bluuebunny/crossref_metadata_2025 huggingface dataset:
2146. MALDI-TOF Mass Spectrometry Rapid Pathogen Identification and Outcomes of Patients with Bloodstream Infection: A Systematic Review and Meta-analysis
Authors: Hsieh Ronan , Mekary Rania , Li Raymund , Lin Chi-Yang , Weng Tzu-Hua , Hsu Wan-Ting , Li Guilin , Chang Chia-Na , Li Huayin , Liu Xiaoying , Lee Chien-Chang
Published: October 2019

Background

Several studies showed inconsistent results on the efficiency measures of the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) technology and patients’ clinical outcomes. A meta-analysis was conducted to determine the effectiveness of MALDI-TOF MS-based bacteriology in improving the accuracy of microbiology report and clinical outcomes.

Methods

PubMed and EMBASE databases were searched from database inception through May 1, 2018 for pre–post and parallel comparative studies that evaluated the use of MALDI-TOF MS for identification of microorganism from blood culture. Pooled effect estimates were derived using the random-effects model. Univariate meta-regression on trial-level covariates was used to assess heterogeneity sources. Funnel plot, Begg’s and Egger’s tests were used to assess publication bias.

Results

Thirteen studies with 3,534 patients were meta-analyzed. Compared with conventional methods, MALDI-TOF MS was associated with 34% reduction in mortality (RR = 0.66; 95% CI: 0.54; 0.81; I2 = 27.6%; 9 studies); 5.3-hour reduction in time-to-effective antibiotic therapy (95% CI: -6.4; -4.3; I2 = 98.0%), 24.5-hour reduction in time to identify bacteria (95% CI: −25.7; −23.3; I2 = 91.0%); 0.9-day reduction in hospital stay (95% CI: −1.4; −0.3; I2 = 56.6%), and US$4100 saving in direct hospitalization cost (95% CI: $−8,200; $−113; I2 = 66.1%). No significant heterogeneity sources were found (all P-interaction from meta-regression > 0.05) and no statistical evidence for publication bias was found (all P > 0.05).

Conclusion

Rapid pathogen identification by MALDI-TOF MS with or without antibiotic stewardship was associated with reduced mortality, improved outcomes of bloodstream infection, and may be cost-effective among patients with bloodstream infection. Nevertheless, a multicenter randomized controlled trial is needed to confirm findings of these pre–post comparison studies.

Disclosures

All authors: No reported disclosures.
2153. Clinical Impact of Addition of Oropharynx MRSA PCR to Anterior Nares MRSA PCR for Patients Admitted with Pneumonia
Authors: Kessler Michael , Biswas Sandip , Choera Tsokyi , Chen Derrick , Lepak Alexander , Lepak Alexander
Published: October 2019

Background

Anterior nares (AN) MRSA PCR can help identify MRSA colonization as a risk factor for MRSA pneumonia and can be especially useful, given high NPV, in making treatment decisions when lower respiratory tract (LRT) cultures are lacking. Oropharynx (OP) MRSA carriage without AN colonization can occur suggesting the potential benefit of duel site screening, but doubles resource utilization. We evaluated concordance between the AN and OP sites and whether the addition of OP MRSA PCR testing provides clinical benefit.

Methods

MRSA PCR was performed using Xpert SA Nasal Complete (Cepheid; FDA-cleared and modified). Results were retrieved from January 2017 to July 2018 for adult in-patients who received both AN and OP testing within the same calendar day. Medical charts were reviewed for a clinical course, respiratory culture results, and effect of discordant PCR results.

Results

AN and OP MRSA PCRs were performed on 1,419 adult inpatients, concordance was 96.5% (n = 1370, see Table). In 38 of 49 discordant cases, PCR was used to evaluate the etiology of pneumonia. Of those, 22 (58%) had LRT culture results available within 48 h to direct therapy. We further evaluated the value of OP PCR by focusing on AN-/OP+ (n = 22) discordant results, of which 16 were used to evaluate pneumonia. LRT culture results were available in 7 (44%) of these cases. Three had isolation of MRSA; however, the remaining 4 were culture-negative but still received vancomycin for an average of 5 days. Of the 9 that were AN−, OP+, and without culture results, only 4 had clinical signs and symptoms consistent with MRSA pneumonia. OP MRSA PCR is $303.

Conclusion

OP and AN MRSA PCR screening are highly concordant in patients with pneumonia. 355 AN/OP PCRs (4/1419), at > $100,000 in additional healthcare costs, were needed to detect one potentially missed MRSA pneumonia compared with AN PCR only approach. Our results suggest addition of OP MRSA PCR: (1) has limited clinical utility for pneumonia evaluation as it is unlikely to be discordant with AN testing, which will not significantly alter the very high NPV and when discordant (AN-/OP+) has a <50% PPV, (2) is unlikely to be cost-effective, and (3) has unintended consequences such as overuse of MRSA therapy. Additionally, there is an opportunity to improve PCR ordering to include only those situations in which LRT cultures are lacking.

Disclosures

Alexander Lepak, MD, Paratek Pharmaceuticals: Research Grant; Tetraphase Pharmaceuticals: Research Grant.
2163. Clinical Impact of Inter-site Blood Culture Transport in a Canadian Tertiary Care Center
Authors: Carignan Alex , Dufour Kevin , Beauregard-Paultre Catherine , Martin Philippe
Published: October 2019

Background

The potential delays caused by transport of blood cultures to server laboratories might result in delayed issuance of results for patients with positive blood cultures. In this study, we aimed to determine the clinical impacts of inter-site transport of blood cultures.

Methods

We performed a retrospective cohort study involving cases with positive blood cultures (1 positive blood culture/species/patient/7 days; not deemed as a contaminant) at two sites of a Canadian tertiary care center between January 1, 2018 and December 31, 2018. Blood cultures from the affiliated site were transported to the laboratory of the primary server site. These two sites are located 8 km apart. The following outcomes were studied: the duration between blood culture sampling and issuance of the first report and the duration between blood culture sampling and administration of the first effective antibiotic.

Results

We observed 349 episodes of bacteremia, including 161 in the affiliated site (45.5%) and 193 in the primary server center (54.5%). Enterobacteriaceae (n = 151, 43%) and Staphylococcus aureus (n = 77, 22%) were the most commonly observed causative bacteria. Median duration for issuance of the first positive report was significantly shorter in the primary server hospital (32.4 h, interquartile range [IQR] 19.8–44.3) than in the affiliated center (37.9 h, IQR 24.1–46.5; P = 0.004). The median duration between blood culture sampling and administration of the first effective antibiotic was 2.7 h in the server site (IQR 0.75–15.2) and 2.3 h in the affiliated site (IQR 1–8.45) (P = 1.0). Receiving the first effective antibiotic after blood culture sampling required > 60 min in 8/189 patients (4.2%) in the affiliated site and 9/158 patients (5.7%) in the primary server site (P = 0.3). The 30-day mortality was 13.8% (26/189) and 8.9% (14/158) at the primary server site and affiliated site, respectively (P = 0.16).

Conclusion

Inter-site transport of blood cultures is associated with a significant delay in the issuance of positive blood culture reports. However, this delay does not cause any delay in administration of effective antibiotic therapy because of rapid recognition of sepsis in bacteremia patients. These results are reassuring in the context of increasing microbiology service centralization.

Disclosures

All authors: No reported disclosures.
2171. Phenotypic Correlations for the Presence of CTX-M in Enterobacteriaceae and mecA in Staphylococcus aureus using the Verigene® Blood Culture System
Authors: Masayuki Nigo , Wanger Audrey , Arias Cesar A
Published: October 2019

Background

Rapid identification of antimicrobial resistance markers has the potential to help targeting antimicrobial therapy and enhance efforts for antibiotic stewardship. However, limited data are available to correlate phenotypic and genotypic results for some of these platforms in positive blood cultures (BC). Here, we aimed to evaluate the ability of the Verigene® (VG) Blood Culture System to predict phenotypic susceptibility patterns with the detection of the genes encoding the CTX-M in Enterobacteriaceae and MecA in S. aureus (SA) in a large dataset.

Methods

Phenotypic susceptibility and VG results were retrospectively collected between August 2017 and December 2018 from 12 hospitals in Houston, TX. VG testing was performed on only the first isolate was considered in persistent positive BCs. The VG report of the presence of blaCTX-M or mecA was correlated with phenotypic susceptibility to ceftriaxone (CTO) (E. coli [EC] and Klebsiella spp.[KL]) or oxacillin (SA), respectively.

Results

We identified a total of 5,937 VG results. The final analysis was performed on 2,356 cases where EC, KL or SA was identified. Isolates detected KPC and NDM by VG were excluded. 30 EC/KL were missed by VG in polymicrobial bacteremia. 7 polymicrobial positive BCs with coagulase-negative staphyloccocci were mislabeled as MecA positive MSSA. Among isolated detected by VG, there were the high sensitivity and specificity of CTX-M to identify CTO resistance (97.2% and 99.7% in EC and 91.4% and 99.2% in KL). For SA, the sensitivity and specificity of mecA were 100% and 99.6% to identify oxacillin resistance. 2 isolates with mecA positive by VG were reported as oxacillin-suscpetible.

Conclusion

Our results revealed that there is a high correlation between VG and phenotype. For SA, discrepancies between genotype and phenotype seem to be influenced by the presence of other organisms in the sample. Genotypic information seems reliable and should guide targeted therapy in bloodstream infections.

Disclosures

All authors: No reported disclosures.
2172. True Positivity of Common Blood Culture Contaminants among Pediatric Hospitalizations in the United States, 2009–2016
Authors: Spaulding Alicen B , Watson David , Dreyfus Jill , Heaton Phillip , Kharbanda Anupam
Published: October 2019

Background

Distinguishing blood culture (BC) results between common contaminants (CC) and truly pathogenic organisms can be challenging, especially among pediatric patients, but is important for effective clinical care. However, no recent studies have analyzed the true positivity of common BC contaminants in pediatric patients using linked laboratory data from a large national sample of United States hospitals.

Methods

We conducted a retrospective cohort study among patients ages < 19 using the Premier Healthcare Database (2009–2016), limiting to hospitals reporting ≥ 4 years of BC data and encounters with one of the five most frequent CC among laboratory-confirmed BC. True positivity was defined for each CC as a second positive BC within 48 hours among all BCs. A multivariable logistic regression model including all variables significant in univariate analyses was created comparing encounters: (1) with and without a second BC; and (2) second BC positive vs. negative, with corresponding adjusted odds ratios (aOR) and 95% confidence intervals (CI) reported.

Results

A total of 5056 isolates corresponding to 4915 encounters with a CC were included in this analysis; 3075 (61%) isolates had a second BC within 48 hours. Adjusted odds of a second BC were higher for encounters from urban (aOR: 1.73, 95% CI: 1.31, 2.29) and ≥ 500 bed hospitals (aOR 1.40, 95% CI: 1.20,1.63). True positivity was 20.2% for coagulase-negative staphylococci (CoNS), 5.9% for Bacillus spp., 5.2% for Viridans group streptococci, 5.0% for Diphtheroids spp., and 3.1% for Micrococcus spp. True positivity for CoNS was higher among neonates but all other organisms were higher for non-neonates (figure). Adjusted odds of true positivity were higher for encounters with chronic conditions (OR 1.44, 95% CI: 1.13, 1.82), a central line in place (OR: 1.65, 95% CI: 1.30, 2.10), per length of stay day (OR: 1.01 (1.01, 1.01), and with an intensive care unit admission (OR: 1.39, 95% CI: 1.08, 1.77).

Conclusion

True positivity varied substantially by organism, and in most cases was higher among non-neonates. Regional variations for conducting a second BC within 48 hours were found, and more seriously ill patient encounters were more likely to have a common contaminant be pathogenic.

Disclosures

All authors: No reported disclosures.
2177. The Impact of the BioFire® FilmArray® Gastrointestinal Syndromic Panel on the Management of Infectious Gastroenteritis due to Diarrheagenic E. coli Strains in a Large Community Hospital
Authors: Jackson Christoper Bryan , Astorga Brenda , Gawrys Gerard , Reveles Kelly R , Lee Grace
Published: October 2019

Background

PCR-based rapid diagnostic tests (RDTs) provide rapid and accurate infectious gastroenteritis (IGE) etiologies within hours. However, there are limited data evaluating the impact of these panels on the appropriate management for diarrheagenic E. coli strains (DECS). This study evaluated the impact of the BioFire® FilmArray® GI panel on the appropriate antimicrobial management of DECS.

Methods

A retrospective analysis was conducted at a large community hospital in San Antonio, TX. Patients with a positive infectious diarrhea diagnostic panel (IDDP) for DECS from October 1, 2016 through September 30, 2018 and admitted for ≥48 hours were included. Patients were excluded if they had a positive IDDP for multiple DECS. An algorithm based on all available literature was used to classify appropriate management of DECS, which included patients having prolonged diarrhea (≥7 days), immunocompromised hosts (ICHs), or the presence of systemic symptoms. Antimicrobial therapy changes based on IDDP results, presence of an ID consult, and incidence of hemolytic uremic syndrome (HUS) were evaluated.

Results

A total of 374 patients were included for analysis. Overall, the IDDP did not lead to a change of therapy in 290 cases. However, the IDDP resulted in 84 antimicrobial changes including initiation of appropriate antibiotics (n = 48) and de-escalation/discontinuation (n = 22), primarily in special populations, such as ICHs. The IDDP results led to appropriate therapy optimization in 63%, 17%, 16%, and 9% of enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC) cases, respectively. In contrast, 81% of Shiga toxin-producing E. coli (STEC) cases were inappropriately managed with antibiotics, and 33% developed HUS. Only 14% of all DECS cases generated an ID consult.

Conclusion

Of note, this study found that the IDDP did not lead to a change in the management of most pathotypes. However, it was associated with positive changes in the management of DECS in specific patients, particularly ICHs. RDTs assist providers in the timely identification and treatment of IGE pathogens, but both antimicrobial and diagnostic stewardship remain critical for the optimal management of DECS.

Disclosures

All authors: No reported disclosures.
2184. Effect of Adjusted CLSI Breakpoints on Center-wide Fluoroquinolone Susceptibilities for Enterobacteriaceae and Pseudomonas aeruginosa: Is It Time to Restrict Empiric Fluoroquinolone Use?
Authors: Sansom Sarah , Moore Nicholas M , Kazi Aamir S , Won Sarah Y
Published: October 2019

Background

In January 2019, the Clinical and Laboratory Standards Institute (CLSI) lowered breakpoints of fluoroquinolones (FQ) for Enterobacteriaceae (EB)and Pseudomonas aeruginosa (PsAr). Automated commercial antimicrobial susceptibility testing (cAST) can only report levofloxacin MIC ≤1 μg/mL according to 2018 breakpoints. Updated panels will not be available until FDA approval. Laboratories and antimicrobial stewardship programs (ASP) must decide how to implement the adoption of new FQ breakpoints.

Methods

All microbiologic isolates of EB or PsAr were collected March 11, 2019–March 22, 2019. Manual E-tests and cAST by Microscan were performed for levofloxacin. Susceptible or non-susceptible (NS) isolates to levofloxacin were identified using 2018 and 2019 CLSI breakpoints [Table1]. Data were analyzed by Microsoft Excel and SPSS.

Results

159 isolates were analyzed. Isolates were predominantly from urine (78%) and females (68%). E.coli was the most frequently identified organism (40%) [Figure 1]. Application of new breakpoints changed 7% of EB (P = 0.083) and 16% of PsAr (P = 0.238) from susceptible to NS. [Figure 2] PsAr had higher rates of FQ NS compared with EB with new breakpoints (37% vs. 22%, P = 0.132, not shown). Non-urine and inpatient isolates had decreased susceptibility of ≥10% (P = 0.168 and 0.117). Lack of other resistance mechanism (ESBL, CRE, MDRO) was associated with a change in susceptibility (P = 0.036). Diagnosis of active cancer or immunosuppression (IS) was strongly associated with FQ NS by new breakpoints (P = 0.019, not shown). Patients with cancer or IS had the largest decrease in susceptibility (18%, P = 0.069) with application of new breakpoints. [Table 2].

Conclusion

Updated CLSI FQ breakpoints resulted in trends of increased resistance. PsAr, non-urine and inpatient isolates were disproportionately affected. Implementation of manual MIC determination from select clinical isolates may be useful until approval of updated cAST. Diagnosis of cancer or IS was associated with FQ NS by new breakpoints. Restriction of FQ for empiric use may be considered, particularly in patients with cancer or IS. Larger studies are needed to determine the long-term effects of adjusted FQ breakpoints, but are anticipated to have significant impacts on ASP.

Disclosures

All authors: No reported disclosures.
2190. Influence of Microbiological Culture Results on Antibiotic Choice for Veterans with Hospital-Acquired Pneumonia
Authors: Lee Anne. Christian Robbie , Sims Sharanie , Zappernick Taissa , Wilson Brigid , Perez Federico , Bonomo Robert A , Jump Robin L
Published: October 2019

Background

Respiratory specimens help inform the treatment of hospital-acquired pneumonia (HAP), permitting clinicians to ensure effective and, ideally, narrow-spectrum antibiotic therapy. Here, we examine changes in antibiotic regimens to treat HAP based on the antibiotic susceptibility of pathogens recovered from respiratory samples.

Methods

At a single Veterans Affairs (VA) Medical Center, we identified veterans hospitalized between October 2014 and September 2018 with HAP, defined as a clinical respiratory sample obtained >48 hours after admission and corresponding clinical signs and symptoms. Exclusion criteria were death, transfer to hospice care or discharge within 48 hours of sample collection or admission from an outside hospital. For each specimen, we assessed timestamps for collection, Gram stain, identification of organisms and results of susceptibility testing. We used the antibiotic spectrum index (ASI) to assess changes in antibiotics given to patients during hospitalization and at discharge.

Results

Between October 2014 and September 2018, 70 veterans met our inclusion criteria and experienced 73 episodes of HAP. Their mean age was 66.2 years (±9 years) and 47 (67%) had chronic pulmonary disease. All-cause mortality at 30-days after specimen collection was 14%. The median time from specimen collection to Gram stain result was 0.8 days (interquartile range (IQR) 0.1–1.9) and to antibiotic susceptibility results was 2.4 days (IQR 1.5–3.3). The most common bacteria recovered were Enterobacteriaceae (20 isolates), Pseudomonas aeruginosa (11 isolates), Streptococcus spp. and Staphylococcus aureus (8 isolates each); colonization with Candida spp. was frequent (26 isolates). Vancomycin and piperacillin–tazobactam were the most common antibiotics on day 0 (24%, 22%, respectively) and day 3 (21%, 13%, respectively). Compared with the day of sample collection (day 0), the ASI score was lower at day 3 in 23 (32%) and higher in 21 (29%) cases.

Conclusion

The high proportion of escalation and de-escalation of antibiotics suggests that results of bacteria identification and susceptibility testing influence therapeutic decisions, emphasizing the importance of obtaining respiratory samples to inform treatment of HAP and improve antibiotic stewardship.

Disclosures

All authors: No reported disclosures.
2192. Comparative Antimicrobial Susceptibility of Gram-Negative Bacteria Isolated from Patients with Bloodstream Infections and Pneumonia when Tested against Tazobactam Combinations
Authors: Carvalhaes Cecilia G , Mendes Rodrigo E , Flamm Robert K , Sader Helio S
Published: October 2019

Background

Cefepime–tazobactam (FEP-TAZ) is in clinical development at 2g/2g q8 hours administered over 90 minutes (high-dose extended infusion). We compared the susceptibility (S) of Gram-negative bacilli (GNB) from patients with bloodstream infections (BSI) and pneumonia (PN) against FEP-TAZ, piperacillin–tazobactam (PIP-TAZ), and ceftolozane–tazobactam (C-T).

Methods

In 2018, 3,389 GNB isolates (1/patient) were consecutively collected from patients with BSIs (1,349) and PN (2,040) in 40 United States (US) medical centers, and tested by reference broth microdilution methods for S against FEP-TAZ (TAZ at fixed 8 mg/L), PIP-TAZ, C-T, and comparators. The percentage of isolates inhibited at ≤8 mg/L (CLSI, cefepime high dose) and at ≤ 16 mg/L (pharmacokinetic/pharmacodynamic [PK/PD] S breakpoint based on extended infusion and high dosage) of FEP-TAZ were evaluated.

Results

FEP-TAZ (MIC50/90, 0.06/0.25 mg/L) was the most active TAZ combination against Enterobacterales (ENT) with a spectrum similar to that of meropenem (MEM; 99.3/97.2%S for BSI/PN), ceftazidime–avibactam (CAZ-AVI; 99.8/99.9%S), and amikacin (AMK; 99.3/98.3%S) and retained good activity against ceftriaxone-non-S (CRO-NS) and multidrug-resistant (MDR) ENT (table). Among the β-lactams (BLMs) tested, only FEP-TAZ (57.1/58.6% [BSI/PN] inhibited at ≤ 16 mg/L) and CAZ-AVI (71.4/96.6%S) were active against carbapenem-resistant ENT (CRE). CAZ-AVI (96.7/95.2%S for BSI/PN) and C-T (96.5/94.5%S) were the most active BLMs tested against P. aeruginosa (PSA), followed by FEP-TAZ (95.0/92.1% inhibited a ≤ 16 mg/L), FEP (89.3/78.2%S), and CAZ (85.1/79.0%S). FEP-TAZ (77.8/77.3% inhibited at ≤ 16 mg/L), C-T (81.2/82.9%S), and CAZ-AVI (77.8/84.5%S) retained activity against MEM-NS PSA. FEP-TAZ was the most active BLM against Acinetobacter spp. when the proposed PK/PD breakpoint was applied.

Conclusion

S rates were markedly lower among isolates from PN compared with BSI. FEP-TAZ was the most active TAZ combination tested against GNB isolated from patients with BSI and PN from US hospitals and exhibited greater spectrum than the carbapenems. The results of this study support further clinical development of high-dose extended-infusion FEP-TAZ for treatment of GNB infections.

Disclosures

All authors: No reported disclosures.
2194. Procalcitonin-Guided Antibiotic Strategy for Lower Respiratory Tract Infections: Outcomes and Safety of Withholding Antibiotics
Authors: Bambino Geno Tai Don , Goldstein Robert
Published: October 2019

Background

Procalcitonin (PCT) is a promising and well-studied marker in differentiating viral from bacterial lower respiratory tract infections (LRTI). Antibiotics are not recommended when PCT is normal (< 0.25 μg/L). Despite this, it has not been the standard of care due to safety concerns of relying on PCT to withhold antibiotics.

Methods

We retrospectively reviewed all non-critical LRTI patients with normal PCT admitted in our institution from October 2018 to March 2019. They were divided into adherent group in whom antibiotics were discontinued within 24 hours and non-adherent group in whom antibiotics were continued. Cases of Legionella, Mycoplasma, and other infectious syndromes necessitating antibiotics were excluded. Complexity of cases was measured based on Centers for Medicare and Medicaid Services (CMS) case-mix index (CMI). Outcomes compared were the length of stay (LOS), in-hospital mortality, and 30-day all-cause readmissions.

Results

A total of 78 patients were included in the analysis, 52% (n = 41) were in adherent group and 48% (n = 37) in the non-adherent group. The mean age was 74, and majority were females (59%, n = 46). The were no significant differences between the two groups in terms of age, gender, CMI, underlying COPD/asthma, CHF (see Table 1). The adherent group had statistically shorter LOS compared with the non-adherent group after adjusting for CMI. There was no significant difference in In-hospital mortality and readmissions (see Table 2). Furthermore, the adherent group’s LOS was statistically similar to CMS average LOS (5.08 vs. 3.8, P = 0.08); compared with the non-adherent group which had statistically longer LOS compared with CMS average LOS (8.3 vs. 4.6, p

Conclusion

PCT is a safe tool in deciding when to withhold antibiotics on LRTI patients. It shortens LOS with no difference in mortality or readmission.

Disclosures

All authors: No reported disclosures.
2195. Incidence of Acute Myocardial Infarction in Patients with Community-Acquired Pneumonia: A Systematic Review and Meta-Analysis
Authors: Nieto Dominguez Alejandro , Furmanek Stephen , Ramirez Julio
Published: October 2019

Background

Community-acquired pneumonia (CAP) is a respiratory disease that is responsible for an estimated 3.5 million worldwide deaths annually. In the last few years, it has been hypothesized that CAP is implicated in the development of diseases in other systems such as renal and cardiovascular. Until this moment, multiple studies evaluating incidence of acute myocardial infarction (AMI) in patients with CAP exist, but data are still unclear. Our objective was to summarize several studies available regarding incidence of Acute Myocardial Infarction (AMI) in patients with CAP and to compare such value with the incidence of AMI in the general population.

Methods

We conducted a systematic review of articles published between January 1980 and January 2019 in the PubMed and PubMed Central databases. Studies describing the incidence of AMI in patients with CAP were included. We extracted their diagnostic criteria for CAP and AMI, and their AMI follow-up periods. In addition to this, we calculated cumulative incidence of AMI in patients with CAP and compared such value with the general population.

Results

1841 studies were identified (Figure 1), of which 10 studies were included in our review (Figure 2). From a forest plot-random effects model, the cumulative incidence of AMI among patients hospitalized due to CAP was 2,440 per 100,000 (95% CI: 1,780; 3,320) (Figure 3). Using the age-adjusted incidence of 649 cases of CAP per 100,000 adults described by Ramirez et al., we estimated that 16 per 100,000 adults will have an AMI associated with CAP (95% CI: 12;22) per year in the US Moreover, Yeh et al. found that the incidence of AMI in the general population was 208 per 100,000 people, comparing this value, to the values obtained in our meta-analysis of 2,440 acute myocardial infarctions by 100, 000 people, we can infer that adult patients hospitalized due to CAP have an 11.7-fold increase from the general population for risk of MI.

Conclusion

A higher risk of AMI was observed among adults hospitalized with CAP compared with the general population. Results must be carefully analyzed given the heterogeneity of the studies. At a clinical level, this increase in AMI incidence in patients with CAP should be taken into account in order to give the best therapeutic management to such patients.

Disclosures

All authors: No reported disclosures.
2196. Impact of Rapid Discontinuation of Empiric Vancomycin in Patients with Hospital-Acquired or Healthcare-Associated Pneumonia and Absence of Adequate Respiratory Tract Culture Data
Authors: Rufe Alanna H , Johnson Linda S
Published: October 2019

Background

Vancomycin is a commonly utilized empiric therapy for patients with hospital-acquired and healthcare-associated pneumonia (HAP and HCAP). De-escalation is encouraged in the guidelines but not commonly performed in the absence of culture data. Studies have shown that in certain low-risk patients, vancomycin may not be necessary. A clinical criterion document was implemented in 2018 at CHI Memorial to facilitate rapid de-escalation of vancomycin. This study aims to assess the impact of early discontinuation of vancomycin in patients with HAP or HCAP and no respiratory culture.

Methods

A retrospective cohort analysis was conducted in adult inpatients who presented from September to December 2017 and 2018 with HAP or HCAP, no respiratory culture within 72 hours, and at most one risk factor for MRSA. Patients who did not meet criteria for de-escalation, were receiving antibiotics for an extrapulmonary infection, or had a pathogen identified from blood or urinary antigen tests were excluded. The primary endpoint was vancomycin days of therapy pre- vs. post-intervention. Secondary endpoints include vancomycin re-start, subsequent respiratory culture growing MRSA, intensive care unit (ICU) and total length of stay, total days of antibiotic therapy, total days of alternate anti-MRSA therapy and in-hospital mortality in de-escalated vs. non-de-escalated patients.

Results

A total of 66 patient were included; 25 in the pre- and 41 in the post-period. The median age was 83 in the pre- and 68 in the post-period, with 20% of patients being initiated in the ICU and one patient with HAP in each group. There was no difference in median days of vancomycin therapy in the pre- vs. post-intervention period (4 days [3–5] vs. 4 days [3–5]) P = 0.583. There were 37 patients not de-escalated and 29 patients rapidly de-escalated. Total days of inpatient antibiotic therapy was significantly lower in the de-escalated group (7 days [5–9] vs. 5 days [4–7]) P = 0.037. No other significant differences were noted (Table 2).

Conclusion

There was no difference in vancomycin days of therapy after the implementation of this pharmacist-led initiative. However, discontinuing vancomycin within 72 hours was safe in patients with HCAP and was associated with decreased days of inpatient antibiotic therapy.

Disclosures

All authors: No reported disclosures.
2197. Ceftriaxone Monotherapy vs. Ceftriaxone Plus Azithromycin for the Treatment of Community-Acquired Pneumonia in Hospitalized, Non-ICU Patients
Authors: Murter Forrest , Dimond Kristin , Gilstrap Christopher , Grubbs Riley , Vowell Clark , Maldonado Cody , Jansen Jeffrey W
Published: October 2019

Background

Community-acquired pneumonia (CAP) is the leading infectious cause of death and severe sepsis in the United States and the fifth leading cause of death overall worldwide. Current United States guidelines for the treatment of CAP recommend empiric antibiotic therapy that covers both standard organisms as well as atypical organisms. Ceftriaxone (CTX) in combination with azithromycin (AZH) is one of the most common regimens used for the treatment of CAP; however, there are studies that show β-lactam monotherapy is as effective as a β-lactam in combination with AZH for the empiric treatment of CAP. The purpose of this study was to compare the rates of treatment failure between CTX monotherapy and CTX in combination with AZH in non-intensive care unit (ICU) inpatients.

Methods

Non-ICU hospitalized patients ≥ 18 years old admitted to Saint Vincent Healthcare with a primary or secondary ICD-10 code of pneumonia from 2013 to 2018 were included. Patients were excluded if they were pregnant, admitted within 2 weeks of a previous episode of CAP, were admitted to the ICU, had cystic fibrosis, or were given antibiotics with atypical coverage (other than azithromycin) prior to admit or within 24 hours of presentation. The primary outcome was treatment failure defined as a composite of any of the following: (1) attributable mortality, (2) in vitro resistance, and (3) change of antibiotic class. Secondary outcomes included length of stay, antibiotic duration, time to oral antibiotics, and readmission within 30 days.

Results

There were 84 and 159 patients included in the CTX and CTX+AZH groups, respectively. Baseline demographics between groups are shown in Table 1. The composite primary endpoint occurred in 22 patients (26.2%) in the CTX group and in 48 patients (30.2%) in the CTX + AZH group. After adjusting for gender, race, in hospital death, chronic obstructive pulmonary disease, length of therapy, length of stay, and systemic inflammatory response syndrome, CTX monotherapy was no less effective than CTX+AZH (aOR 0.55; 95% CI: 0.27 to 1.1; P = 0.09). The primary endpoint and secondary endpoints are shown in Tables 2 and 3, respectively.

Conclusion

There was no difference between CTX monotherapy and CTX + AZH for the empiric treatment of CAP.

Disclosures

All authors: No reported disclosures.
2200. Cost-effectiveness of Ceftolozane/Tazobactam for Treating Ventilated Nosocomial Bacterial Pneumonia
Authors: Naik Jaesh , Yang Joe , Elsea David , Critchlow Simone , Puzniak Laura
Published: October 2019

Background

Ventilated, hospital-acquired and ventilator-associated bacterial pneumonia (vHABP/VABP) are associated with high rates of antibiotic resistance and high morbidity and mortality in hospitalized patients. Ceftolozane/tazobactam (C/T) has shown non-inferiority to meropenem for treating HABP/VABP in a Phase III trial, ASPECT-NP. This study evaluates cost-effectiveness of C/T against meropenem in treating HABP/VABP.

Methods

We developed a model consisting of a short-term decision tree (reflecting the in-hospital period) followed by a long-term Markov structure (capturing lifetime costs and outcomes). Patient characteristics and clinical efficacy were informed by subjects in ASPECT-NP who received any dose of study drugs. Susceptibility was based on the Program to Assess C/T Susceptibility surveillance database. Second-line and salvage treatment were added to resemble real-world treatment patterns and used to calculate overall clinical cure and mortality rates based on results from a network meta-analysis. We analyzed two clinical scenarios: (1)”confirmed treatment’ in which C/T or meropenem is used after pathogen susceptibility is known; (2) ‘initial treatment’ of high-risk patients before susceptibility is known. Model outcomes include, percentage clinically cured, short-term mortality, direct medical costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios. Sensitivity analyses (SAs) were conducted to test the robustness of results.

Results

In the confirmed treatment setting, C/T had a higher cure rate (5.0 percentage points, the same below), lower short-term mortality (−5.1%), cost more ($2,728), and yielded higher lifetime QALYs (0.61) than meropenem ($4,472/QALY gained). In the initial treatment setting, C/T sustained a better clinical performance (9.5% more cure, −6.8% mortality, 1.16 more QALYs), yet cost less than meropenem (−$5,662) due to better susceptibility. The response and mortality rates from ASPECT-NP had the greatest impact on results. SAs showed that the result of C/T being cost-effective over meropenem was generally robust.

Conclusion

The results indicate that, compared with meropenem, C/T could be a cost-effective option for patients with vHABP/VABP in the US setting.

Disclosures

All authors: No reported disclosures.
115. Evaluation of the Clinical Impact of the T2MR for the Diagnosis of Bloodstream Infections
Authors: Seitz Tamara , Baumgartner Sebastian , Wenisch Christoph , Zoufaly Alexander
Published: October 2019

Background

The EK-189 study evaluates the clinical impact of T2 magnetic resonance (T2MR) for rapid detection of bloodstream infections (BSI) caused by ESKAPE-pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Escherichia coli) compared with blood culture (BC). Here we present preliminary results from this ongoing study.

Methods

Patients newly admitted to an infectious diseases department with suspected blood stream infection with ESKAPE pathogens (based on predefined criteria) are included and randomized into BSI diagnosis with (a) T2MR and blood culture or (b) blood culture alone. Routine diagnostic workup including chest X-ray, complete laboratory workup (including blood count, C-reactive protein, interleukin-6) is performed in all patients. Antibiotic regimens are selected empirically based on suspected pathogens and are switched to targeted therapy at the discretion of the treating physician once a pathogen is detected. Outcome parameters include time to targeted (predefined) antibiotic therapy and time to discharge. Test characteristics of the T2MR compared with BC are also assessed.

Results

So far 44 patients were included (22 in each group). In 9/22 patients (41%) in the T2MR-group a pathogen was detected (4 Escherichia coli, 2 Klebsiella pneumoniae, 1 Staphylococcus aureus, 1 Pseudomonas aeruginosa and 1 Acinetobacter baumanii) and in 3/22 (14%) patients in the BC-group (all E. coli). The comparison of T2MR vs. BC is depicted in Table 1. Sensitivity and specificity of T2MR in comparison to BC were 100% and 64.7%. All positive results in T2MR were considered true positive results. The days until clinical improvement, the need for admission at ICU and the in-hospital mortality were similar in both groups.

Conclusion

The results from this preliminary analysis show that in patients with suspected BSI with ESKAPE pathogens, T2MR detects more pathogens than BC and potentially provides a quicker detection and shorter time to targeted therapy. Further analyses of this ongoing study with a larger sample size are needed to evaluate the impact of the use of T2MR on patient’s outcome

Disclosures

All authors: No reported disclosures.
2223. Real-time Prediction of Respiratory Pathogen Infection Based on Machine Learning Decision Support Tool
Authors: Nir-Paz Ran , Almogy Gal , Keren Arie , Livne Guy , Amit Sharon , Wolf Dana , Moses Allon E
Published: October 2019

Background

Respiratory pathogens are a common cause of disease. Currently there is not a practical tool to predict the putative etiology of each case with an inexpensive, fast point-of-care assay. Here, we describe a decision support tool that enables the prediction of both bacterial and viral respiratory pathogen infections in a single patient, using a Machine Learning model.

Methods

The data were obtained from the Hadassah-Hebrew University Medical Center during a period of 10 years beginning from 2007 and contained more than 40,000 patients from a 1,000,000-population community for whom specimens were tested by either PCR or culture. The pathogens included were, H. influenzae; M. catarrhalis; S. pneumoniae; M. pneumoniae; Adenovirus; Human metapneumovirus; Influenza H1N1, A, B; parainfluenza 1,2 and 3; and RSV. We then created a Machine-Learning algorithm to simulate the spread of infection in the entire Jerusalem area. We defined transmission areas based on geographical distances of patients’ home-addresses. Then we prospectively tested the tool accuracy over a 4-month period, in addition to real-time improvement of the model.

Results

Initial model was created based on gender, age, home addresses and the diagnostics test results. We then reconstructed a putative spread pattern for each of the pathogens that can be correlated to potential “transmission routes.” The initial prediction tool had an AUC for most pathogens around 0.85. It ranged from 0.75 to 0.8 for the bacterial and 0.82 to 0.89 for the viral pathogens. In almost all pathogens the NPV was 0.98–0.99. We then tested the decision support tool prospectively over four consecutive months (January to April 2019—1,700 patients with respiratory complaints from whom samples were sent to the lab). While the AUC in the prospective cohort was 0.81 on average, the NPV remained high on 0.98.

Conclusion

The implementation of the decision support tool on respiratory pathogen diagnostics enables better prediction of patients not infected with either viral or bacterial pathogens. The use of such a tool can save more than 50% of diagnostic tests expenses as well as real-time mapping of disease spread. Improvement of the Machine Learning protocol may further promote the optimization of positive predictive values.

Disclosures

All authors: No reported disclosures.
119. Nocardia Bacteremia Is Almost Always Associated with Immune Compromise or an Intravascular Device: Single-Center Case Series and Systematic Review of the Literature
Authors: Williams Eloise , Jenney Adam W , Spelman Denis W
Published: October 2019

Background

Nocardia bacteremia is a rare but important phenomenon, with previous studies describing a 50% mortality rate. We undertake a single-center review and the largest systematic review of Nocardia bacteremia performed over the past 20 years.

Methods

A single-center review of cases of Nocardia bacteremia was performed using hospital microbiology records from January 1, 2010 to December 31, 2017. A systematic literature review was also performed to identify cases of Nocardia bacteremia described in the English language literature between January 1, 1999 and December 31, 2018 using the NCBI PubMed database and snowballing from citations of relevant publications.

Results

Single-center case series: Four cases of Nocardia bacteremia are described. Three patients had an intravascular device in situ prior to the onset of Nocardia bacteremia and three patients were immunocompromised; one patient had both risk factors. Systematic literature review: A systematic review identified 50 publications that described 85 cases with sufficient patient data to be reviewed in detail. Including the 4 cases described in our institution, 89 cases of Nocardia bacteremia were included in the analysis. The median age was 57 years [interquartile range (IQR) 42–68] and 69% were male. Eighty-two percent of cases were immunocompromised and 38% had endovascular devices. Pulmonary infection was the most common concurrent site of clinical disease (66%), followed by central nervous system (25%), pleural (17%) disease, and endocarditis (11%). Blood cultures were the only positive microbiological specimen that isolated Nocardia in 45% of cases. Median incubation time to blood culture positivity was 4 days [IQR 3–6]. Thirty-day all-cause mortality was 24% and overall all-cause mortality was 42%.

Conclusion

Four new cases of Nocardia bacteremia are described. Isolation of Nocardia from blood cultures is rare but represents serious infection with high associated overall mortality. Nocardia bacteremia is most frequently identified in immunocompromised patients and those with intravascular devices.

Disclosures

All authors: No reported disclosures.
2263. Fosfomycin Trometerol Use for Complicated UTIs Including Pyelonephritis, a 1-year Review of Outcomes and Prescribing Habits
Authors: Hatlen Timothy J , Flor Richard , Nguyen Megan , Miller Loren G
Published: October 2019

Background

Treatment of complicated urinary tract infections (UTI) caused by multidrug-resistant organisms (MDROs) is increasingly problematic given limited oral antibiotic options. In these situations, fosfomycin is increasingly used. However, there are limited outcome and pharmacokinetic data to support fosfomycin use for complicated UTIs (cUTI), especially in the upper tract. We describe fosfomycin use for complicated cUTI in our healthcare system.

Methods

We performed a retrospective review of all fosfomycin prescriptions between 1/1-December 31/17 in the Los Angeles Department of Health Service system, which consists of 4 medical centers and 19 clinics that provide care to >600,000 patients annually. In our system, fosfomycin use requires ID approval. We collected demographics, clinical characteristics, adverse effects, and 30-day success rates. Subsequent urine cultures up to December 31/18 were examined for fosfomycin susceptibility.

Results

A total of 156 patients received fosfomycin; 21 (13%) had lower UTI, 39 (25%) had lower tract cUTI, 24 (15%) had upper tract not pyelonephritis, and 37 (24%) had pyelonephritis. The majority (n = 98, 63%) were female, 82 (53%) had urological or functional abnormalities, 67 (43%) had diabetes, 26 (17%) were immunocompromised and most (n = 135, 87%) presented from the community. E.coli was the predominant pathogen (n = 123, 79%), 112 (91%) of these produced ESBL. For cUTI (n = 100), dosing interval was q24h (3%), q48h (51%) and q72h (46%). Among patients with 30-day outcomes (n = 100, 64%), success was seen in 84 (84%), and was 79% (14/64) among those with cUTI. Failure was associated with male gender (p = 0.005), urological abnormalities (p = 0.047), and non-E. coli UTIs (p = 0.03). Only 1 adverse effect at 30 days was described. Fosfomycin-resistant E. coli were found in 9/64 (14%) of patients with follow-up urine cultures > 30 days after initial treatment (mean 5.7 ± 4.03 mo.).

Conclusion

Despite the lack of data supporting its use, we found that most patients receiving fosfomycin for complicated upper UTIs had clinical success. However, emergence of subsequent resistance warrants caution. Further studies should be done to better understand optimal use of fosfomycin for complicated UTIs.

Disclosures

All authors: No reported disclosures.
2264. An Evaluation of Empiric Treatment Patterns for Adult Patients with Community-Onset (CO) “Low-Risk” (LR) Complicated Intra-Abdominal Infections (cIAI) Across US Hospitals
Authors: Lodise Thomas , Izmailyan Sergey , Olesky Melanie , Lawrence Kenneth , Tsai Larry
Published: October 2019

Background

Current cIAI guidelines recommend that broad-spectrum antibiotics (abs) like anti-pseudomonal β-lactams should be reserved for “high-risk” CO cIAI patients. Fluoroquinolone (FQ) use is also discouraged in geographic areas with a high incidence of FQ-resistance. Compliance with these recommendations are unclear as there are limited data on empiric treatment (tx) patterns for adult patients with cIAI across US hospitals. This study sought to evaluate empiric tx patterns for patients with CO LR cIAI and assess compliance with cIAI guideline recommendations.

Methods

A retrospective multi-center study using data from the Premier Research Database (October 2015–December 2017) was performed. Inclusion criteria: age ≥ 18 years; hospitalized; primary cIAI diagnosis and a cIAI surgical procedure or a secondary cIAI diagnosis and cIAI surgical procedure within 5 days of admission; and received an ab within first 4 hospital days. For patients with multiple cIAI admissions, only the first cIAI was considered. Apt was classified as high-risk (HR) if they met any one of the following criteria: sepsis, severe sepsis, septic shock; ≥3 components of sepsis; or ≥2 two physiologic risk factors (age ≥ 70 years, malignancy, kidney dysfunction, hepatic dysfunction, hypoalbuminemia, and significant cardiovascular compromise). Empiric tx was abs received during the first 4 hospital days. Incidence of empiric tx regimen including one of the following abs was determined among LR patients: piperacillin/tazobactam (TZP), meropenem (MER), cefepime (CFP), and FQ.

Results

Overall, 70,275 patients met study criteria; 11,382 (16%) were HR and 58,893 (84%) were LR. Among LR CO cIAI patients, the mean (SD) age was 54.3 (18.1), 52% were male, and the median (IQR) for Charlson Comorbidity Index was 0 (0–1). The most common diagnosis among LR patients was acute appendicitis with peritonitis (53%). The 10 most common empiric antibiotics administered are shown in table. Among LR patients, 52% received TZP, 3% received MER, 3% received CFP, and 20% received a FQ; 8% received ≥2 of these agents.

Conclusion

Overuse of non-guideline concordant broad-spectrum abs was commonplace among CO cIAI patients classified as LR. These findings can serve as the basis for an antimicrobial stewardship initiative in hospitals aspiring to reduce the use of broad-spectrum antibiotics.

Disclosures

All authors: No reported disclosures.