable short-term treatment outcome in patients with bacteremia and/or pneumonia.

Clinical effectiveness of posaconazole versus fluconazole as antifungal prophylaxis in hematology-oncology patients: a retrospective cohort study

In preventing invasive fungal disease (IFD) in patients with acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS), clinical trials demonstrated efficacy of posaconazole over fluconazole and itraconazole. However, effectiveness of posaconazole has not been investigated in the United States in real-world setting outside the environment of controlled clinical trial. We performed a single-center, retrospective cohort study of 130 evaluable patients ≥18 years of age admitted to Duke University Hospital between 2004 and 2010 who received either posaconazole or fluconazole as prophylaxis during first induction or first reinduction chemotherapy for AML or MDS. The primary endpoint was possible, probable, or definite breakthrough IFD. Baseline characteristics were well balanced between groups, except that posaconazole recipients received reinduction chemotherapy and cytarabine more frequently. IFD occurred in 17/65 (27.0%) in the fluconazole group and in 6/65 (9.2%) in the posaconazole group (P = 0.012). Definite/probable IFDs occurred in 7 (10.8%) and 0 patients (0%), respectively (P = 0.0013). In multivariate analysis, fluconazole prophylaxis and duration of neutropenia were predictors of IFD. Mortality was similar between groups. This study demonstrates superior effectiveness of posaconazole over fluconazole as prophylaxis of IFD in AML and MDS patients. Such superiority did not translate to reductions in 100-day all-cause mortality.

Utility of a clinical risk factor scoring model in predicting infection with extended-spectrum β-lactamase-producing enterobacteriaceae on hospital admission

OBJECTIVE

To validate the utility of a previously published scoring model (Italian) to identify patients infected with community-onset extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-EKP) and develop a new model (Duke) based on local epidemiology.

METHODS

This case-control study included patients 18 years of age or more admitted to Duke University Hospital between January 1, 2008, and December 31, 2010, with culture-confirmed infection due to an ESBL-EKP (cases). Uninfected controls were matched to cases (3:1). The Italian model was applied to our patient population for validation. The Duke model was developed through logistic-regression-based prediction scores calculated on variables independently associated with ESBL-EKP isolation. Sensitivities and specificities at various point cutoffs were determined, and determination of the area under the receiver operating characteristic curve (ROC AUC) was performed.

RESULTS

A total of 123 cases and 375 controls were identified. Adjusted odds ratios and 95% confidence intervals for variables previously identified in the Italian model were as follows: hospitalization (3.20 [1.62-6.55]), transfer (4.31 [2.15-8.78]), urinary catheterization (5.92 [3.09-11.60]), β-lactam and/or fluoroquinolone therapy (3.76 [2.06-6.95]), age 70 years or more (1.55 [0.79-3.01]), and Charlson Comorbidity Score of 4 or above (1.06 [0.55-2.01]). Sensitivity and specificity were, respectively, more than or equal to 95% and less than or equal to 47% for scores 3 or below and were less than or equal to 50% and more than or equal to 96% for scores 8 or above. The ROC AUC was 0.88. Variables identified in the Duke model were as follows: hospitalization (2.63 [1.32-5.41]), transfer (5.30 [2.67-10.71]), urinary catheterization (6.89 [3.62-13.38]), β-lactam and/or fluoroquinolone therapy (3.47 [1.91-6.41]), and immunosuppression (2.34 [1.14-4.80]). Sensitivity and specificity were, respectively, more than or equal to 94% and less than or equal to 65% for scores 3 or below and were less than or equal to 58% and more than or equal to 95% for scores 8 or above. The ROC AUC was 0.89.

CONCLUSION

While the previously reported model was an excellent predictor of community-onset ESBL-EKP infection, models utilizing factors based on local epidemiology may be associated with improved performance.

Constructing unit-specific empiric treatment guidelines for catheter-related and primary bacteremia by determining the likelihood of inadequate therapy

This study aimed to determine the feasibility of using likelihood of inadequate therapy (LIT), a parameter calculated by using pathogen frequency and in vitro susceptibility for determination of appropriate empiric antibiotic therapy for primary bloodstream infections. Our study demonstrates that LIT may reveal differences in traditional antibiograms.

Ceftaroline fosamil for treatment of community-acquired pneumonia: findings from FOCUS 1 and 2 and potential role in therapy

Cephalosporins have been widely used over the last few decades (often as first-line antibiotic therapy) for numerous infections, owing primarily to their broad spectrum of microbiologic activity and favorable safety profile. Current Infectious Diseases Society of America guidelines identify a third-generation cephalosporin in combination with a macrolide antibiotic as an option for treatment of hospitalized adult patients with community-acquired pneumonia (CAP) outside the intensive care unit setting. Although ceftriaxone is a frequently used agent for CAP, increasing incidence of multidrug-resistant Streptococcus pneumoniae and concerns regarding poor outcomes associated with ineffective therapy have prompted the search for a well-tolerated treatment alternative that is effective against bacteria that can cause CAP. Ceftaroline fosamil, the prodrug of ceftaroline, is a new extended-spectrum cephalosporin that exhibits time-dependant bactericidal activity against numerous Gram-negative and Gram-positive organisms, including methicillin-resistant Staphylococcus aureus and penicillin-resistant S. pneumoniae. Notable exceptions include Pseudomonas spp. and Gram-negative organisms that produce extended-spectrum β-lactamases or carbapenemases. Two large Phase III clinical trials (FOCUS 1 and 2) reported that ceftaroline fosamil was well tolerated, with a clinical cure rate of CAP that was noninferior to that with ceftriaxone in nonintensive care unit adult inpatients with moderately severe (Pneumonia Outcomes Research Team score of III or IV) community-acquired pneumonia.

Application of antimicrobial stewardship to optimise management of community acquired pneumonia

The aim of this study was to review the application of antimicrobial stewardship principles to the management of community-acquired pneumonia (CAP). Data from 14 published clinical studies, meta-analyses and practice guidelines regarding the application of antimicrobial stewardship strategies to the management of CAP were identified and analysed. In the context of CAP, application of stewardship strategies (alone or in combination) has been shown to increase physician awareness of guidelines, improve appropriate antimicrobial use and reduce unnecessary antimicrobial prescribing. In addition, application has had a profound favourable impact on patient outcomes, including decreased 30-day mortality and in-hospital mortality rates, reduced length of hospital stay, reduced treatment failure rates and reduced healthcare costs. Antimicrobial stewardship programmes have been demonstrated to successfully increase the level of appropriate antibiotic prescribing, reduce pathogen resistance and improve clinical outcomes in the management of CAP within hospitals. Studies have also shown that adherence to evidence-based guidelines, even at the level of the individual clinician, can have a profound and positive impact on patient outcomes and healthcare costs. Adherence to evidence-based guidelines can have a profound and positive impact on patient outcomes and healthcare costs.

Overview of treatment options for invasive fungal infections

The introduction of several new antifungals has significantly expanded both prophylaxis and treatment options for invasive fungal infections (IFIs). Relative to amphotericin B deoxycholate, lipid-based formulations of amphotericin B have significantly reduced the incidence of nephrotoxicity, but at a significant increase in drug acquisition cost. Newer, broad-spectrum triazoles (notably voriconazole and posaconazole) have added significantly to both the prevention and treatment of IFIs, most notably Aspergillus spp. (with voriconazole) and the treatment of some emerging fungal pathogens. Finally, a new class of parenteral antifungals, the echinocandins, is employed most frequently against invasive candidal infections. While the role of these newer agents continues to evolve, this review summarizes the activity, safety and clinical applications of agents most commonly employed in the treatment of IFIs.

Potential role of tigecycline in the treatment of community-acquired bacterial pneumonia

Tigecycline is a member of the glycylcycline class of antimicrobials, which is structurally similar to the tetracycline class. It demonstrates potent in vitro activity against causative pathogens that are most frequently isolated in patients with community-acquired bacterial pneumonia (CABP), including (but not limited to) Streptococcus pneumoniae (both penicillin-sensitive and -resistant strains), Haemophilus influenzae and Moraxella catarrhalis (including β-lactamase-producing strains), Klebsiella pneumoniae, and ‘atypical organisms’ (namely Chlamydophila pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila). Comparative randomized clinical trials to date performed in hospitalized patients receiving tigecycline 100 mg intravenous (IV) × 1 and then 50 mg IV twice daily thereafter have demonstrated efficacy and safety comparable to the comparator agent. Major adverse effects were primarily gastrointestinal in nature. Tigecycline represents a parenteral monotherapy option in hospitalized patients with CABP (especially in patients unable to receive respiratory fluoroquinolones). However, alternate and/or additional therapies should be considered in patients with more severe forms of CABP in light of recent data of increased mortality in patients receiving tigecycline for other types of severe infection.

Echinocandin pharmacodynamics: review and clinical implications

Echinocandins have made a significant impact in the treatment of select invasive fungal infections, most notably invasive candidiasis and aspergillosis. However, treatment outcomes for such infections are still less than optimal, prompting an examination of dosing and administration techniques in an attempt to exploit known pharmacodynamic properties and improve outcomes. Echinocandins generally exhibit concentration-dependent, fungicidal activity against Candida spp. and fungistatic activity against Aspergillus spp. However, increasing drug concentrations of echinocandins above the organism's MIC may result in a paradoxical increase in fungal growth as demonstrated in some in vitro and in vivo models (known most commonly as the 'Eagle effect'). Therefore, the potential impact of dose escalations on improving the clinical efficacy of echinocandins based on in vitro and animal models are uncertain and are still being evaluated. In addition, such strategies have to consider the potential for increased treatment-related toxicities and costs. To date, published clinical studies (both superiority and non-inferiority) demonstrating the potential for dose-related improvements in treatment outcomes have been limited to mucocutaneous and oesophageal candidiasis. Further research is needed to determine if a role exists for optimizing echinocandin pharmacodynamics in various clinical settings.

Recommendations for training and certification for pharmacists practicing, mentoring, and educating in infectious diseases pharmacotherapy

Recently created guidelines for the development of institutional antimicrobial stewardship programs recommend that a pharmacist with infectious diseases training be included as a core member of the antimicrobial stewardship team. However, training and certification requirements for infectious diseases-trained clinical pharmacists have not been established. Although pharmacists have nurtured their interest in infectious diseases by self-directed learning or on-the-job experiences, this mode of training is not considered feasible or sufficient for reliable training of future clinical specialists in infectious diseases. This document, therefore, is forward looking and provides overarching recommendations for future training and certification of pharmacists practicing, mentoring, and educating in infectious diseases pharmacotherapy, with the recognition that full implementation may take several years. We recommend that future pharmacists wishing to obtain a clinical position as an infectious diseases-trained pharmacist should complete a postgraduate year (PGY) 1 residency and a PGY2 residency in infectious diseases, that practitioners become board-certified pharmacotherapy specialists, that a certification examination in infectious diseases be developed, that practitioners maintain a portfolio of educational experiences to maintain qualifications, that current nonaccredited training programs seek accreditation, and that employers and academicians recognize the desirability of these qualifications in hiring decisions.