bluuebunny/crossref_metadata_2025_split huggingface dataset:
160. Could Reducing Time to Bacterial Identification From Positive Blood Cultures Improve Outcomes in Bacteremic Patients?
Authors: Forbes Jessica D , Haj Reem , Taggart Linda R , Fattouh Ramzi , Leung Elizabeth , Friedrich Jan , Matukas Larissa M 
Published: October 2019

Abstract

Background
Survival of patients with septic shock is dependent on the timing of effective antibiotic administration. The initial notification by the microbiology lab of a positive blood culture is a key factor in improving patient outcomes. It can take >24 hours to definitively identify bacteria from positive blood cultures. Accordingly, we employed rapid organism identification and studied the impact of this on patient management from a quality improvement perspective.

Methods
Rapid organism identification was performed for bacteremic patients admitted to an ICU at St. Michael’s Hospital in Toronto, ON, by creating a pellet from positive blood culture bottles using a lysis centrifugation technique. MALDI-TOF was then used to obtain an organism identification. The microbiology lab verbally notified the ward clerk of the identification and surveys were conducted with treating physicians within 24–48 hours to evaluate the downstream impact of the rapid identification including changes to antibiotics, diagnostic testing, central line management and requests for specialty consultations.

Results
Between January 28 and April 28, 2019, 17 rapid blood culture results were included for study. When asked how physicians received the result, in 7 cases the physician did not remember; other responses included microbiology report (2), nurse (2), pharmacist (1), antimicrobial stewardship or lab (1), on-call team (1) and residents (1). Antibiotics were adjusted in 13 patients; 3 of which may have changed antibiotics for reasons other than the organism identification. Reasons for not changing therapy include: appropriate empiric treatment, likely contaminants, or physician not being notified of the result. In 5 cases, all antibiotics were discontinued, in another 2 cases the antibiotics were broadened and a further 5 narrowed to cover the organism; the remaining 5 continued the same empiric therapy. Repeat blood cultures were obtained for 5 cases, follow-up imaging in 5 cases and lines were changed/removed in 5 cases. Consultation was requested for 7 cases.

Conclusion
Based on preliminary data, rapid organism identification shows promise of improved patient management with line removal and antibiotics adjustments occurring 1 day sooner with rapid results.

Disclosures
All authors: No reported disclosures.
2672. Clostridioides difficile Infection Among Bone Marrow Transplant Recipients: Findings From a Single Institution
Authors: Thomas Christine , Hagen Patrick , Henry Elizabeth , Joyce Cara J , Berg Stephanie 
Published: October 2019

Abstract

Background
Clostridioides difficile infection (CDI) is increasingly common among hematopoietic stem cell transplantation (HSCT) recipients and efforts to define CDI risk have shown variable results. The primary objective of this study was to further characterize CDI incidence and risk factors in HSCT recipients.

Methods
All allogeneic and autologous HSCT recipients at Loyola University Chicago between January 2011 and May 2017 were retrospectively reviewed for development of CDI within 6 months prior to 2 years following HSCT. Collected data include comorbid conditions, statin or proton pump inhibitor (PPI), and antimicrobial use. HSCT baseline information was also obtained and include underlying malignancy, prior chemotherapy, graft type, conditioning regimen consisting of total body irradiation (TBI) use, and donor source (matched related or unrelated and umbilical cord blood). Among those with diagnosed CDI, data pertaining to CDI severity, treatment, and recurrence was collected. Logistic regression analyses were performed to estimate odds ratios for factors associated with development of CDI.

Results
Six hundred eighty-nine patients met our inclusion criteria. Of these, 367 (53%) underwent autologous HSCT and 322 (47%) allogeneic HSCT. Among all patients, 132 (19.1%) had CDI of which 26 (19.7%) had recurrence within 60 days. In univariable analysis, any type of leukemia was associated with increased odds of CDI compared with lymphoma (OR = 2.44, 95% CI: 1.49- 4.00, P < 0.01) as was allogeneic HSCT compared with autologous (OR = 2.51, 95% CI: 1.63–3.88, P < 0.01 for matched and OR = 3.96, 95% CI: 2.31–6.79, P < 0.01 for cord blood) and use of TBI (OR = 1.63, 95% CI: 1.10 – 2.40, P < 0.05). Exposure to any cephalosporin or intravenous vancomycin within 100 days of HSCT was associated with CDI (OR = 1.55, 95% CI: 1.03–2.32, P < 0.05 and OR = 1.75, 95% CI: 1.19–2.58, P < 0.01 respectively). No significant differences in the odds of developing CDI were identified by patient comorbidities, statin or PPI use.

Conclusion
In our population there was a 19% incidence of CDI. Underlying leukemia, TBI exposure, and allogeneic HSCT appear to be risk factors for CDI and further research is needed to evaluate whether exposure to cephalosporin or vancomycin may be modifiable risk factors.

Disclosures
All authors: No reported disclosures.
2678. Characterizing Hospitalizations and Infections Among Older Adults Receiving Palliative Chemotherapy for Hematologic Malignancies
Authors: Uy Natalie , Datta Rupak , Bar Noffar , Juthani-Mehta Manisha 
Published: October 2019

Abstract

Background
As cancer survivorship improves, the number of patients with hematologic malignancies receiving palliative chemotherapy will grow. Older adults with hematologic malignancies often carry poor prognoses and experience high risks of infection. We evaluated the frequency of CDC criteria confirmed infection and antimicrobial use during hospitalizations following initiation of palliative chemotherapy.

Methods
We conducted a cohort study of patients aged ≥65 years who received non-curative palliative chemotherapy between January 1, 2016 and September 30, 2017 and were subsequently hospitalized by January 31, 2018. Hematologic malignancies were verified with medical record review. Infections were identified using CDC criteria, and antimicrobials were categorized by indication for use.

Results
We identified 268 patients receiving palliative chemotherapy for hematologic malignancies (Table 1) who had a total 591 hospitalizations (Table 2) during follow-up. There were 162 readmissions (27%) among 92 patients. Among all patients, 128 (48%) died during follow-up. Forty-one (15%) deaths were within 30 days of discharge. The most common site of death was hospice, in and outpatient (27%). Two hundred forty-nine (42%) admissions were for infectious causes; of the 34 patients who died inpatient (non hospice), 56% had been admitted for infectious causes. Antimicrobials were prescribed for prophylaxis in 57% (n = 337/591) of hospitalizations. Antimicrobials were prescribed for suspected infection in 48% (n = 282/591) of hospitalizations. Only 30% (n = 178/591) of hospitalizations had antimicrobials given for CDC confirmed infections. Figure 1 shows the most common indications for antimicrobial use.

Conclusion
Infections are an important cause of the morbidity and mortality in older adults receiving palliative chemotherapy for hematology malignancies. Hospitalizations for infectious causes were frequent in our cohort. Nearly half of hospitalizations involved antimicrobial use for suspected infection, but CDC confirmed infections were less common. This population warrants further investigation to improve antimicrobial use. Future studies should identify the subset of patients at high risk for recurrent admissions to optimize medical care.

Disclosures
All authors: No reported disclosures.
2682. Prophylaxis-Driven Molecular Epidemiology of Pseudomonas aeruginosa Bloodstream Infections in Adults With Leukemia
Authors: Endres Bradley T , Buege Michael J , Marx Kayleigh , Sahasrabhojane Pranoti V , Galloway-Peña Jessica , Garey Kevin W , Kim Jiwoong , Greenberg David E , Zhan Xiaowei , Shelburne Samuel A , Shelburne Samuel A , Aitken Samuel L , Aitken Samuel L 
Published: October 2019

Abstract

Background
Fluoroquinolones (FQs) are routinely used as antimicrobial prophylaxis in leukemia patients receiving chemotherapy to prevent Pseudomonas aeruginosa infections. Patients who are intolerant to FQs may receive cefpodoxime (CPD) or other agents. How FQ use affects the resistance profile and epidemiology of breakthrough P. aeruginosa infections is unknown. To determine this, we performed a whole-genome sequencing (WGS)-driven epidemiologic study of leukemia patients with P. aeruginosa bloodstream infections.

Methods
All adult (age > 17 years) inpatients with leukemia and a first episode of monomicrobial P. aeruginosa bloodstream infection were included. Clinical data were extracted from the electronic medical record. Isolates were sequenced using an Illumina NextSeq and phylogenomics was performed using an in-house analysis pipeline consisting of Bowtie2, SAMtools and bcftools.

Results
110 patients were included and most had a diagnosis of acute myeloid leukemia (n = 66). Twenty (18%) patients received FQ prophylaxis, 56 (54%) received CPD, and the remaining 34 (31%) received other agents. 9 (8%) isolates were multidrug-resistant (MDR). MDR was more common in those receiving FQ prophylaxis (20% vs 6%, P = 0.06). 76 sequence types (STs) were represented with ST235 (n = 8) being most common followed by ST244 (n = 7). ST235 strains were genetically distinct, but closely related (>10 but < 250 SNPs) in comparison to other STs. 2 ST244 strains were genetically identical despite being isolated 4 months apart, suggesting horizontal transmission. MDR was more common among ST235 isolates compared with other STs (38% vs 6%, P = 0.02). ST235 strains were more common in patients receiving FQ vs other prophylaxis (20% vs 4%, P = 0.04). 1 ST244 isolate harbored a VIM-2 β-lactamase. In 20 FQ-resistant isolates, 80% had mutations in either parC (S87L) or gyrA (T83I) and 50% had both. FQ-resistance mutations were more common in FQ recipients (50% vs 8%, P < 0.01).

Conclusion
Most P. aeruginosa infections occurred in non-FQ recipients, while MDR P. aeruginosa infections were more common in FQ recipients. These data suggest that decisions on empiric treatment of patients with P. aeruginosa bacteremia must take antimicrobial prophylaxis history into account.

Disclosures
Samuel L. Aitken, PharmD, Melinta Therapeutoics: Grant/Research Support, Research Grant; Merck, Sharpe, and Dohme: Advisory Board; Shionogi: Advisory Board.
2686. strong>Bloodstream Infection Survey in High-Risk Oncology Patients (BISHOP) with Fever and Neutropenia (FN): Viridans Group Streptococcus Emerges as an Important Pathogen
Authors: Stohs Erica , Zimmer Andrea , Fey Paul , Handke Luke D , Zhang Yuning , Arnold Christopher , Baddley John W , Chandrasekar Pranatharthi , Boghdadly Zeinab El , Gomez Carlos A , Maziarz Eileen K , Montoya Jose G , Pergam Steven A , Rolston Kenneth , Satlin Michael J , Satyanarayana Gowri , Shoham Shmuel , Strasfeld Lynne , Taplitz Randy , Walsh Thomas J , Young Jo-Anne H , Freifeld Alison 
Published: October 2019

Abstract

Background
In this prospective nation-wide survey of bloodstream isolates associated with first episode of FN in high-risk cancer patients from 14 US cancer centers (December 2016 and June 2018), viridans group Streptococci (VGS) were the most common Gram-positive isolate. We sought to clinically and microbiologically characterize VGS bloodstream infections (BSI).

Methods
Among 343 patients,we compared 90 with VGS vs 253 with non-VGS BSI. Minimum inhibitory concentrations for blood culture isolates were determined by broth dilution for selected agents at our reference microbiology laboratory (UNMC). Clinical data were electronically captured in RedCap, including local site isolate identification and confirmatory reference lab identification via MALDI. Categorical and continuous variables were assessed via chi-square and Mann–Whitney U tests, respectively.

Results
Ninety-two VGS isolates were identified among 90 FN patients, representing 27% of all BSI isolates. S. mitis or oralis comprised 64 (70%) of VGS. There were no differences between age, sex, and primary diagnosis (50% with AML) among the 2 groups; 1/3 were HSCT recipients. Fluoroquinolone prophylaxis was used in 64 (71%) vs. 139 (55%), P < 0.01, in VGS vs non-VGS groups. Critical illness composite (new need for pressor(s), mechanical ventilation or death within 30 days) was 6 (7%) vs. 44 (17%), P = 0.01, in the VGS vs non-VGS groups. Figure 1 displays an overview of antibiotic susceptibilities for 79 testable isolates. VGS susceptibilities to levofloxacin, penicillin, and ceftriaxone were 39%, 47%, and 94%, respectively.

Conclusion
VGS are common pathogens in FN patients. Prior fluoroquinolone prophylaxis use may be a risk factor. VGS BSI was not associated with increased critical illness compared with non-VGS. Finally, assuming ceftriaxone susceptibility confers that of cefepime, >90% of VGS are susceptible to empiric FN cefepime regimens.

Disclosures
All authors: No reported disclosures.
2688. The Clinical Impact of Early De-escalation of Broad-Spectrum Antibiotics in Acute Myeloid Leukemia Patients with Febrile Neutropenia
Authors: Davis Matthew , Afifi Salma , McManus Dayna , Topal Jeffrey E 
Published: October 2019

Abstract

Background
In patients with febrile neutropenia (FN) the initiation of broad-spectrum antibiotics (BSA), an anti-pseudomonal agent +/− vancomycin, is recommended by national guidelines. BSA should be continued until absolute neutrophil count (ANC) recovery (ANC > 500 cells/mm3). With increasing antimicrobial resistance, clinicians are reassessing the need to continue BSA until count recovery; new data are emerging that patients may be able to have their BSA de-escalated if stable and afebrile. At our institution, some patients are de-escalated from BSA to a fluoroquinolone before ANC recovery and others are continued on BSA. The purpose of this study was to evaluate the efficacy and safety of early de-escalation compared with the standard of care.

Methods
We retrospectively reviewed acute myeloid leukemia patients receiving induction chemotherapy who developed FN while at Yale New Haven Hospital from March 2013 to August 2018. Patients were excluded if they developed a culture documented infection, received incomplete or multiple induction chemotherapy treatments, or died from underlying disease during hospitalization. The primary outcome was recurrent fever during admission and secondary outcomes included incidence of breakthrough infections (BI), duration of hospital stay, early discharge (discharge before ANC recovery), duration of BSA, and readmission within 7 days of discharge.

Results
A total of 210 patients were evaluated and 91 patients were included (de-escalation, n = 45; BSA, n = 46). Baseline characteristics are noted in Table 1. There was no statistical difference in rate of recurrent fever in patients who were de-escalated from BSA compared with those that were continued (P = 0.05). De-escalated patients had a shorter duration of BSA therapy (P < 0.05), earlier discharge (P = 0.05) and no difference in readmission rates (P = 0.39) (Table 2). There was no difference in rate of BI between both groups and all BI were bacteremias. (Table 3) No patients who experienced a BI died from infection.

Conclusion
The results of this study revealed no difference in the primary outcome of recurrent fever between the BSA and de-escalation groups. De-escalation led to a reduced duration of BSA and facilitated earlier discharge without increasing readmission rates and BI.

Disclosures
All authors: No reported disclosures.
2692. Comparison of Demographics and Risk factors Between Strongyloides stercoralis Seropositive and Seronegative Solid-Organ Transplant Candidates: Experience from a Tertiary Acute Care Center in Florida
Authors: Perez-Lopez Carlos J , Alrabaa Sally , Aslam Sadaf , Teo Greg Matthew E , Kim Teayoung , Reljic Tea 
Published: October 2019

Abstract

Background
Strongyloides stercoralis is a nematode endemic to the tropical and subtropical regions. In the United States, it is mostly found at southeastern states. Most infections are asymptomatic but disseminated and fatal infections have been reported in immunocompromised patients. At our institution, universal screening through Strongyloides antibody detection in serum among solid-organ transplant candidates began since 2010 and all seropositive candidates are treated before transplantation. We previously determined our incidence to be about 5%. The aim of this study was to determine demographic characteristics and risk factors that can be used for more cost-effective targeted screening.

Methods
We performed a retrospective cohort study of patients who underwent transplant evaluation from 2014 to 2016. A total of 228 charts were reviewed for Strongyloides serology status, eosinophilia, demographics and risk factors. Chi-square and Fisher exact tests were used to do a comparative analysis between Strongyloides seropositive and seronegative cohorts.

Results
We identified 113 seropositive (SP) patients and 115 seronegative (SN) patients. There were more males in the seropositive group (79%) compared with seronegative group (62%) (P = 0.005). Caucasians predominated in both groups (SP 71% vs. SN 57%; P = 0.286). No significant difference was found between both groups with regards to occupation with soil or water contact (SP 38% vs. SN 30%; P = 0.281), birthplace outside USA or travel outside of United States (SP 31% vs. SN 36%; P = 0.732). Eosinophilia occurred less in the seropositive group compared with the seronegative group (SP 16% vs. SN 30%; P = 0.030).

Conclusion
The study did not find any statistically significant difference in the demographic characteristics or risk factors that can be used for prediction of Strongyloides seropositivity among solid-organ transplant candidates. Hence, our institution will continue universal screening for Strongyloides stercoralis for all our transplant candidates. Our findings further question donor screening for Strongyloides that uses a similar questionnaire which may not be reliable to identify those infected with this parasite. This would put recipients at risk for a donor-transmitted infection.

Disclosures
All authors: No reported disclosures.
2695. Pneumocystis jirovecii Pneumonia in the Era of Effective Prophylaxis Following Hematopoietic Stem Cell Transplant
Authors: Drelick Alexander Christian , Kodiyanplakkal Priya , Plate Markus , Satlin Michael J , Soave Rosemary , Shore Tsiporah , Besien Koen Van , Small Catherine , Walsh Thomas J 
Published: October 2019

Abstract

Background
Pneumocystis jirovecii pneumonia is an uncommon and life-threatening disease that can occur following hematopoietic stem cell transplantation (HSCT). Trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis greatly reduces the incidence of PJP. We aim to determine what factors contribute to the development of PJP following HSCT where TMP-SMX prophylaxis is widely used.

Methods
We performed a single-center, retrospective case series of HSCT recipients from January 1, 2012 to December 31, 2018. Subjects had clinical symptoms and radiographic evidence for PJP along with at least one positive Pneumocystis test obtained from bronchoalveolar lavage (BAL) including direct fluorescence antibody (DFA), quantitative polymerase chain reaction (qPCR), cytology, and pathology.

Results
1111 subjects underwent HSCT; of whom, 25 (2.2%) met inclusion criteria and were treated for PJP. 6 were autologous and 19 were allogeneic HSCT recipients (1.23% and 3.05% of total autologous and allogeneic HSCT, respectively). All allogeneic HSCT recipients received in-vivo T-cell depletion. Median duration from autologous and allogeneic HSCT to PJP diagnosis were 138 days (range 20 to 348) and 346 days (range 41 to 771), respectively. PJP qPCR was positive in all samples tested (n = 20, range < 84 to 14900). DFA was positive in 6 (28%). Death from pneumonia occurred in 2 subjects; 11 (44%) required ICU stay, and 7 (27%) required intubation. At diagnosis, 3 subjects had relapse of underlying disease and 10 were on immunosuppression. 12 were on PJP prophylaxis (autologous HSCT n = 3), the most common of which was atovaquone (n = 5); only 2 subjects were on TMP-SMX. Cytomegalovirus (CMV) viremia was detected in 9 subjects (36%) prior to PJP diagnosis; 4 had pulmonary CMV coinfection. In total, 17 subjects (68%) had one of the above risk factors for PJP. Median total lymphocyte count and % lymphocytes were 5.1 × 103 cells/μL (range 1.4 to 38.5 × 103 cells/μL) and 9.6% (range 1.1 to 29.5%), respectively.

Conclusion
PJP is an uncommon (2.2% of the study population) complication of HSCT while receiving PJP prophylaxis and in the absence of disease relapse, CMV reactivation, or ongoing immunosuppression. Presentation is often delayed in this population; a high degree of clinical suspicion should prompt diagnostic evaluation using a combination of laboratory tests on BAL fluid.

Disclosures
All authors: No reported disclosures.
2699. Pneumococcal Vaccination During Chemotherapy in Children Treated for Acute Lymphoblastic Leukemia
Authors: Dorval Sarah , Coïc Léna , Blais Denis , Leclerc Jean-Marie , Laverdière Caroline , Ovetchkine Philippe , Tapiéro Bruce 
Published: October 2019

Abstract

Background
Children undergoing therapy for acute lymphoblastic leukemia (ALL) are at high risk of invasive pneumococcal disease (IPD). Immunization with conjugated vaccines following chemotherapy is recommended for pediatric patients. In an attempt to provide an earlier protection against invasive pneumococcal infection, we aimed to assess immunity to S. pneumoniae among children vaccinated during chemotherapy for ALL.

Methods
We retrospectively analyzed the rate of seroprotection among ALL children treated in our institution in accordance with the DFCI ALL Consortium protocol between 2007 and 2014. A pneumococcal conjugate vaccine (PCV) booster was given to all subjects after the end of chemotherapy (groups 1 and 2). In group 2, a PCV dose was also administered during the maintenance phase. Clinical characteristics as well as individual immunization records were collected from our local immunization database. All children were up to date with their vaccination schedule at diagnosis. Serum samples were obtained on a routine follow-up visit, after the end of chemotherapy and after the PCV vaccine booster to measure serotype-specific IgG pneumococcal antibodies. Antibody level ≥0.35µg/mL was considered protective. Patients with seroprotective antibodies level for ≥ 50% of serotypes contained in vaccines were defined as seroprotected.

Results
62 children [34 girls (54.8%)] were included in the analysis. Median age at diagnosis was 45 months (range:12–160).
At the end of chemotherapy, 34.2% of children in group 1 (13/38) and 79.2% in group 2 (19/24) were seroprotected (P < 0.01). Median interval of time between the end of chemotherapy and the PCV booster vaccination was 6 months (range: 2–64 months). After PCV-13 booster, the rate of seroprotection raised to 100% (38/38) in group 1 and 91.7% in group 2 (22/24).

Conclusion
Rates of pneumococcal seroprotected children treated for ALL are low at the end of chemotherapy. However, PCV booster during chemotherapy could be useful to increase the level of seroprotection and shorten the period of susceptibility to IPD. After chemotherapy for ALL, children benefit from a PCV booster to enhance seroprotection.

Disclosures
All authors: No reported disclosures.