The prevalence of gram-negative bacteria with difficult-to-treat resistance and utilization of novel ß-lactam antibiotics in the southeastern United States.

Objective: To evaluate temporal trends in the prevalence of gram-negative bacteria (GNB) with difficult-to-treat resistance (DTR) in the southeastern United States. Secondary objective was to examine the use of novel ß-lactams for GNB with DTR by both antimicrobial use (AU) and a novel metric of adjusted AU by microbiological burden (am-AU). Design: Retrospective, multicenter, cohort. Setting: Ten hospitals in the southeastern United States. Methods: GNB with DTR including Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter spp. from 2015 to 2020 were tracked at each institution. Cumulative AU of novel ß-lactams including ceftolozane/tazobactam, ceftazidime/avibactam, meropenem/vaborbactam, imipenem/cilastatin/relebactam, and cefiderocol in days of therapy (DOT) per 1,000 patient-days was calculated. Linear regression was utilized to examine temporal trends in the prevalence of GNB with DTR and cumulative AU of novel ß-lactams. Results: The overall prevalence of GNB with DTR was 0.85% (1,223/143,638) with numerical increase from 0.77% to 1.00% between 2015 and 2020 (P = .06). There was a statistically significant increase in DTR Enterobacterales (0.11% to 0.28%, P = .023) and DTR Acinetobacter spp. (4.2% to 18.8%, P = .002). Cumulative AU of novel ß-lactams was 1.91 ± 1.95 DOT per 1,000 patient-days. When comparing cumulative mean AU and am-AU, there was an increase from 1.91 to 2.36 DOT/1,000 patient-days, with more than half of the hospitals shifting in ranking after adjustment for microbiological burden. Conclusions: The overall prevalence of GNB with DTR and the use of novel ß-lactams remain low. However, the uptrend in the use of novel ß-lactams after adjusting for microbiological burden suggests a higher utilization relative to the prevalence of GNB with DTR.

Application of Precision Medicine Concepts in Ambulatory Antibiotic Management of Acute Pyelonephritis.

Acute pyelonephritis (APN) is a relatively common community-acquired infection, particularly in women. The early appropriate antibiotic treatment of this potentially life-threatening infection is associated with improved outcomes. The international management guidelines for complicated urinary tract infections and APN recommend using oral antibiotics with <10% resistance among urinary pathogens. However, increasing antibiotic resistance rates among Escherichia coli and other Enterobacterales to fluoroquinolones, trimethoprim-sulfamethoxazole (TMP-SMX), and beta-lactams has left patients without reliable oral antibiotic treatment options for APN. This narrative review proposes using precision medicine concepts to improve empirical antibiotic therapy for APN in ambulatory settings. Whereas resistance rates to a particular antibiotic class may exceed 10% at the population-based level, the predicted antibiotic resistance rates based on patient-specific risk factors fall under 10% in many patients with APN on the individual level. The utilization of clinical tools for the prediction of fluoroquinolones, TMP-SMX, and third-generation cephalosporin resistance improves the ambulatory antibiotic management of APN. It may also reduce the need to switch antibiotic therapy later based on the in vitro antibiotic susceptibility testing results of bacterial isolates in urinary cultures. This approach may mitigate the burden of increasing antibiotic resistance in the community by ensuring that the initial antibiotic prescribed has the highest likelihood of treating APN appropriately.

Intravenous versus Partial Oral Antibiotic Therapy in the Treatment of Uncomplicated Bloodstream Infection Due to Streptococcus Species.

This retrospective cohort study examines effectiveness of partial oral antibiotic regimens in uncomplicated bloodstream infections (BSIs) due to Streptococcus species compared to standard intravenous therapy. Adult patients with uncomplicated streptococcal BSIs from April 2016 to June 2020 in seven hospitals in South Carolina, USA, were evaluated. Multivariate Cox proportional hazards regression was used to examine the time to treatment failure within 90 days of a BSI after adjustment for the propensity to receive partial oral therapy. Multivariate linear regression was used to examine the hospital length of stay (HLOS). Among the 222 patients included, 99 received standard intravenous antibiotics and 123 received partial oral therapy. Of the standard intravenous therapy group, 46/99 (46.5%) required outpatient parenteral antibiotic therapy (OPAT). There was no difference in the risk of treatment failure between partial oral and standard intravenous therapy (hazards ratio 0.53, 95% CI 0.18, 1.60; p = 0.25). Partial oral therapy was independently associated with a shorter HLOS after adjustments for the propensity to receive partial oral therapy and other potential confounders (-2.23 days, 95% CI -3.53, -0.94; p < 0.001). Transitioning patients to oral antibiotics may be a reasonable strategy in the management of uncomplicated streptococcal BSIs. Partial oral therapy does not seem to have a higher risk of treatment failure and may spare patients from prolonged hospitalizations and OPAT complications.

Optimization of Empirical Antimicrobial Therapy in Enterobacterales Bloodstream Infection Using the Extended-Spectrum Beta-Lactamase Prediction Score.

Clinical tools for the prediction of antimicrobial resistance have been derived and validated without examination of their implementation in clinical practice. This study examined the impact of utilization of the extended-spectrum beta-lactamase (ESBL) prediction score on the time to initiation of appropriate antimicrobial therapy for bloodstream infection (BSI). The quasi-experimental cohort study included hospitalized adults with BSI due to ceftriaxone-resistant (CRO-R) Enterobacterales at three community hospitals in Columbia, South Carolina, USA before (January 2010 to December 2013) and after (January 2014 to December 2019) implementation of an antimicrobial stewardship intervention. In total, 45 and 101 patients with BSI due to CRO-R Enterobacterales were included before and after the intervention, respectively. Overall, the median age was 66 years, 85 (58%) were men, and 86 (59%) had a urinary source of infection. The mean time to appropriate antimicrobial therapy was 78 h before and 46 h after implementation of the antimicrobial stewardship intervention (p = 0.04). Application of the ESBL prediction score as part of an antimicrobial stewardship intervention was associated with a significant reduction in time to appropriate antimicrobial therapy in patients with BSI due to CRO-R Enterobacterales. Utilization of advanced rapid diagnostics may be necessary for a further reduction in time to appropriate antimicrobial therapy in this population.

Show me the data: A statewide comparative report of National Healthcare Safety Network (NHSN) Antimicrobial Use Option standardized antimicrobial administration ratios (SAARs).

The Antimicrobial Stewardship Collaborative of South Carolina created quarterly Comparative SAAR Analysis Reports based on standardized antimicrobial administration ratio (SAAR) data from the NHSN Antimicrobial Use (AU) Option. These reports provide SAAR histograms and site-specific feedback to participating facilities in South Carolina. They were created to improve antimicrobial use throughout the state, especially in rural regions.

A Baker's Dozen of Top Antimicrobial Stewardship Intervention Publications in Non-Hospital Care Settings in 2021.

The scope of antimicrobial stewardship programs has expanded beyond the acute hospital setting. The need to optimize antimicrobial use in emergency departments, urgent, primary, and specialty care clinics, nursing homes, and long-term care facilities prompted the development of core elements of stewardship programs in these settings. Identifying the most innovative and well-designed stewardship literature in these novel stewardship areas can be challenging. The Southeastern Research Group Endeavor (SERGE-45) network evaluated antimicrobial stewardship-related, peer-reviewed literature published in 2021 that detailed actionable interventions specific to the nonhospital setting. The top 13 publications were summarized following identification using a modified Delphi technique. This article highlights the selected interventions and may serve as a key resource for expansion of antimicrobial stewardship programs beyond the acute hospital setting.

Temporal Association between Influenza Vaccination Coverage and Ambulatory Antibiotic Use in Children.

In this population-based retrospective cohort study, increased influenza vaccination coverage was temporally associated with a reduction in ambulatory antibiotic use in children. After adjustment for yearly vaccine effectiveness, antibiotic prescription rate declined by 3/1000 person-months for each 1% increase in influenza vaccination coverage between 2012 and 2017 in South Carolina (P < 0.001).

Evaluation of early clinical failure criteria in Enterococcus species bloodstream infection.

PURPOSE: Early clinical failure criteria (ECFC) were recently introduced to predict unfavorable outcomes in patients with Gram-negative bloodstream infections (BSI). ECFC include hypotension, tachycardia, tachypnea or mechanical ventilation, altered mental status, and leukocytosis evaluated at 72-96 h after BSI. The aim of this retrospective cohort study was to assess performance of ECFC in predicting 28-day mortality in Enterococcus species BSI. METHODS: Hospitalized adults with Enterococcus species BSI at Prisma Health hospitals from 1 January 2015 to 31 July 2018 were identified. Multivariate logistic regression was used to determine the association between ECFC and 28-day mortality. Area under the receiver operating characteristic (AUROC) curve was used to measure model discrimination. RESULTS: Among 157 patients, 28 (18%) died within 28 days of BSI. After adjustments in multivariate model, the risk of 28-day mortality increased in the presence of each additional ECFC (OR 1.6, 95% CI 1.2-2.3, p = 0.005). Infective endocarditis (OR 3.9, 95% CI 1.4-10.7, p = 0.01) was independently associated with 28-day mortality. AUROC curve of ECFC model in predicting 28-day mortality was 0.74 with ECFC of 2 identified as the best breakpoint. Mortality was 8% in patients with ECFC < 2 compared to 33% in those with ECFC ≥ 2 (p < 0.001). CONCLUSION: ECFC had good discrimination in predicting 28-day mortality in patients with Enterococcus species BSI. These criteria may have utility in future clinical investigations.

Change in Antimicrobial Use During COVID-19 Pandemic in South Carolina Hospitals: A Multicenter Observational Cohort Study.

OBJECTIVES: This retrospective cohort study examined the impact of the pandemic on antimicrobial use (AU) in South Carolina hospitals. METHODS: Antimicrobial use in days of therapy (DOT) per 1000 days-present was evaluated in 17 hospitals in South Carolina. Matched-pairs mean difference was used to compare AU during the pandemic (March-June 2020) with that during the same months in 2019 in hospitals that did and did not admit patients with COVID-19. RESULTS: There was a 6.6% increase in overall AU in the seven hospitals that admitted patients with COVID-19 (from 530.9 to 565.8; mean difference (MD) 34.9 DOT/1000 days-present; 95% CI 4.3, 65.6; P = 0.03). There was no significant change in overall AU in the remaining 10 hospitals that did not admit patients with COVID-19 (MD 6.0 DOT/1000 days-present; 95% CI -55.5, 67.6; P = 0.83). Most of the increase in AU in the seven hospitals that admitted patients with COVID-19 was observed in broad-spectrum antimicrobial agents. A 16.4% increase was observed in agents predominantly used for hospital-onset infections (from 122.3 to 142.5; MD 20.1 DOT/1000 days-present; 95% CI 11.1, 29.1; P = 0.002). There was also a 9.9% increase in the use of anti-methicillin-resistant Staphylococcus aureus (MRSA) agents (from 66.7 to 73.3; MD 6.6 DOT/1000 days-present; 95% CI 2.3, 10.8; P = 0.01). CONCLUSION: The COVID-19 pandemic appears to drive overall and broad-spectrum antimicrobial use in South Carolina hospitals admitting patients with COVID-19. Additional antimicrobial stewardship resources are needed to curtail excessive antimicrobial use in hospitals to prevent subsequent increases in antimicrobial resistance and Clostridioides difficile infection rates, given the continuing nature of the pandemic.

Less common bacterial, fungal and viral infections: review of management in the pregnant patient.

This review is a comprehensive summary of treatment options for pregnant patients with less common bacterial, fungal, and viral infections. It offers guidance to clinicians based on the most recently published evidence-based research and expert recommendations. A search of MEDLINE (inception to March 2021) and the CDC website was performed. Liposomal amphotericin B is the preferred therapy for cryptococcosis, histoplasmosis, oesophageal candidiasis, and coccidioidomycosis, especially during the first trimester due to teratogenic concerns with azole antifungals. For oral candidiasis, clotrimazole troches or miconazole mucoadhesive buccal tablets are recommended. A ß-lactam antimicrobial is preferred over doxycycline for various manifestations of Lyme disease and the drug of choice for Pneumocystis pneumonia is trimethoprim/sulfamethoxazole. Acyclovir is the preferred antiviral for varicella zoster virus. Fluoroquinolones, macrolides, and aminoglycosides should be avoided if possible and there are alternate agents available for an effective treatment regimen. There is a scarcity of clinical data in pregnant patients with less common bacterial, fungal and viral infections. This population lacks definitive recommendations in many clinical practice guidelines. The key to optimizing therapy is a comprehensive review of the available evidence and a careful balance of risks and benefits before final treatment decisions.

Impact of follow up blood cultures on outcomes of patients with community-onset gram-negative bloodstream infection.

BACKGROUND: The role of follow up blood cultures (FUBC) in the management of gram-negative bloodstream infection (GN-BSI) remains controversial. This retrospective cohort study examines the association between obtaining FUBC and mortality in GN-BSI. METHODS: Hospitalized adults with community-onset GN-BSI at Prisma Health-Midlands hospitals in South Carolina, USA from January 1, 2010 to June 30, 2015 were identified. Patients who died or were discharged from hospital within 72 h were excluded to minimize impact of survival and selection biases on results, respectively. Multivariate Cox proportional hazards regression was used to examine association between obtaining FUBC and 28-day all-cause mortality after adjustment for the propensity to obtain FUBC. FINDINGS: Among 766 patients with GN-BSI, 219 (28.6%) had FUBC obtained and 15 of 219 (6.8%) FUBC were persistently positive. Overall, median age was 67 years, 438 (57%) were women, 457 (60%) had urinary source of infection, and 426 (56%) had BSI due to Escherichia coli. Mortality was significantly lower in patients who had FUBC obtained than in those who did not have FUBC (6.3% vs. 11.7%, log-rank p = 0.03). Obtaining FUBC was independently associated with reduced mortality (hazards ratio 0.47, 95% confidence intervals: 0.23-0.87; p = 0.02) after adjustments for age, chronic comorbidities, acute severity of illness, appropriateness of empirical antimicrobial therapy, and propensity to obtain FUBC. INTERPRETATION: Improved survival in hospitalized patients with GN-BSI who had FUBC is consistent with the results of recent publications from Italy and North Carolina supporting utilization of FUBC in management of GN-BSI. FUNDING: This study had no funding source.

Application of Standardized Antimicrobial Administration Ratio as a Motivational Tool within a Multi-Hospital Healthcare System.

The standardized antimicrobial administration ratio (SAAR) is a novel antimicrobial stewardship metric that compares actual to expected antimicrobial use (AU). This prospective cohort study examines the utility of SAAR reporting and inter-facility comparisons as a motivational tool to improve overall and broad-spectrum AU within a three-hospital healthcare system. Transparent inter-facility comparisons were deployed during system-wide antimicrobial stewardship meetings beginning in October 2017. Stakeholders were advised to interpret the results to foster competition and incorporate SAAR data into focused antimicrobial stewardship interventions. Student's t-test was used to compare mean SAARs in the pre- (July 2017 through October 2017) and post-intervention periods (November 2017 through June 2019). The mean pre-intervention SAARs for hospitals A, B, and C were 0.69, 1.09, and 0.60, respectively. Hospital B experienced significant reductions in SAAR for overall AU (from 1.09 to 0.83; p < 0.001), broad-spectrum antimicrobials used for hospital-onset infections (from 1.36 to 0.81; p < 0.001), and agents used for resistant gram-positive infections in the intensive care units (from 1.27 to 0.72; p < 0.001) after the interventions. The alignment of the SAAR across the health-system and sustained reduction in overall and broad-spectrum AU through implementation of inter-facility comparisons demonstrate the utility in the motivational application of this antimicrobial use metric.

Novel method of calculating adjusted antibiotic use by microbiological burden.

OBJECTIVE: To determine the usefulness of adjusting antibiotic use (AU) by prevalence of bacterial isolates as an alternative method for risk adjustment beyond hospital characteristics. DESIGN: Retrospective, observational, cross-sectional study. SETTING: Hospitals in the southeastern United States. METHODS: AU in days of therapy per 1,000 patient days and microbiologic data from 2015 and 2016 were collected from 26 hospitals. The prevalences of Pseudomonas aeruginosa, extended-spectrum ß-lactamase (ESBL)-producing bacteria, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE) were calculated and compared to the average prevalence of all hospitals in the network. This proportion was used to calculate the adjusted AU (a-AU) for various categories of antimicrobials. For example, a-AU of antipseudomonal ß-lactams (APBL) was the AU of APBL divided by (prevalence of P. aeruginosa at that hospital divided by the average prevalence of P. aeruginosa). Hospitals were categorized by bed size and ranked by AU and a-AU, and the rankings were compared. RESULTS: Most hospitals in 2015 and 2016, respectively, moved ≥2 positions in the ranking using a-AU of APBL (15 of 24, 63%; 22 of 26, 85%), carbapenems (14 of 23, 61%; 22 of 25; 88%), anti-MRSA agents (13 of 23, 57%; 18 of 26, 69%), and anti-VRE agents (18 of 24, 75%; 15 of 26, 58%). Use of a-AU resulted in a shift in quartile of hospital ranking for 50% of APBL agents, 57% of carbapenems, 35% of anti-MRSA agents, and 75% of anti-VRE agents in 2015 and 50% of APBL agents, 28% of carbapenems, 50% of anti-MRSA agents, and 58% of anti-VRE agents in 2016. CONCLUSIONS: The a-AU considerably changes how hospitals compare among each other within a network. Adjusting AU by microbiological burden allows for a more balanced comparison among hospitals with variable baseline rates of resistant bacteria.

Clostridioides difficile infection and antibiotic prescription rates in the community: Explaining the gender gap.

In this cross-sectional population-based study, women had significantly higher crude incidence rates of both community-associated Clostridioides difficile infection (CA-CDI) and ambulatory antibiotic prescriptions compared to men in South Carolina in 2015. After adjustments for antibiotic prescription rates, there was no difference in the incidence rates of CA-CDI between the genders.

Temporal trends in ambulatory antibiotic prescription rates in South Carolina: Impact of age, gender, and resident location.

OBJECTIVE: To examine the temporal trends in ambulatory antibiotic prescription fill rates and to determine the influences of age, gender, and location. DESIGN: Population-based cohort study. SETTING: Ambulatory setting in South Carolina. PATIENTS: Patients ≤64 years of age from January 2012 to December 2017. METHODS: Aggregated pharmacy claims data for oral antibiotic prescriptions were utilized to estimate community antibiotic prescription rates. Poisson regression or Student t tests were used to examine overall temporal trend in antibiotic prescription rates, seasonal variation, and the trends across age group, gender, and rural versus urban location. RESULTS: Overall antibiotic prescription rates decrease from 1,127 to 897 per 1,000 person years (P < .001). The decrease was more noticeable in persons aged <18 years (26%) and 18-39 years (20%) than in those aged 40-64 years (5%; P < .001 for all). Prescription rates were higher among females than males in all age groups, although this finding was the most pronounced in group aged 18-39 years (1,232 vs 585 per 1,000 person years; P < .0001). Annualized antibiotic prescription rates were higher during the winter months (December-March) than the rest of the year (1,145 vs 885 per 1,000 person years; P < .0001), and rates were higher in rural areas than in urban areas (1,032 vs 941 per 1,000 person years; P < .0001). CONCLUSIONS: The decline in ambulatory antibiotic prescription rates is encouraging. Ongoing ambulatory antibiotic stewardship efforts across South Carolina should focus on older adults, rural areas, and during the winter season when antibiotic prescriptions peak.

Pharmacist-Driven Culture and Sexually Transmitted Infection Testing Follow-Up Program in the Emergency Department.

Expanding pharmacist-driven antimicrobial stewardship efforts in the emergency department (ED) can improve antibiotic management for both admitted and discharged patients. We piloted a pharmacist-driven culture and rapid diagnostic technology (RDT) follow-up program in patients discharged from the ED. This was a single-center, pre- and post-implementation, cohort study examining the impact of a pharmacist-driven culture/RDT follow-up program in the ED. Adult patients discharged from the ED with subsequent positive cultures and/or RDT during the pre- (21 August 2018-18 November 2018) and post-implementation (19 November 2018-15 February 2019) periods were screened for inclusion. The primary endpoints were time from ED discharge to culture/RDT review and completion of follow-up. Secondary endpoints included antimicrobial agent prescribed during outpatient follow-up, repeat ED encounters within 30 days, and hospital admissions within 30 days. Baseline characteristics were analyzed using descriptive statistics. Time-to-event data were analyzed using the Wilcoxon signed-rank test. One-hundred-and-twenty-seven patients were included, 64 in the pre-implementation group and 63 in the post-implementation group. There was a 36.3% reduction in the meantime to culture/RDT data review in the post-implementation group (75.2 h vs. 47.9 h, p < 0.001). There was a significant reduction in fluoroquinolone prescribing in the post-implementation group (18.1% vs. 5.4%, p = 0.036). The proportion of patients who had a repeat ED encounter or hospital admission within 30 days was not significantly different between the pre- and post-implementation groups (15.6 vs. 19.1%, p = 0.78 and 9.4% vs. 7.9%, p = 1.0, respectively). Introduction of a pharmacist culture and RDT follow-up program in the ED reduced time to data review, time to outpatient intervention and outpatient follow-up of fluoroquinolone prescribing.

Direct Measurement of Performance: A New Era in Antimicrobial Stewardship.

For decades, the performance of antimicrobial stewardship programs (ASPs) has been measured by incidence rates of hospital-onset Clostridioides difficile and other infections due to multidrug-resistant bacteria. However, these represent indirect and nonspecific ASP metrics. They are often confounded by factors beyond an ASP's control, such as changes in diagnostic testing methods or algorithms and the potential of patient-to-patient transmission. Whereas these metrics remain useful for global assessment of healthcare systems, antimicrobial use represents a direct metric that separates the performance of an ASP from other safety and quality teams within an institution. The evolution of electronic medical records and healthcare informatics has made measurements of antimicrobial use a reality. The US Centers for Disease Control and Prevention's initiative for reporting antimicrobial use and standardized antimicrobial administration ratio in hospitals is highly welcomed. Ultimately, ASPs should be evaluated based on what they do best and what they can control, that is, antimicrobial use within their own institution. This narrative review critically appraises existing stewardship metrics and advocates for adopting antimicrobial use as the primary performance measure. It proposes novel formulas to adjust antimicrobial use based on quality of care and microbiological burden at each institution to allow for meaningful inter-network and inter-facility comparisons.