A Nanoporous 3D-Printed Scaffold for Local Antibiotic Delivery

Limitations of bone defect reconstruction include poor bone healing and osteointegration with acrylic cements, lack of strength with bone putty/paste, and poor osteointegration. Tissue engineering aims to bridge these gaps through the use of bioactive implants. However, there is often a risk of infection and biofilm formation associated with orthopedic implants, which may develop anti-microbial resistance. To promote bone repair while also locally delivering therapeutics, 3D-printed implants serve as a suitable alternative. Soft, nanoporous 3D-printed filaments made from a thermoplastic polyurethane and polyvinyl alcohol blend, LAY-FOMM and LAY-FELT, have shown promise for drug delivery and orthopedic applications. Here, we compare 3D printability and sustained antibiotic release kinetics from two types of commercial 3D-printed porous filaments suitable for bone tissue engineering applications. We found that both LAY-FOMM and LAY-FELT could be consistently printed into scaffolds for drug delivery. Further, the materials could sustainably release Tetracycline over 3 days, independent of material type and infill geometry. The drug-loaded materials did not show any cytotoxicity when cultured with primary human fibroblasts. We conclude that both LAY-FOMM and LAY-FELT 3D-printed scaffolds are suitable devices for local antibiotic delivery applications, and they may have potential applications to prophylactically reduce infections in orthopedic reconstruction surgery.

Clinical burden of invasive Escherichia coli disease among older adult patients treated in hospitals in the United States

BACKGROUND

Invasive extraintestinal pathogenic Escherichia coli disease (IED) can lead to severe outcomes, particularly among older adults. However, the clinical burden of IED in the U.S. has not been well characterized.

METHODS

IED encounters among patients ≥ 60 years old were identified using the PINC AI™ Healthcare Database (10/01/2015-03/31/2020) by either a positive E. coli culture in blood or another normally sterile body site and ≥ 1 sign of systemic inflammatory response syndrome or signs of sepsis, or a positive E. coli culture in urine with urinary tract infection and signs of sepsis. Medical resource utilization, clinical outcomes, and E. coli isolate characteristics were descriptively reported during the first IED encounter and during the following year (observation period).

RESULTS

Overall, 19,773 patients with IED were included (mean age: 76.8 years; 67.4% female; 78.5% with signs of sepsis). Most encounters involved community-onset IED (94.3%) and required hospitalization (96.5%; mean duration: 6.9 days), with 32.4% of patients being admitted to the intensive care unit (mean duration: 3.7 days). Most E. coli isolates were resistant to ≥ 1 antibiotic category (61.7%) and 34.4% were resistant to ≥ 3 antibiotic categories. Following their first IED encounter, 34.8% of patients were transferred to a skilled nursing/intermediate care facility, whereas 6.8% had died. During the observation period, 36.8% of patients were rehospitalized, 2.4% had IED recurrence, and in-hospital death increased to 10.9%.

CONCLUSIONS

IED is associated with substantial clinical burden at first encounter with considerable long-term consequences. Findings demonstrate the need for increased IED awareness and highlight potential benefits of prevention.

Economic burden of invasive Escherichia coli disease among older adult patients treated in hospitals in the United States

BACKGROUND: Although invasive Escherichia coli disease (IED) can lead to severe clinical outcomes, little is known about the associated medical resource use and cost burden of IED in US hospitals. OBJECTIVE: To comprehensively describe medical resource use and costs associated with IED during the initial IED event and over the subsequent 12 months. METHODS: Patients aged 60 years or older with 1 or more IED encounters were identified from the PINC AI Healthcare US hospital database (October 1, 2015, to March 31, 2020). The index encounter was defined as the first encounter with a positive E coli culture in a normally sterile site (group 1 IED) or positive E coli culture in urine with signs of sepsis (group 2 IED). Encounters with a positive culture from other bacteria or fungal pathogens were excluded. Outcomes were descriptively reported between admission and discharge for the index encounter and more than 1 - year post-index discharge. Medical resource use and costs included inpatient admissions and outpatient hospital services; costs were reported from a hospital's perspective (ie, charged amount) in 2021 USD. RESULTS: A total of 19,773 patients were identified (group 1 IED = 51.8%; group 2 IED = 48.2%). Mean age was 76.8 years, 67.4% were female, and 82.1% were White. Most index encounters were community-onset (94.3%) and led to hospitalization (96.5%) (mean inpatient days = 6.9 days). During the 1 - year post-index, 36.8% of patients had 1 or more all-cause hospitalizations. Mean [median] total all-cause hospital costs (as captured through the PINC AI Healthcare database) amounted to $16,760 [$11,340] during the index encounter and $10,942 [$804] during the 1 - year post-index; these costs were higher in the presence of sepsis and multidrug resistance and among hospital-onset IED. CONCLUSIONS: IED is associated with a substantial medical resource use and economic burden both during the initial encounter and over the following year in older adults. This highlights the critical need and potential benefits of preventive measures that may reduce the incidence of IED and associated economic burden. DISCLOSURES: This study was funded by Janssen Global Services, LLC. Dr Hernandez-Pastor is an employee of Janssen Pharmaceutica NV. Dr Geurtsen is an employee of Janssen Vaccines & Prevention BV. Dr Baugh is an employee of Janssen Research & Development, LLC. Dr El Khoury is an employee of Janssen Global Services, LLC. Dr Kalu and Dr Krishnarajah are employees of Janssen Scientific Affairs, LLC. Dr Gauthier-Loiselle, Ms Bungay, and Mr Cloutier are employees of Analysis Group, Inc., a consulting company that provided paid consulting services to Janssen Global Services, LLC. Dr Saade received consultation and speaker fees from Janssen.

411. Characterization of Antibiotic Prophylaxis Prior to Trans Rectal Ultrasound Guided Prostate Needle Biopsy (TRUS PNB): A 5-Year Nationwide Study among Patients in the United States Veterans Health Administration

Background

Prophylactic antibiotics are used prior to TRUS PNB to reduce risk for infectious complications such as UTI, prostatitis, epididymitis, orchitis, bacteremia and sepsis. Fluoroquinolones have been commonly used for prophylaxis, however, the incidence of post TRUS PNB infections caused by fluoroquinolone resistant Escherichia coli has increased. The purpose of this study was to characterize the prophylaxis agents used nationwide in the Veterans Health Administration (VHA) prior to TRUS PNB.

Methods

We conducted a review of records of all patients undergoing TRUS PNB in the VHA database from January 1st, 2013 to December 31st, 2018. We collected data about outpatient oral prophylaxis antibiotics, inpatient injectable antibiotics and microbiology results from rectal swabs and urine cultures performed within 90 days prior to the procedure.

Results

Of 153,055 patients undergoing prostate biopsy between January 1st, 2013 and December 31st, 2018, 27.6% (n=42,319) had urine cultures and 3.9% (n=5,294) had rectal swab cultures done within the 90-day window prior to the procedure. Among these who had urine and rectal swabs culture, 3.0% (n=1,292) and 20.1% (n=1,062) were positive for E. coli, respectively; 40.2% of E. coli isolates recovered from urine and 89.6% recovered from rectal swabs were resistant to fluoroquinolones. Table 1 shows the frequencies and percentages of oral prophylactic agents administered within the 90 days prior to the procedure and injectable antibiotics administered on the day of the procedure.

Frequency and percentage of oral prophylactic agents administered within the 90 days prior to the procedure and injectable antibiotics administered on the day of the procedure

Frequency and percentage of oral prophylactic agents administered within the 90 days prior to the procedure and injectable antibiotics administered on the day of the procedure

Conclusion

Despite the high rate of recovery of fluoroquinolone-resistant E. coli in pre-procedure urine and rectal swabs, oral fluoroquinolones remained the most frequently used prophylactic agents prior to TRUS PNB. This inadequate prophylactic coverage may increase the risk of infectious complications following prostate biopsy.

Disclosures

Elie Saade, MD, MPH, FIDSA, Janssen: Advisor/Consultant.

790. Can Electronic Clinical Decision Support Systems Improve the Diagnosis of Urinary Tract Infections?: A Systematic Review and Meta-Analysis

Background

Urinary tract infection (UTI) is a commonly misdiagnosed infectious condition. Stewardship interventions which successfully reduce rates of asymptomatic bacteriuria treatment (ASB) are often labor intensive, and thus a systematic solution is desirable. In this study, our objective was to systematically review studies to evaluate the effect of implementing a clinical decision support system on the ordering of urine culture tests for the diagnosis of UTI across diverse clinical settings.

Methods

We conducted a comprehensive electronic search of 5 databases and manual reference list review for peer-reviewed articles published prior to July 2, 2021. Studies which described an intervention designed to reduce unnecessary or incorrect diagnosis of UTI through utilization of CDS were included. The primary outcome of interest was rate of urine culture tests ordered. Two investigators independently screened studies and extracted and compiled data.

Results

A total of 5,013 studies were screened, of which 14 met inclusion criteria for the systematic review (Table 1). The most common intervention was urinalysis with reflex to urine culture based on pre-specified urinalysis parameters, such as a threshold level of pyuria. All 9 studies with statistical comparisons reported a decreased urine culture rate post-intervention, 8 of which were statistically significant (Table 2). Overall, a 37% decrease in urine culture rate was detected after CDS implementation (Table 3). Several studies also reported improvements in antimicrobial-related measures such as days of therapy and guideline-concordant therapy. Catheter-associated urinary tract infection rate was decreased in 2 studies and unchanged in 1 study. A limited number of included studies reported no adverse outcomes including increased bloodstream infection and mortality rates.

Conclusion

Electronic clinical decision support systems appear to be effective in decreasing unnecessary urine culture tests and improving UTI diagnosis. Prospective studies are needed to evaluate the impact on antimicrobial prescribing, patient-relevant outcomes, and potential adverse effects.

Disclosures

Elie Saade, MD, MPH, Janssen: Advisor/Consultant Curtis Donskey, MD, Pfizer, Clorox, Ecolab, and Professional Disposables International: Grant/Research Support Abhishek Deshpande, MD, PhD, Clorox: Grant/Research Support|Merck & Co., Inc., Kenilworth, NJ, USA: Advisor/Consultant|Merck & Co., Inc., Kenilworth, NJ, USA: Stocks/Bonds|Seres Therapeutics: Grant/Research Support.

1820. Clinical Characteristics of Invasive Extraintestinal Pathogenic Escherichia coli Disease Among Older Adult Patients Treated in Hospitals in the United States

Background

The risk of invasive extraintestinal pathogenic Escherichia coli disease (IED) increases with age and can lead to severe outcomes, including sepsis and death.

Aim

To describe the clinical outcomes of IED in older adults in the United States (US).

Methods

The Premier Healthcare Database (10/01/2015-03/31/2020) was used to identify IED encounters among patients ≥ 60 years old. The index encounter was defined as the first encounter with a positive E. coli culture in a normally sterile body site (Group 1) or a positive E. coli culture in urine with signs of sepsis (Group 2), in the absence of other pathogens. Outcomes included medical resource utilization, antibiotic use, IED recurrence, and in-hospital death, and were descriptively reported during the index encounter and over the subsequent year.

Results

Overall, 19,773 patients with IED were included (mean age: 76.8 years; 67.4% female; 82.1% white). Approximately half of index encounters were from Group 1 (51.8%), and the vast majority of patients had community-onset IED (94.3%). Most index encounters led to inpatient hospitalization (96.5%; mean duration: 6.9 days) and 32.4% required transfer to an intensive care unit (mean duration: 3.7 days). During the index encounter, patients received a mean [SD] of 2.9 [1.4] antibiotic agents, and 30.1% received ≥ 4 agents. The 3 most prevalent antibiotics received were ceftriaxone (66.2%), vancomycin (36.3%), and piperacillin (35.0%; Fig 1). The majority of E. coli isolates showed resistance to ≥ 1 antibiotic category (61.7%), and 34.4% were classified as multi-drug resistant (i.e., ≥ 3 categories). Following discharge, 34.8% of patients were transferred to a skilled nursing/intermediate care facility. In-hospital death reached 6.8% during the index encounter and increased to 10.9% 1-year post-index (Fig 2). One-year post-index, 2.4% of patients had an IED recurrence and 36.8% were readmitted to the hospital for any reason (Fig 3).

Conclusion

Our findings suggest that IED is a severe disease that is associated with substantial burden and far-reaching consequences beyond the initial encounter. These findings emphasize the need for increased awareness and surveillance of IED and its consequences and the potential benefit of preventative measures.

Disclosures

Elie Saade, MD, Janssen: Grant/Research Support|Pfizer: Board Member|Pfizer: Grant/Research Support|Sanofi Pasteur: Grant/Research Support|Sanofi Pasteur: Speaking/lecture fees, travel reimbursement|Seqirus: Grant/Research Support Jeroen Geurtsen, PhD, Janssen: Employee of Janssen Vaccines & Prevention BV Bryan Baugh, MD, Janssen Research & Development LLC: Employee|Janssen Research & Development LLC: Stocks/Bonds Antoine El Khoury, PhD, Janssen: Employee of Janssen Global Services, LLC. Nnanya Kalu, PhD, Janssen: Employee of Janssen Scientific Affairs, LLC. Marjolaine Gauthier-Loiselle, PhD, Janssen: Advisor/Consultant|Janssen: Advisor/Consultant Rebecca Bungay, MScPH, Janssen: Employees of Analysis Group, Inc. which has received consultancy fees from Janssen Scientific Affairs, LLC for the conduct of this studies. Martin Cloutier, MSc, Janssen: Employees of Analysis Group, Inc. which has received consultancy fees from Janssen Scientific Affairs, LLC for the conduct of this studies. Luis Hernandez Pastor, PharmD, PhD, Janssen: Employee of Janssen Pharmaceutica NV.

Clinical Impact of Ceftriaxone Resistance in Escherichia coli Bloodstream Infections: A Multicenter Prospective Cohort Study

Background

Ceftriaxone-resistant (CRO-R) Escherichia coli bloodstream infections (BSIs) are common.

Methods

This is a prospective cohort of patients with E coli BSI at 14 United States hospitals between November 2020 and April 2021. For each patient with a CRO-R E coli BSI enrolled, the next consecutive patient with a ceftriaxone-susceptible (CRO-S) E coli BSI was included. Primary outcome was desirability of outcome ranking (DOOR) at day 30, with 50% probability of worse outcomes in the CRO-R group as the null hypothesis. Inverse probability weighting (IPW) was used to reduce confounding.

Results

Notable differences between patients infected with CRO-R and CRO-S E coli BSI included the proportion with Pitt bacteremia score ≥4 (23% vs 15%, P = .079) and the median time to active antibiotic therapy (12 hours [interquartile range {IQR}, 1-35 hours] vs 1 hour [IQR, 0-6 hours]; P < .001). Unadjusted DOOR analyses indicated a 58% probability (95% confidence interval [CI], 52%-63%) for a worse clinical outcome in CRO-R versus CRO-S BSI. In the IPW-adjusted cohort, no difference was observed (54% [95% CI, 47%-61%]). Secondary outcomes included unadjusted and adjusted differences in the proportion of 30-day mortality between CRO-R and CRO-S BSIs (-5.3% [95% CI, -10.3% to -.4%] and -1.8 [95% CI, -6.7% to 3.2%], respectively), postculture median length of stay (8 days [IQR, 5-13 days] vs 6 days [IQR, 4-9 days]; P < .001), and incident admission to a long-term care facility (22% vs 12%, P = .045).

Conclusions

Patients with CRO-R E coli BSI generally have poorer outcomes compared to patients infected with CRO-S E coli BSI, even after adjusting for important confounders.

SARS-CoV-2 Seroprevalence Among First Responders in Northeastern Ohio, 2020

Objectives:

First responders, including firefighters, emergency medical technicians (EMTs), paramedics, and law enforcement officers, are working on the front lines to fight the COVID-19 pandemic and facing an increased risk of infection. This study assessed the seroprevalence of SARS-CoV-2 infection among first responders in northeastern Ohio.

Methods:

A survey and immunoglobulin G antibody test against SARS-CoV-2 nucleocapsid protein were offered to University Hospitals Health System–affiliated first-responder departments during May to September 2020. The survey contained questions about demographic characteristics and history of SARS-CoV-2 infection. A total of 3080 first responders with diverse job assignments from more than 400 fire and police departments participated in the study.

Results:

Of 3080 participants, 73 (2.4%) were seropositive and 26 (0.8%) had previously positive real-time polymerase chain reaction results. Asymptomatic infection accounted for 46.6% (34 of 73) of seropositivity. By occupation, rates of seropositivity were highest among administration/support staff (3.8%), followed by paramedics (3.0%), EMTs (2.6%), firefighters (2.2%), and law enforcement officers (0.8%). Work-associated exposure rates to COVID-19 patients were: paramedics (48.2%), firefighters (37.1%), EMTs (32.3%), law enforcement officers (7.7%), and administration/support staff (4.4%). Self-reported community exposure was positively correlated with self-reported work-associated exposure rate (correlation coefficient = 0.99). Neither self-reported community nor work-associated exposure was correlated with SARS-CoV-2 seroprevalence. We found no significant difference in seroprevalence among sex/gender or age groups; however, Black participants had a higher positivity rate than participants of other racial groups despite reporting lower exposure.

Conclusions:

Despite the high work-associated exposure rate to SARS-CoV-2 infection, first responders with various roles demonstrated seroprevalence no higher than their administrative/supportive colleagues, which suggests infection control measures are effective in preventing work-related infection.

SARS-CoV-2 antibody profile of naturally infected and vaccinated individuals detected using qualitative, semi-quantitative and multiplex immunoassays

This study measured antibodies against different antigen targets in healthcare workers (HCW) who have been fully vaccinated with mRNA vaccines, recovered from natural infection, or patients during active infection. All vaccinated individuals were positive for anti-RBD, anti-S1, and anti-S2 antibodies. The nonvaccinated recovered cohort showed 90% seropositivity by Atellica total antibody, 73% by Atellica IgG, 84% by Bioplex anti-RBD, 77% by Bioplex anti-S1, 37% by Bioplex anti-S2, and 79% by Bioplex antinucleocapsid respectively. The active infection cohort exhibited a similar pattern as the recovered cohort. About 88% and 78% of the recovered and active infection cohort produced both anti-spike and anti-N antibodies with Anti-S1/anti-N ratios ranging from 0.07 to 16.26. In summary, fully vaccinated individuals demonstrated an average of 50-fold higher antibody levels than naturally infected unvaccinated individuals with immune reactivity strongly towards RBD/S1 and a weak response to S2. The results support vaccination regardless of previous COVID-infection status.

Major adverse cardiovascular event definitions used in observational analysis of administrative databases: a systematic review

Background

Major adverse cardiovascular events (MACE) are increasingly used as composite outcomes in randomized controlled trials (RCTs) and observational studies. However, it is unclear how observational studies most commonly define MACE in the literature when using administrative data.

Methods

We identified peer-reviewed articles published in MEDLINE and EMBASE between January 1, 2010 to October 9, 2020. Studies utilizing administrative data to assess the MACE composite outcome using International Classification of Diseases 9th or 10th Revision diagnosis codes were included. Reviews, abstracts, and studies not providing outcome code definitions were excluded. Data extracted included data source, timeframe, MACE components, code definitions, code positions, and outcome validation.

Results

A total of 920 articles were screened, 412 were retained for full-text review, and 58 were included. Only 8.6% (n = 5/58) matched the traditional three-point MACE RCT definition of acute myocardial infarction (AMI), stroke, or cardiovascular death. None matched four-point (+unstable angina) or five-point MACE (+unstable angina and heart failure). The most common MACE components were: AMI and stroke, 15.5% (n = 9/58); AMI, stroke, and all-cause death, 13.8% (n = 8/58); and AMI, stroke and cardiovascular death 8.6% (n = 5/58). Further, 67% (n = 39/58) did not validate outcomes or cite validation studies. Additionally, 70.7% (n = 41/58) did not report code positions of endpoints, 20.7% (n = 12/58) used the primary position, and 8.6% (n = 5/58) used any position.

Conclusions

Components of MACE endpoints and diagnostic codes used varied widely across observational studies. Variability in the MACE definitions used and information reported across observational studies prohibit the comparison, replication, and aggregation of findings. Studies should transparently report the administrative codes used and code positions, as well as utilize validated outcome definitions when possible.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01440-5.

The Desirability of Outcome Ranking for the Management of Antimicrobial Therapy (DOOR MAT) Reveals Improvements in the Treatment of Bloodstream Infection Caused by Escherichia coli and Klebsiella pneumoniae in Patients from the Veterans Health Administration

BACKGROUND

Reductions in the use of broad-spectrum antibiotics is a cornerstone of antimicrobial stewardship. We aim to demonstrate the use of Desirability of Outcome Ranking Approach for the Management of Antimicrobial Therapy (DOOR MAT) to evaluate the treatment of Escherichia coli and Klebsiella pneumoniae bloodstream infection in patients from the Veterans Health Administration (VHA) across a decade.

METHODS

Using electronic records, we determined empiric and definitive antibiotic treatments, clinical characteristics and 30-day mortality of subjects with monomicrobial E. coli and K. pneumoniae bloodstream infection hospitalized in VHA medical centers from 2009 to 2018. Focusing on patients treated with parenteral β-lactams and with available antibiotic susceptibility testing results, we applied a range of DOOR MAT scores that reflect the desirability of antibiotic choices according to spectrum and activity against individual isolates. We report trends in resistance and desirability of empiric and definitive antibiotic treatments.

RESULTS

During the 10-year period analyzed, resistance to expanded-spectrum cephalosporins and fluoroquinolones increased in E. coli but not in K. pneumoniae, while resistance remained unchanged to carbapenems and piperacillin-tazobactam. In 6,451 cases analyzed, we observed improvements in DOOR MAT scores consistent with de-escalation. Improvement in desirability of definitive treatment compared to empiric treatment occurred in 26% of cases, increasing from 16% in 2009 to 34% in 2018. Reductions in overtreatment were sustained and without negative impact on survival.

CONCLUSION

DOOR MAT provides a framework to assess antibiotic treatment of E. coli and K. pneumoniae bloodstream infection and can be a useful metric in antimicrobial stewardship.

Adjuvanted influenza vaccine and influenza outbreaks in U.S. nursing homes: Results from a pragmatic cluster-randomized clinical trial

BACKGROUND

Influenza outbreaks in nursing homes pose a threat to frail residents and occur even in vaccinated populations. We conducted a pragmatic cluster-randomized trial comparing adjuvanted trivalent influenza vaccine (aTIV) versus trivalent influenza vaccine (TIV). Here, we report an exploratory analysis to compare the effect of aTIV versus TIV on facility-reported influenza outbreaks.

METHODS

Nursing homes were randomized to offer older residents either aTIV or TIV for the 2016-17 influenza season. The impact of the intent-to-treat vaccine assignment was evaluated for the total number of outbreaks reported from November-March. We collected data according to standard CDC definitions for both suspected outbreaks and those with a laboratory-confirmed case in nursing homes, and adjusted for facility-level vaccination rates and resident characteristics.

RESULTS

Of 823 randomized nursing homes, 777 (aTIV, n=387; TIV, n=390) reported information on influenza outbreaks. The treatment groups had similar characteristics at baseline except for race/ethnicity: homes assigned to TIV had a higher percentage of African-American residents (18.0% versus 13.7%). There were 133 versus 162 facility-reported suspected influenza outbreaks in aTIV versus TIV facilities respectively, of these 115 versus 140 were laboratory confirmed. The aTIV group experienced a 17% reduction in suspected (rate ratio, RR, 0.83, 95% confidence interval, CI: 0.65, 1.05) and laboratory-confirmed influenza outbreaks (RR 0.83, 95%CI: 0.63, 1.06). Covariate adjustment increased the estimated reduction for suspected outbreaks to 21% (RR 0.79, 95%CI: 0.61, 0.99) and 22% for laboratory confirmed (RR 0.78, 95%CI: 0.60, 1.02).

CONCLUSIONS

In an exploratory analysis of a cluster-RCT we observed 17-21% fewer outbreaks with aTIV than TIV.ClinicalTrials.gov number, NCT02882100.

LB-19. Association between contract staffing and reported outbreaks of SARS-CoV-2 in a cluster-randomized trial of 965 U.S. nursing homes

Background

Nursing home residents account for 45% SARS-CoV-2 related deaths in the U.S. but only 0.6% of the population. Our research group conducted a large pragmatic cluster randomized influenza vaccine trial in 965 nursing homes (NCT03965195). Due to the pandemic and its impact after the influenza season, we prospectively collected reports of SARS-CoV-2 outbreaks and performed a prospective study on the association between contract staffing and reported outbreaks of SARS-CoV-2. We hypothesized those using more contract nursing care would have higher risk of an outbreak.

Methods

From February through April, we collected monthly facility-level, self-reported data on SARS-CoV-2 outbreaks. Facility characteristics were taken from public data from Centers for Medicaid and Medicare services. Predictors of SARS-CoV-2 outbreaks were identified using a LASSO variable selection procedure, with a generalized linear, Poisson family model. Facility characteristics evaluated include demographics (e.g. number of residents), influenza vaccination rates, quality measures (e.g. % with UTI), and functional status (e.g. % with tube feedings). Facilities with contract staffing hours in the upper 25% quantile of direct care (RN, LPN, CNA) were considered ‘heavy use’.

Results

Of 965 randomized NHs, 663/965 (69%) reported data on SARS-CoV-2 outbreaks. On average, 13% of facilities had at least one outbreak, with 5/842 (0.5%) outbreaks in February, 91/835 (10.8%) in March and 217/686 (30%) in April. SARS-CoV-2 (+) facilities were larger (average total beds, 151 vs. 117), but were mostly similar by functional and cognitive status. Occupancy rate, total residents, Influenza vaccination rate, % with UTI, receiving respiratory treatments, tube feedings, and Medicaid payers were adjusted for in the analysis. The ‘heavy use’ of contract staffing included those with >223 hours per quarter. A multivariable regression found the relative risk SARS-CoV-2 outbreak was 1.56 (95% Confidence Interval: 1.22, 1.99) with heavy use of contract staffing.

Conclusion

The participating nursing homes in our vaccine trial with SARS-CoV-2 outbreaks were larger. Our study highlights that heavy use of contract staffing was associated with 56% increased risk of an outbreak.

Disclosures

Kevin McConeghy, Pharm.D., Pfizer (Grant/Research Support)Sanofi-Pasteur (Grant/Research Support)Seqirus Pharmaceuticals (Grant/Research Support) H. Edward Davidson, PharmD, MPH, Sanofi pasteur (Grant/Research Support, Scientific Research Study Investigator, Research Grant or Support)Seqirus (Grant/Research Support, Scientific Research Study Investigator, Research Grant or Support) Lisa Han, MPH, Sanofi Pasteur (Grant/Research Support)Seqirus (Grant/Research Support) David Canaday, M.D., Pfizer (Research Grant or Support)Sanofi Pasteur (Research Grant or Support)Seqirus (Advisor or Review Panel member, Research Grant or Support) Vincent Mor, Ph.D., naviHealth (Consultant)

Cluster-randomized trial of adjuvanted vs. non-adjuvanted trivalent influenza vaccine in 823 U.S. nursing homes

BACKGROUND

Influenza leads in preventable infection-related hospitalization in nursing home (NH) residents. The adjuvanted trivalent influenza vaccine (aTIV) is more immunogenic than similarly-dosed non-adjuvanted trivalent influenza vaccine (TIV) and observational studies suggest aTIV better prevents hospitalizations in older adults. We prospectively tested this in a NH setting.

METHODS

NHs with ≥ 50 long-stay residents ≥ 65 years were randomized to offer aTIV or TIV for residents for the 2016-17 influenza season. Using intent-to-treat resident-level analysis with Cox proportional hazards regression models adjusted for clustering by facility and a priori baseline covariates (e.g., age, heart failure, and facility-level characteristics), we assessed relative aTIV:TIV effectiveness for hospitalization [i.e., all-cause, respiratory, and pneumonia and influenza, (P&I)].

RESULTS

We randomized 823 NHs, housing 50,012 eligible residents, to aTIV or TIV. Residents were similar between groups by age (mean, ~79), heart failure, lung disease, and influenza and pneumococcal vaccine uptake, except aTIV homes housed fewer Black residents (14.5 vs. 18.9%). Staff vaccine uptake was similar (~55%). P&I and all-cause resident hospitalization rates were lower (adjusted HR 0.80, 95% CI: 0.66, 0.98, p=0.03; aHR 0.94, 95% CI: 0.89, 0.99, p=0.02, respectively) for aTIV vs TIV, while the respiratory hospitalization rate was similar, in a season where vaccine effectiveness was considered poor.

CONCLUSIONS

aTIV was more effective than TIV in preventing all-cause and P&I hospitalization from NHs during an A/H3N2 predominant season when TIV was relatively ineffective.Funded by Seqirus. ClinicalTrials.gov number, NCT02882100.

Characterization of Escherichia coli isolates potentially covered by ExPEC4V and ExPEC10V, that were collected from post-transrectal ultrasound-guided prostate needle biopsy invasive urinary tract and bloodstream infections

There is an increasing incidence of infectious complications caused by extraintestinal pathogenic Escherichia coli (ExPEC) after transrectal ultrasound-guided prostate needle biopsy (TRUS-PNB), and a need for prophylaxis methods effective against associated antibiotic-resistant organisms. We aimed to identify the O-serotypes of ExPEC isolates collected in a sample of 60 patients with invasive ExPEC disease (IED) after TRUS-PNB, by serotype-specific agglutination and polymerase chain reaction (PCR) assays. The prevalence of O-serotypes included in a tetravalent ExPEC vaccine was 38.3% by agglutination and 46.7% by PCR, while the prevalence of O-serotypes included in a decavalent vaccine was 58.3% and 73.3%, respectively. Therefore, compared to the tetravalent vaccine, the decavalent vaccine would theoretically provide coverage for serotypes carried by a higher proportion of circulating ExPEC in patients undergoing TRUS-PNB, including a high proportion of antibiotic-resistant organisms.

SARS-CoV-2 infection in a patient on chronic hydroxychloroquine therapy: Implications for prophylaxis

People exposed to COVID-19 have a risk of developing disease, and health care workers are at risk at a time when they are badly needed during a health care crisis. Hydroxychloroquine and chloroquine have been used as treatment and are being considered as prophylaxis. Our patient developed COVID-19 while on hydroxychloroquine and although more work is needed, this calls into question the role of these medications as preventive therapy.

557 Left ventricular diastolic function is a predictor of volumetric response to cardiac resynchronization therapy

Background

Conflicting data exist about the effects of cardiac resynchronization therapy (CRT) on diastolic function (DF). Aims of the study are: 1) to assess diastolic patterns in patients undergoing CRT; 2) to evaluate the role of DF in predicting CRT-response.

Methods

193 patients (age: 67 ± 11 ms, QRS width: 167 ± 21 ms, LVEF 28 ± 8%) were prospectively included in this multicentric study. 2D-standard echocardiography was performed before CRT and at 6-month follow-up (FU). DF was assessed according to recommendations from grade I to III. In case of data in the "grey zone", DF was defined as "indeterminate". A reduction of left ventricular (LV) end-systolic volume &gt;15% at FU identified CRT-responders (CRT-R).

Results

At 6-month FU, 132 patients (68%) were CRT-R. Figure 1 shows DF parameters in the overall population, CRT-R, and CRT-non responders (CRT-NR) before and after CRT. At multivariable analysis, grade I diastolic dysfunction at baseline was a significant independent predictor of CRT response (OR 3.02, p = 0.001) (Table 1). The addition of grade I diastolic dysfunction to a model including clinical (sex, NYHA class, ischemic cardiomyopathy) and echocardiographic parameters (LV size), significantly increase the model power for the prediction of CRT-response (χ2: 29 vs 44, p = 0.001).

Conclusions

Before CRT, DF parameters are significantly altered in CRT-NR with respect to CRT-R. Moreover, CRT-NR experience a significant deterioration of DF after CRT. In our population, grade I diastolic function at baseline was a significant independent predictor of positive response to CRT.

Table 1 Univariable analysis Multivariable analysis Age 1.01 (0.99-1.05) 0.25 Males 0.36 (0.17-0.76) 0.008 0.57 (0.22-1.47) 0.25 CAD 0.21 (0.11-0.40) &lt;0.001 0.31 (0.15-0.65) 0.002 NYHA 0.52 (0.31-0.88) 0.01 0.57 (0.22-1.47) 0.25 QRS 1.01 (0.99-1.02) 0.44 LVEDV 0.99 (0.99-1.00) 0.003 0.98 (0.97-1.01) 0.18 LVESV 0.99 (0.98-0.99) 0.005 1.01 (0.99-1.03) 0.28 LVEF 1.00 (0.97-1.05) 0.63 Grade I DD 4.13 (2.16-7.91) &lt;0.0001 3.02 (1.26-7.23) 0.001 Grade II DD 0.57 (0.40-0.80) 0.001 0.87 (0.35-2.19) 0.79 Grade III DD 0.76 (0.58-1.02) 0.06

Abstract 557 Figure.

Adjunctive Rifampin Therapy For Diabetic Foot Osteomyelitis in the Veterans Health Administration

IMPORTANCE

Among patients diagnosed with diabetes, the lifetime incidence of foot ulcers is 15%. Infection is a common complication of foot ulcers, and 20% to 60% of infections result in diabetic foot osteomyelitis (DFO). Current treatment guidelines do not endorse any specific antibiotic agent for DFO, but small clinical trials suggest the addition of rifampin to antimicrobial regimens results in improved cure rates for osteomyelitis.

OBJECTIVE

To compare the clinical outcomes of patients treated for DFO in the Veterans Health Administration (VHA) with and without adjunctive rifampin.

DESIGN, SETTING, AND PARTICIPANTS

This observational cohort study used VHA databases to identify index DFO cases from January 1, 2009, through December 31, 2013, and analyzed patients alive and without high-level amputation at 90 days after diagnosis in whom antibiotic therapy was initiated within 6 weeks of diagnosis. Patients with death or major amputation within 90 days of diagnosis, who were not treated with systemic antibiotics dispensed by the VHA within 6 weeks of diagnosis, or who were treated at facilities where rifampin was not dispensed for DFO were excluded. The retrospective cohort to inform the planning of a multisite randomized clinical trial was first investigated in spring 2015; retrospective analysis was performed from February 2017 through September 2019.

EXPOSURES

Patients initiating rifampin therapy within 6 weeks of the DFO diagnosis and receiving the drug for at least 14 days within 90 days of diagnosis were considered treated with rifampin. Patients not administered rifampin within 90 days of diagnosis served as the comparator group.

MAIN OUTCOMES AND MEASURES

A combined end point of mortality or amputation within 2 years of diagnosis was analyzed. Differences in times to event were evaluated using log-rank tests. Differences in event rates were compared using χ2 tests and multivariable logistic regression.

RESULTS

The analysis population included 130 patients treated with rifampin and 6044 treated without rifampin (total of 6174; 6085 men [98.6%]; mean [SD] age, 64.9 [9.7] years). Lower event rates were observed among the rifampin group (35 of 130 [26.9%] vs 2250 of 6044 [37.2%]; P = .02). Patients treated with rifampin were younger (mean [SD] age, 62.2 [9.4] vs 64.9 [9.6] years), had fewer comorbidities (mean [SD] Charlson comorbidity index score, 3.5 [1.8] vs 4.0 [2.2]), had more infectious disease specialty consultations (63 of 130 [48.5%] vs 1960 of 6044 [32.4%]), and more often had Staphylococcus aureus identified in cultures (55 of 130 [42.3%] vs 1755 of 6044 [29.0%]) than patients not treated with rifampin. A logistic regression estimating the odds of events and controlling for these and other covariates yielded a significant association of rifampin (odds ratio, 0.65; 95% CI, 0.43-0.96; P = .04).

CONCLUSIONS AND RELEVANCE

In this cohort study, patients administered rifampin experienced lower rates of death and amputation than patients not treated with rifampin, which remained significant after adjustment for confounders. These results coupled with existing evidence from small clinical trials suggest the addition of rifampin to current treatment regimens may be a useful antimicrobial option in the treatment of DFO.

Progressive and disseminated histoplasma infection and hemophagocytic lymphohistiocytosis in an immunocompetent adult

Hemophagocytic lymphohistiocytosis (HLH) in adults is a life-threatening underdiagnosed disorder that complicates different infectious syndromes and overlaps with sepsis. No guidelines are available for the management of HLH in adults. A high index of suspicion is required in patients with disseminated histoplasmosis.

2409. Drug-Induced Liver Injury (DILI) in a National Cohort of Hospitalized Patients Treated With Aztreonam and Ceftazidime

Background

DILI, although uncommon, can be a severe and even fatal complication of antibiotic use. The safety of novel regimens targeting MDR Gram-negative bacteria (GNB) is an important concern. Cephalosporins such as ceftazidime (CAZ) are rare causes of clinically apparent DILI, while data regarding DILI with other antibiotics such as the monobactam aztreonam (ATM) are sparse. ATM and CAZ are partnered with many novel β-lactamase inhibitors (i.e., avibactam, AVI) as therapy for MDR infections (CAZ-AVI and ATM-AVI) We aimed to compare the incidence and type of DILI associated with ATM and CAZ.

Methods

Using a cohort of patients hospitalized within Veterans Health Administration (VHA), we identified patients treated with ATM or CAZ for 3 or more consecutive days who also had LFTs measured during (day 3 or later) or within 7 days of stopping treatment. We excluded patients with abnormal LFTs in the year prior to ATM or CAZ treatment. Using alanine aminotransferase, alkaline phosphatase, and bilirubin measures, we applied clinical chemistry criteria to identify cases of DILI. We applied further criteria to classify DILI according to clinical pattern and severity (mild vs. moderate/severe), comparing the relative frequencies between ATM and CAZ.

Results

Among 18,813 courses of CAZ or ATM, 3,432 ATM and 2,662 CAZ courses met our criteria (Figure 1). While the overall rate of any DILI was higher in ATM than CAZ (5.8% vs. 3.2%, P < 0.01), the rate of moderate/severe DILI was similarly low for both agents (1.6% in ATM vs. 1.3% in CAZ, P = 0.3). The clinical pattern of DILI cases differed by drug, with the hepatocellular pattern comprising a larger proportion of the ATM DILI cases (37%) than the CAZ DILI cases (25%) and the cholestatic pattern comprising a smaller proportion (48% vs. 61%) (Figure 2).

Conclusion

In this national cohort of hospitalized patients treated with ATM or CAZ, the overall rate of DILI was significantly higher in patients treated with ATM than in those treated with CAZ. However, there is a similarly low rate of moderate/severe DILI. Although further analyses are required to better understand causal mechanisms and clinical risks of DILI in patients receiving ATM or CAZ, these data from a large national cohort provide a useful benchmark of drug safety.

Disclosures

T. Lodise, paratek: Consultant and Scientific Advisor, Consulting fee.

1953. Comparative Effectiveness of High- vs. Standard-Dose Influenza Vaccine on Hospitalization for Acute Myocardial Infarction in Nursing-Home Residents: A Post-hoc Analysis From a Large Cluster-Randomized Trial

Background

Methods

Results

Conclusion

Disclosures

1179. Incidence of Bacteremia and Bacteriuria With Antibiotic-Resistant Enterobacteriaceae After Transrectal Ultrasound-Guided Biopsy of the Prostate (TRUSBP)

Background

Infection with Escherichia coli after TRUSBP is common, but other Enterobacteriaceae also occur. In the absence of microbiological data, prophylaxis with co-trimoxazole (TMP-SMX) or fluoroquinolones (FQ) is usually prescribed. We estimated the incidence of bacteremia and bacteriuria after TRUSBP with distinct species of Enterobacteriaceae and their rate of resistance to common antibiotics.

Methods

Using Veterans Healthcare Administration (VHA) databases, we identified patients undergoing TRUSBP between January 1, 2013 and December 31, 2017. We determined the incidence of Enterobacteriaceae isolated from urine and blood cultures obtained within 30 days of TRUSBP. Using microbiology data from VHA, we determined rates of resistance to TMP-SMX, FQ (ciprofloxacin as marker), ESC (ceftriaxone as marker), and carbapenems (Carb) (ertapenem as marker).

Results

Overall, 377 (0.3%) and 1,739 (1.4%) of 126,761 TRUSBPs were complicated by bacteremia or bacteriuria with Enterobacteriaceae, respectively. E. coli was predominant (91% of blood and 81% in urine). Rates of FQ resistance were low in Klebsiellaand Enterobacter but exceeded 60% in E. coli. In general, TMP-SMX resistance exceeded 30%. Of note, 16.6% of blood and 11% of urine Enterobacteriacaea were resistant to ESC, while Carb-resistance was rare.

Conclusion

FQ and ESC-resistant Enterobacteriaceae are prevalent in bacteremia and bacteriuria after TRUSBP. Antibiotics used for prophylaxis and empirical treatment are likely to be ineffective. The prevention and management of TRUSBP-related infections should include microbiology-guided approaches.

Disclosures

All authors: No reported disclosures.

996. A Cluster-Randomized Trial of Adjuvanted Trivalent Influenza Vaccine vs. Standard Dose in US Nursing Homes

Background

Pneumonia and influenza lead as vaccine-preventable infections among nursing home (NH) residents. Immunosenescence reduces vaccine response and protection from infections. More immunogenic vaccines, e.g., adjuvanted trivalent influenza vaccine [aTIV], can improve clinical outcomes. We evaluated all-cause hospitalization among long-stay NH residents offered aTIV vs. trivalent influenza vaccine (TIV).

Methods

We randomized 823 NHs within 75 miles of a Centers for Disease Control and Prevention influenza reporting city to offer one of the two egg-based influenza vaccines, aTIV or TIV, as their 2016–2017 influenza season standard of care. For the subset of long-stay NH residents (&gt;100 days in facility as of October 1, 2016) aged ≥65 years, we determined how many were hospitalized from November 1, 2016 to June 1, 2017 on an intent-to-treat basis. We obtained all-cause hospitalization, patient-, and facility-level characteristics from Minimum Data Set and Certification and Survey Provider Enhanced Reporting data. Our primary outcome was time to first hospitalization, using Cox proportional hazards models.

Results

The analytic sample included 26,300 residents in 412 NHs randomized to offer aTIV and 26,474 in 410 NHs randomized to TIV. Mean age was 82.3 vs. 82.3 years, 69.3% vs. 68.6% were women, and 15.5% vs. 20.1% were African-American, for aTIV and TIV NHs, respectively. The number of residents vaccinated in the facility against influenza was 17,976 (68.3%) and 18,364 (69.4%), with an overall vaccination rate of 78.4% and 79% for aTIV and TIV NHs. Mean staff vaccination was 53.4% and 54.4% for aTIV and TIV NHs. There were 5,479 (20.8%) hospitalizations in the aTIV and 5,839 (22.1%) in TIV NHs, respectively [adjusted as prespecified, hazard ratio (HR) 0.94, 95% confidence interval (CI): 0.88, 0.99]. Post-hoc adjustment for the imbalance in race increased heterogeneity, HR 0.97, 95% CI: 0.91, 1.04. A total of 18.2% vs. 17.5% (HR 1.05, 95% CI: 0.99, 1.11) of residents in aTIV and TIV NHs died.

Conclusion

Compared with TIV, aTIV may reduce hospitalization risk of long-stay NH residents during a predominantly A/H3N2 influenza season, despite reported reduced effectiveness due to egg-based mutagenesis of egg-based vaccines.

NCT: 02882100

Disclosures

S. Gravenstein, Seqirus: Consultant, Grant Investigator and Scientific Advisor, Consulting fee, Research grant and Speaker honorarium. H. E. Davidson, Seqirus: Grant Investigator and Investigator, Research grant and Research support. K. Mcconeghy, Seqirus: Investigator, Research support. L. Han, Seqirus: Investigator and Research Contractor, Research grant. D. Canaday, Seqirus: Grant Investigator, Research grant and Research support. E. Saade, Seqirus: Investigator, Research grant and Research support. R. R. Baier, Seqirus: Investigator, Research support. V. Mor, Seqirus: Investigator, Research grant and Research support.

2397. Comparing Predictive Performance of INCREMENT Scores on Mortality Among Patients With Carbapenem-Non-Susceptible (CNS) Klebsiella pneumoniae (Kp) and Enterobacter cloacae Complex (Ecc) Bloodstream Infections (BSI) in the Veterans Health Administration (VHA)

Background

INCREMENT is an international collaborative study of BSI caused by extended-spectrum β-lactamase (ESBL) or carbapenemase-producing Enterobacteriaceae (CPE) that has developed and validated predictive models for mortality. Most CNS Enterobacteriaceae BSI in the VHA are either Klebsiella pneumoniae (Kp) or Enterobacter cloacae complex (Ecc). We applied the INCREMENT score for CPE to predict mortality in patients with CNS-Kp and CNS-Ecc BSIs in the VHA and compared the distribution and predictive performance of the score across organisms.

Methods

Using nationwide VHA databases, unique patients in the continental United States with Kp or Ecc BSI post 48 hours of hospitalization from 2006 to 2015 were identified. Isolates with intermediate susceptibility or resistance to any tested carbapenem were considered non-susceptible. We used databases and medical records to obtain clinical characteristics, treatment, and outcomes, and applied INCREMENT criteria and definitions to calculate a prediction score. We compared the distribution of the scores by organism and used receiver operating curve methods to compare predictive performance between Kp and Ecc BSI.

Results

We identified 57 patients with CNS-Ent and 140 with CNS-Kp BSI. The demographics and infection characteristics were highly consistent across organisms, both afflicting patients who were predominantly male, older and chronically ill. Mortality at 14 days was 39% in CNS-Ecc and 38% in CNS-Kp. Similar proportions (65% of Ecc and 68% of Kp) met the criteria for an INCREMENT score: monomicrobial and alive over 48 hours after culture specimen. The distribution of scores was similar within mortality outcomes across organisms, with the highest scores observed in Kp patients who died (Figure 1). The ROC areas under the curve were 0.71 for CNS-Ecc and 0.75 for CNS-Kp (Figure 2). A multivariable logistic model predicting mortality detected neither an organism effect nor an interaction of organism and INCREMENT score.

Conclusion

The INCREMENT score, validated in a CPE cohort predominantly comprised of Kp, performed similarly well across CNS-Ent and CNS-Kp patients in our cohort. This suggests the model is robust to CNS organisms of undetermined resistance mechanism and that the association between INCREMENT and mortality is consistent across Kp and Ecc.

Disclosures

All authors: No reported disclosures.

1483. Pleural Empyema Caused by Stenotrophomonas maltophilia in a National Cohort of Hospitalized Veterans

Background

S. maltophilia is an environmental multi-drug-resistant Gram-negative bacteria that is mostly found as a respiratory tract colonizer in patients with cystic fibrosis (CF) and as an opportunist in immunocompromised hosts. To understand the role of this pathogen in non-CF patients, we performed a retrospective analysis of hospitalized patients with S. maltophilia empyema in the Veterans Health Administration (VHA).

Methods

Using microbiology results within the VHA Corporate Data Warehouse, we identified pleural fluid cultures that tested positive for S. maltophilia among 1.9 million hospitalized patients between January 1, 2010 and December 31, 2017. We then reviewed the electronic health records for these patients and collected demographics, clinical characteristics, microbiology, antibiotic treatment, and outcome (30-day mortality).

Results

We identified 45 unique patients with S. maltophilia in pleural fluid cultures from 21 VHA facilities. Associated conditions included prolonged chest tube presence (n = 35), recent hospital admission (n = 34), recent antibiotic exposure (n = 30), cancer (n = 25), recent ICU stay (n = 23), and cardiothoracic surgery (n = 21). Most cultures were polymicrobial (n = 36), with the most commonly isolated organisms being Enterobacteriaceae (n = 12), Staphylococcus spp. (n = 11), and Pseudomonas aeruginosa (n = 9). According to susceptibility testing, trimethoprim-sulfamethoxazole (TMP-SMX) was the most active agent (93% susceptible), followed by levofloxacin (85%). Only 49% of tested isolates were susceptible to ceftazidime. In 27 (60%) of the cases, treatment directed against S. maltophilia was administered with TMP-SMX (n = 16), levofloxacin (n = 7) and minocycline (n = 4). In two cases, S. maltophilia was considered a contaminant since there was no evidence of pleural infection. In both groups, 30-day mortality was 22% (6/27 treated vs. 4/18 untreated).

Conclusion

S. maltophilia is infrequently isolated from pleural fluid among patients in the VHA system and is commonly a polymicrobial infection following instrumentation or surgery. In this cohort, we observed a high mortality independent of treatment, likely reflecting host co-morbidities or ineffective treatments.

Disclosures

All authors: No reported disclosures.

Therapies for multidrug resistant and extensively drug-resistant non-fermenting gram-negative bacteria causing nosocomial infections: a perilous journey toward 'molecularly targeted' therapy

INTRODUCTION

Non-fermenting Gram-negative bacilli are at the center of the antimicrobial resistance epidemic. Acinetobacter baumannii and Pseudomonas aeruginosa are both designated with a threat level to human health of 'serious' by the Centers for Disease Control and Prevention. Two other major non-fermenting Gram-negative bacilli, Stenotrophomonas maltophilia and Burkholderia cepacia complex, while not as prevalent, have devastating effects on vulnerable populations, such as those with cystic fibrosis, as well as immunosuppressed or hospitalized patients. Areas covered: In this review, we summarize the clinical impact, presentations, and mechanisms of resistance of these four major groups of non-fermenting Gram-negative bacilli. We also describe available and promising novel therapeutic options and strategies, particularly combination antibiotic strategies, with a focus on multidrug resistant variants. Expert commentary: We finally advocate for a therapeutic approach that incorporates in vitro antibiotic susceptibility testing with molecular and genotypic characterization of mechanisms of resistance, as well as pharmacokinetics and pharmacodynamics (PK/PD) parameters. The goal is to begin to formulate a precision medicine approach to antimicrobial therapy: a clinical-decision making model that integrates bacterial phenotype, genotype and patient's PK/PD to arrive at rationally-optimized combination antibiotic chemotherapy regimens tailored to individual clinical scenarios.

A 17-Year Nationwide Study of Burkholderia cepacia Complex Bloodstream Infections Among Patients in the United States Veterans Health Administration

Background

Burkholderia cepacia complex (Bcc) are a group of multidrug-resistant gram-negative bacteria rarely reported in patients without cystic fibrosis (CF) or immunocompromising conditions. We investigated Bcc bloodstream infections (BSIs) in a cohort of non-CF patients from the US Veterans Health Administration (VHA).

Methods

Using VHA databases, we identified patients with Bcc BSI at facilities nationwide from 1999 through 2015. We ascertained clinical characteristics, treatments, and outcomes and identified factors associated with 30-day mortality in logistic regression analysis.

Results

We identified 248 patients with Bcc BSI, who were of advanced age (mean, 68 years), chronically ill, and had severe disease. The most common sources were central venous catheters (41%) and pneumonia (20%). Most cases were hospital-acquired (155 [62%]) or healthcare-associated (70 [28%]). Mortality at 14, 30, and 90 days was 16%, 25%, and 36%, respectively. Trimethoprim-sulfamethoxazole (TMP-SMX) and fluoroquinolones were active against 94% and 88% of isolates, respectively. Susceptibility to ceftazidime and meropenem occurred in approximately 70% of the isolates. The most prescribed antibiotics were fluoroquinolones (35%), followed by carbapenems (20%), TMP-SMX (18.5%), and ceftazidime (11%). In regression analysis, age (OR, 1.06 [95% confidence interval {CI}, 1.02-1.10], per added year) and the Pitt bacteremia score (OR, 1.65 [95% CI, 1.44-1.94], per unit increase) were associated with higher 30-day mortality.

Conclusions

In this large cohort of BSIs caused by Bcc, cases were mostly hospital-acquired and we observed high mortality, significant resistance to ceftazidime, and limited use of TMP-SMX. These observations add to our understanding of Bcc infection in non-CF patients and highlight the need for interventions to improve their outcome.

The Use of Rifampin Therapy to Treat Diabetic Patients with Osteomyelitis of the Foot in the Veterans Health Administration: Patient Characteristics and Clinical Outcomes

Background

Nearly 25% of Veterans Health Administration (VHA) patients are diagnosed with diabetes mellitus (DM). Among DM patients, the lifetime incidence of foot ulcers is 15%. Infection is a common complication of foot ulcers and 20–60% of infections result in diabetic foot osteomyelitis (DFO). Current treatment guidelines do not endorse any specific antibiotic agent for DFO, but small clinical trials suggest the addition of rifampin to antimicrobial regimens results in improved cure rates for osteomyelitis.

Methods

Using VHA databases, we identified index DFO cases from 2009 to 2013 and extracted patient and infection characteristics including demographics, comorbidities, chronic medications, antibiotic regimens, and microbiology data when present. We analyzed the subset of patients alive, without high-level amputation, and treated with antibiotics at 90 days after diagnosis. We summarized patient characteristics and compared a composite endpoint of amputation or death within 2 years of DFO diagnosis among those treated with rifampin to those not treated with rifampin.

Results

In total, 10,736 DFO cases met our criteria (Figure). Of these, 151 were considered treated with rifampin, based on 14 or more days of rifampin initiated within 90 days of diagnosis; 10,551 were unexposed to rifampin; and 34 were excluded for late or short treatment with rifampin. We observed significant differences between patients treated with and without rifampin (Table) and 44% of rifampin-treated patients were seen in 14 facilities.

Amputation or death at 2 years was observed in 44 (29%) of patients treated with rifampin and 4,007 (38%) of patients not treated with rifampin (P = 0.03).

Conclusion

Rifampin was rarely used in the treatment of DFO in the VHA and a few facilities accounted for a large proportion of rifampin-treated cases. We observed higher rates of amputation-free survival in patients treated with rifampin, but in the presence of notable confounders including age, comorbidities, and organism.

Disclosures

E. Saade, Steris: Grant Investigator, Grant recipient. Janssen: Grant Investigator, Research grant. Sequiris: Grant Investigator, Research grant. Pfizer: Grant Investigator, Research grant. R. A. Bonomo, Entasis: Grant Investigator, Research grant. Allecra: Grant Investigator, Research grant. Wockhardt: Grant Investigator, Research grant. Merck: Grant Investigator, Research grant. Roche: Grant Investigator, Research grant. GSK: Grant Investigator, Research grant. Allergan: Grant Investigator, Research grant. Shionogi: Grant Investigator, Research grant

Carbapenem-Resistant Enterobacter cloacae in Patients from the US Veterans Health Administration, 2006-2015

We analyzed carbapenem-resistant Enterobacteriaceae (CRE) trends among patients from the US Veterans Health Administration (VHA). After the emergence of CRE in the eastern United States, resistance rates remained stable in Klebsiella pneumoniae but increased in Enterobacter cloacae complex, suggesting a "second epidemic". VHA offers a vantage point for monitoring nationwide CRE trends.

High Proportion of False-Positive Clostridium difficile Enzyme Immunoassays for Toxin A and B in Pediatric Patients

Objectives.

To determine the frequency of false-positive Clostridium difficile toxin enzyme immunoassay (EIA) results in hospitalized children and to examine potential reasons for this false positivity.

Design.

Nested case-control.

Setting.

Two tertiary care pediatric hospitals.

Methods.

As part of a natural history study, prospectively collected EIA-positive stools were cultured for toxigenic C. difficile, and characteristics of children with false-positive and true-positive EIA results were compared. EIA-positive/culture-negative samples were recultured after dilution and enrichment steps, were evaluated for presence of the tcdB gene by polymerase chain reaction (PCR), and were further cultured for Clostridium sordellii, a cause of false-positive EIA toxin assays.

Results.

Of 112 EIA-positive stools cultured, 72 grew toxigenic C. difficile and 40 did not, indicating a positive predictive value of 64% in this population. The estimated prevalence of C. difficile infection (CDI) in the study sites among children tested for this pathogen was 5%–7%. Children with false-positive EIA results were significantly younger than those with true-positive tests but did not differ in other characteristics. No false-positive specimens yielded C. difficile when cultured after enrichment or serial dilution, 1 specimen was positive for tcdB by PCR, and none grew C. sordellii.

Conclusions.

Approximately one-third of EIA tests used to evaluate pediatric inpatients for CDI were falsely positive. This finding was likely due to the low prevalence of CDI in pediatric hospitals, which diminishes the test's positive predictive value. These data raise concerns about the use of EIA assays to diagnosis CDI in children.

Infect Control Hosp Epidemiol 2012;33(2):175-179

Appropriateness of empiric therapy in patients with suspected Clostridium difficile infection

OBJECTIVE

The objective of this study was to test the hypothesis that many patients with suspected Clostridium difficile infection (CDI) receive inappropriate empiric therapy and/or receive continued therapy despite negative test results.

METHODS

We performed a 3 month prospective cohort study at the Cleveland Veteran Affairs Medical Center to assess the appropriateness of empiric CDI therapy for all patients with stool samples submitted for CDI testing. Empiric therapy for CDI was considered appropriate if patients with suspected CDI had findings suggestive of severe or complicated illness.

RESULTS

Of 251 patients tested for CDI, 53 (21%) received empiric treatment, including 45 (85%) treated with metronidazole and 8 (15%) treated with vancomycin. Of the 53 empirical therapy regimens, only 20 (38%) were deemed appropriate based on criteria for severe or severe, complicated CDI and 39 (74%) had negative laboratory testing for CDI. Twenty-one of 39 (54%) patients with negative testing were continued on therapy for three or more days despite the negative results. The key limitations of the study are the fact that it was conducted in a single institution and had a small sample size.

CONCLUSION

In our facility, empiric treatment for CDI was common and more than half of empirical treatment was deemed inappropriate because patients did not meet criteria for severe CDI. Because CDI therapy may be associated with adverse effects, there is a need for interventions to improve the appropriateness of empiric CDI treatment.

Specialty care delivery: bringing infectious disease expertise to the residents of a Veterans Affairs long-term care facility

OBJECTIVE

To initiate a long-term care facility (LTCF) infectious disease (LID) service that provides on-site consultations to LTCF residents to improve the care of residents with possible infections.

DESIGN

Clinical demonstration project.

SETTING

A 160-bed LTCF affiliated with a tertiary care Veterans Affairs (VA) hospital.

PARTICIPANTS

Residents referred to the LID team.

MEASUREMENTS

The reason for and source of LTCF residents' referral to the LID team and their demographic characteristics, infectious disease diagnoses, interventions, and hospitalizations were determined.

RESULTS

Between July 2009 and December 2010, the LID consultation service provided 291 consultations for 250 LTCF residents. Referrals came from LTCF staff (75%) or the VA hospital's ID consult service (25%). The most common diagnoses were Clostridium difficile infection (14%), asymptomatic bacteriuria (10%), and urinary tract infection (10%). More than half of referred residents were receiving antibiotic therapy when they first saw the LID team; 46% of residents required an intervention. The most common interventions, stopping (32%) or starting (26%) antibiotics, were made in accordance with principles of antibiotic stewardship.

CONCLUSION

The LID team represents a novel and effective means to bring subspecialty care to LTCF residents.

Patient-administered sphenopalatine ganglion block

BACKGROUND AND OBJECTIVES

Pain resulting from head and neck cancer can be severe and difficult to manage. Avoiding hospitalization for as long as possible with a reasonable level of comfort requires a number of therapeutic modalities. The usefulness of self-administered sphenopalatine ganglion block was evaluated in a patient with lethal midline granuloma requiring large doses of morphine.

METHODS

A 30-year-old woman with intractable pain from lethal midline granuloma was taught to self-administer 4% lidocaine, 1.5 mL topically into each nostril three times per day.

RESULTS

A 3-month follow-up examination showed substantial pain relief and reduction in morphine requirement. No adverse side effects or complications developed.

CONCLUSIONS

In certain patients, sphenopalatine ganglion block can be effectively self-administered at home to manage chronic pain.