bluuebunny/crossref_metadata_2025_split huggingface dataset:
991. Randomized Trial of High Dose, Adjuvanted, and Standard Inactivated Influenza Vaccine Immune Response Against Egg- and Cell-Propagated Vaccine Strains in Older Adults, 2016–2017 Season
Authors: McLean Huong , Levine Min , King Jennifer , Spencer Sarah , Flannery Brendan , Belongia Edward 
Published: November 2018

Abstract

Background
High dose (HD-IIV), standard dose (SD-IIV), and MF-59 adjuvanted (aIIV) influenza vaccines are licensed for adults ≥65 years old, but there is no preferential recommendation for a specific product. These vaccines are manufactured using egg-adapted high growth reassortant viruses. Recent data suggest that antibodies generated by egg-adapted A(H3N2) viruses may contribute to reduced vaccine effectiveness. We report results from the first year of a 2-year randomized trial of vaccine immunogenicity, including response to A(H3N2) vaccine strains propagated in egg (H3N2-egg) and cell culture (H3N2-cell).

Methods
Adults 65–74 years old were randomized to receive 2016–2017 trivalent inactivated influenza vaccines: SD-IIV (n = 60), HD-IIV (n = 59), and aIIV (n = 60). Pre- and post-vaccination sera were analyzed by microneutralization assays (MN) to egg- and cell-propagated A(H3N2) vaccine virus, A/Hong Kong/4801/2014 and tested by hemagglutination inhibition (HI) assays to A/California/7/2009 A(H1N1)pdm09-like and B/Brisbane/60/2008-like viruses. Endpoints were postvaccination geometric mean titer (GMT), mean fold rise (MFR), and seroconversion. Respiratory swabs from adults with acute respiratory illness during the season were tested by RT-PCR to identify vaccine failures.

Results
Prevaccination MN and HI titers were similar across study arms. There were no differences across study arms in postvaccination MN GMT, seroconversion, and MFR against H3N2-egg and H3N2-cell (figure). However, response was lower against H3N2-cell than H3N2-egg. HI MFR for H1N1pdm09 and B/Brisbane were significantly higher in HD-IIV than SD-IIV and aIIV recipients (figure). Eight participants had PCR-confirmed A(H3N2) infection: 1/60 (2%) SD-IIV, 4/57 (7%) HD-IIV, and 3/60 (5%) aIIV recipients. Postvaccination H3N2-cell MN GMT was 15 and 63, respectively for A(H3N2) cases and noncases. Among the eight A(H3N2) cases, postvaccination MN titers were ≥1:40 against H3N2-egg for 6 cases vs. 0 cases against H3N2-cell.

Conclusion
Postvaccination MN titers against H3N2 egg- and cell-propagated vaccine viruses were similar across study arms, although antibody response was lower to H3N2-cell. HD-IIV generated greater antibody response against A(H1N1)pdm09 and B compared with SD-IIV or aIIV.

Disclosures
All authors: No reported disclosures.
995. Effectiveness of Influenza Vaccine for Prevention of Influenza-Associated Hospitalizations Among High-Risk Adults in the United States, 2015–2016
Authors: Alyanak Elif , Gaglani Manjusha , Martin Emily T , Monto Arnold S , Middleton Don , Silveira Fernanda P , Zimmerman Richard , Talbot H Keipp , Ferdinands Jill M 
Published: November 2018

Abstract

Background
Individuals with cardiopulmonary and other chronic conditions are at increased risk for severe complications of influenza. Few studies have examined influenza vaccine effectiveness (VE) in high-risk groups. We evaluated VE against influenza-associated hospitalization among adults with specific high-risk conditions.

Methods
Adults hospitalized with acute respiratory illness (ARI) during the 2015–2016 influenza season were enrolled at eight hospitals participating in the US Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN) study. Respiratory specimens were tested for influenza by reverse transcription PCR. Measures of illness severity, underlying health status, and vaccination were obtained from medical records and enrollment interviews. The presence of high-risk conditions was determined from clinical codes assigned to prior year medical encounters. We estimated VE using a test-negative design as (1 − adjusted odds ratio), comparing odds of PCR-confirmed influenza among vaccinated patients vs. unvaccinated controls. Multivariate logistic regression was adjusted for age, sex, and other factors, stratifying by chronic conditions.

Results
Of 1,467 adults hospitalized with ARI, 236 (16%) had PCR-confirmed influenza; 180 (78%) were A(H1N1)pdm09. In all, 1,358 (93%) had ≥1 high-risk medical condition, and 1,026 (70%) had ≥3 conditions. Cardiovascular (n = 835), metabolic (including diabetes) (n = 773) and lung conditions (n = 692) were most common (figure). Patients with ≥1 high-risk conditions were more likely to be vaccinated (70%) vs. patients not at high risk (31%, P &lt; 0.001). Among all patients, VE against any influenza-associated hospitalization was 50% (95% CI: 31–63). VE was similarly high among patients with neurologic (VE = 64%, 95% CI: 26–83), metabolic (VE = 55%, 95% CI: 30–71), and cardiovascular (VE = 53%, 95% CI: 27–69) conditions, though lower for patients with immunosuppression and malignancy (VE = 20%, 95% CI: −42–54).

Conclusion
Vaccination significantly reduced risk of influenza hospitalization among adults with the most prevalent high-risk cardiovascular, metabolic, and lung conditions. Results support the benefit of vaccinating adults with existing specific chronic conditions.

Disclosures
H. K. Talbot, sanofi pasteur: Investigator, Research grant. Gilead: Investigator, Research grant. MedImmune: Investigator, Research grant. Vaxinnate: Safety Board, none. Seqirus: Safety Board, none.
998. Missclassification of Community and Hospital Onset Bloodstream Infections Using Laboratory-Identified Events
Authors: Khatib Riad , Sharma Mamta , Fakih Mohamad G , Riederer Kathleen , Johnson Leonard 
Published: November 2018

Abstract

Background
Laboratory-identified bloodstream infections (LAB-ID-BSI) are classified as community onset (CO) if blood culture (BC) is collected within 3 days after facility admission and hospital onset if ≥4 days. This classification is often based on a computer-generated subtraction of the day of admission from day of onset. This method may miss recent prior hospitalizations at the same or different facilities.

Methods
We reviewed BC results (January 1, 2010–December 31, 2016), selected patients with BSI and defined the place of onset as CO (day 0–3) and HO (≥4 days) of admission based on LABID-BSI. All patients with CO were further evaluated to determine whether they were recently hospitalized. The source and microbiology of patients with hospitalization within 14 days of the onset of BSI was compared with HO and CO without prior admission within 6 months.

Results
We encountered 5,179 BSI episodes, 3866 (74.6%) were CO. Prior hospitalization in any hospital within 1–14 and 15–180 days of onset was documented in 659 (17.0%) and 1,465 (37.9%), respectively. Source of bacteremia and type of organisms in patients with prior hospitalization within 1–14 days were closer to HO than patients without prior hospitalization with higher frequency of Intravenous catheters (IVC), polymicrobial bacteremia, and candidemia (table).

Conclusion
Using Lab-ID events to classify BSI, one in six patients may risk being misclassified as CO. This underestimates BSI related to hospital setting. Onset classification should be based on thorough historical information and not a computer-generated subtraction of admission and Lab event dates.
Infective endocarditis; soft tissue/bone; pneumonia; abdomen; unknown/miscellaneous; polymicrobial. Gram-positive; Gram-negative; anaerobes; Candida spp. a: P &lt; 0.01; chi square test.

Disclosures
All authors: No reported disclosures.
1002. Epidemiology of Pneumococcal Bacteremia in a Large Tertiary Center
Authors: Asis Aristotle , Gutierrez-Asis Esmeralda , Hassoun Ali 
Published: November 2018

Abstract

Background
Streptococcus pneumoniae remains an important cause of bacteremia in the United States with high morbidity and mortality despite readily available treatment and vaccines. Increased incidence of bacteremia observed during 2017–2018 season.

Methods
Retrospective chart review of patients admitted with pneumococcal bacteremia over the last two winter seasons. Demographics, laboratory data, ICU stay, need for ventilation or pressor, comorbidities, and mortality were collected.

Results
Fifty-three patients enrolled. 62% admitted during 2017–2018. Sixty-six percent white, 60% male, mean BMI 27 (38% had normal BMI). Mean age was 55 years (1–93) (57% &gt; 61). Mean hospital length of stay was 7.8 days (1–30). More than 40% required ICU stay. The use of NPPV, vasopressors, and mechanical ventilation were 6%, 15%, and 17%, respectively. Most common presentation: dyspnea 30% and fever 18%. Smoking history (55%). Eighty percent of these patients had pneumonia. Resistance to penicillin 9% and intermediate susceptibility 6%. Resistance to erythromycin 44% and trimethoprim-sulfamethoxazole 12% which increased during winter 2017 (52% and 12%) compared with winter 2016 (30% and 10%). Only 2% of patients with pneumonia had positive sputum culture for pneumococcus and 62% had positive serum pneumococcal antigen with bacteremia. Positive co-detection of bacterial or viral targets in sputum using Multiplex PCR did not correlate with mortality and hospital stay but they were more likely needed ICU stay, use of vasopressor and mechanical ventilation. 43% of empiric therapy was as recommended by IDSA guidelines. Comparing 2016 vs. 2017 seasons, mortality (15% vs. 6%), hospital stay (9 days vs. 7 days), use of NPPV (5% vs. 6%) mechanical ventilation (15% vs. 18%) and vasopressor (5% vs. 21%). No correlation between influenza infection and bacteremia. Overall 6-month mortality and re-admission rate was 9% and 2%, respectively. Mortality was higher in overweight patients (60% vs. 20%), non-smokers (40% vs. 20%), coronary artery disease (40%) and congestive heart failure (40%).

Conclusion
Pneumococcal bacteremia cause significant morbidity and mortality, we observed less mortality and hospital stay, but more use of NPPV, mechanical ventilation, and vasopressor during 2017–2018 season which had widespread influenza like activity.

Disclosures
All authors: No reported disclosures.
1008. Cluster Analysis to Define Distinct Clinical Phenotypes Among Septic Patients With Bloodstream Infections
Authors: Guillamet M Cristina Vazquez , Bernauer Michael , Micek Scott , Kollef Marin 
Published: November 2018

Abstract

Background
Prior attempts at identifying outcome determinants associated with bloodstream infection have employed a priori determined classification schemes based on readily identifiable microbiology, infection site, and patient characteristics. We hypothesized that even amongst this heterogeneous population, clinically relevant groupings can be described that transcend old a priori classifications.

Methods
Cluster analysis was applied to variables from three domains: patient characteristics, acuity of illness/clinical presentation, and infection characteristics.

Results
Among 3,715 patients with bloodstream infections from Barnes-Jewish Hospital (2008 to 2015), the most stable cluster arrangement occurred with the formation of four clusters. This clustering arrangement resulted in an approximately uniform distribution of the population: Clusters One (21.5%), Two (27.9%), Three (28.7%), and Four (21.9%). Staphylococcus aureus distributed primarily to Clusters Three (40%) and Four (25%), while Enterobacteriaceae were divided predominantly into Clusters Two (34%), Three (30%), and Four (22%). Nonfermenting Gram-negative bacilli grouped mainly in Clusters Four and Two (30% and 31%). More than half of the pneumonia cases occurred in Cluster Four. Clusters One and Two contained 33% and 31%, respectively, of the individuals receiving inappropriate antibiotic administration. Mortality was greatest for Cluster Four (33.8%, 27.4%, 19.2%, 44.6%; P &lt; 0.001), while Cluster One patients were most likely to be discharged to a nursing home.

Conclusion
Our results support the potential for machine learning methods to identify homogenous groupings in infectious diseases that transcend old a priori classifications. These methods may allow new clinical phenotypes to be identified potentially improving the severity staging and treatment of complex infectious diseases.

Disclosures
All authors: No reported disclosures.
1009. Venous 1: A Prospective Multicenter Cohort Study of Enterococcal Bacteremia
Authors: Contreras German , Munita Jose M , Reyes Katherine C , Sahasrabhojane Pranoti , Misikir Helina , Garza Heather , Zervos Marcus J , Aitken Samuel L , Shelburne Samuel A , Arias Cesar 
Published: November 2018

Abstract

Background
Enterococci often cause hospital-associated bloodstream infections in critically ill and immunocompromised patients. Prospective studies to assess the clinical impact of enterococcal bacteremia (EB) are lacking. We conducted a prospective study to investigate the clinical and microbiological factors associated with mortality in EB.

Methods
Adults with EB were prospectively followed in three US tertiary hospitals from September 2016 to March 2018. Individuals with EB for whom follow-up blood culture data within 7 days of index culture were available were included. Microbiologic failure (MF) was defined as clearance of bacteremia ≥4 days after the first blood culture. The main outcome was hospital mortality.

Results
A total of 282 patients were included with 69 (24%) infected with vancomycin-resistant enterococci (VRE). The majority of patients were male (60%) with a median age of 63 years. Median length of hospitalization for VRE patients was longer (25 d) than non-VRE (13 days, P &lt; 0.001). E. faecium corresponded to 77% of VRE isolates, whereas E. faecalis comprised 72% of non-VRE. The average time to first blood culture was 16 days for VRE vs. 4 days for non-VRE (P &lt; 0.001). Patients with VRE were more likely to have hematological malignancy or bone marrow transplant (P &lt; 0.003), whereas patients infected non-VRE were more likely to have solid tumors (P = 0.02). The most common antibiotic used was daptomycin as monotherapy for both VRE and non-VRE with a median dose of 8 mg/kg for both groups. Overall mortality was 25% (43% vs. 20% in VRE vs. non-VRE patients, respectively; P &lt; 0.0001). Factors significantly associated with mortality in univariate analyses included ICU admission, prolonged hospitalization, hematological malignancy, use of immunosuppressive therapy, hemodialysis, neutropenia (&lt;500 cell/mL), Pitt bacteremia score &gt;3, infection with VRE and MF. ICU admission (RR 3.3; 95% CI 1.7–7.5, neutropenia (RR 4.1; 95% CI 1.3–12.9), Pitt bacteremia score &gt;3 (RR 6.8; 95% CI 2.6–18.0), MF (RR 4.7; 95% CI 2.2–10.3) and infection with VRE (RR 4.1; 95% CI 1.1–16.6) remained significantly associated with mortality in multivariate analyses.

Conclusion
The presence of VRE in EB and MF are associated with increased mortality. EB represent a major burden of disease in hospital settings.

Disclosures
C. Arias, Merck & Co., Inc.: Grant Investigator, Research support. MeMed: Grant Investigator, Research support. Allergan: Grant Investigator, Research support.
1012. Group B Streptococcus Bacteremia in Non-Pregnant Adults in a Tertiary Care Hospital Between 2008 and 2017 in Korea
Authors: Lee Jeong Eun , Lee Sun Hee , Lee Shinwon , Kim Kye-Hyung , Lee Soon Ok , Sim YongKi 
Published: November 2018

Abstract

Background
Group B streptococcus (GBS) has emerged as an important cause of invasive infection in nonpregnant adults. This study aimed to describe the clinical characteristics and risk factors associated with GBS bacteremia in nonpregnant adult patients in Korea.

Methods
Our retrospective study reviews the hospital records of nonpregnant adults, aged ≥18 years, with GBS bacteremia who attended the Pusan National University Hospital between January 1, 2008 and December 31, 2017. The presence of underlying diseases, such as cardiovascular diseases, diabetes mellitus, malignancy, liver disease and/or alcohol abuse and renal disease, as well as possible portals of entry of infection, was analyzed.

Results
During the period of 10 years, there were 79 patients with GBS bacteremia. In 47 episodes (59.5%), patients were aged 60 years or older and 43 (54.4%) episodes occurred in females. Their mean age was 61 years (range, 19–91 years) and 70 patients (88.6%) had underlying diseases. Cardiovascular diseases (n = 35, 44.3%) were the most common underlying conditions, and diabetes mellitus (n = 27, 34.2%) and nonhematologic malignancy (n = 27, 34.2%) were second. Genitourinary cancer composed nearly half of nonhematologic malignancy (n = 13, 48.1%). The other comorbid conditions were liver disease and/or alcohol abuse (n = 14, 17.7%), renal disease (n = 13, 16.5%) and hematologic malignancy (n = 7, 8.9%). The most common clinical syndrome was primary bacteremia (n = 31, 39.2%). The others were bone and joint infection (n = 15, 19.0%), urinary tract infection (n = 12, 15.2%), skin and soft-tissue infection (n = 7, 8.9%), infective endocarditis (n = 4, 5.1%), peritonitis (n = 4, 5.1%), and meningitis (n = 2, 2.5%). The overall mortality rate was 13.9%, all patients had at least one underlying disease. The mortality rate of primary bacteremia was significantly higher than those of bacteremia with focus (29.0% vs. 4.2%, respectively; P = 0.002). Hematologic malignancy, liver disease, and/or alcohol abuse and renal disease were significantly associated with the primary bacteremia.

Conclusion
GBS bacteremia is a significant problem in nonpregnant patients, especially primary bacteremia resulted in a high rate of mortality (29%). Hematologic malignancy, liver disease, and/or alcohol abuse and renal disease were significantly related to primary bacteremia occurrence.

Disclosures
All authors: No reported disclosures.
1014. Microbiology and Outcome of Bloodstream Infections in Children With Intestinal Failure
Authors: Seddik Talal , Maldonado Yvonne , Nespor Colleen , Kerner John , Gans Hayley 
Published: November 2018

Abstract

Background
Children with intestinal failure (IF) represent 20% of bloodstream infection (BSI) pediatric hospitalizations. We studied the microbiology and associated outcomes of this population.

Methods
Retrospective cohort study of children ≤18 years with IF dependent on parenteral nutrition (PN), with ≥1 BSI from January 2007 to December 2016. Organisms causing BSI were divided into skin or GI bacteria and fungi based on human habitat and kingdom. The impact of ethanol lock therapy (ELT) and clinical diagnosis of small intestine bacterial overgrowth (SIBO) on the type of these organisms was evaluated. Antimicrobial utilization and outcome measures for BSI were collected.

Results
There were 254 BSIs in 54 children resulting from GI bacteria (58%), skin bacteria (39%), and fungi (16%) with 11% containing &gt;1 group. The proportion of skin bacteria was significantly higher on ELT (27% off vs. 45% on ELT; P = 0.003), while the proportion of GI bacteria was lower (67% off vs. 52% on ELT; P = 0.018). Significantly more fungal BSIs were seen in older children: mean age 4.2 years (95% CI: 2.9–5.5) vs. 2.7 years (95% CI: 2.3–3) with other organisms; P = 0.014. Fungal BSIs were more common with SIBO (18% vs. 5% with and without SIBO; P = 0.013). Twenty-eight organisms were resistant to ceftazidime, and five to cefepime. Hospitalization days totaled 2,432 (median 8 days), with 21 pediatric critical care admissions totaling 156 days. There were six deaths, none related to BSI, 18/54 children were weaned off PN, and four had liver and intestinal transplants. Median course of antimicrobial therapy was 14 days.

Conclusion
The majority BSIs in children resulted from GI bacteria, suggesting intestinal translocation; these infections were not less common in older children despite increased intestinal mass, signifying continued translocation. BSI with GI organisms was not more common in children with SIBO despite increased intestinal bacterial load, possibly due to antibiotic suppressive therapy, which instead lead to more fungal BSIs. Prevention of BSI by ELT was less effective for skin bacteria which may require different regimens or strategies. BSI causes frequent and prolonged hospitalizations including need for intensive care, but deaths are rare.

Disclosures
All authors: No reported disclosures.
1021. Repeat Infective Endocarditis (rIE) in Persons Who Inject Drugs (PWID)
Authors: Huang Glen , Barnes Erin , Peacock James 
Published: November 2018

Abstract

Background
Injection drug use (IDU) is a major risk factor for infective endocarditis (IE). Rates of IE have recently increased in the US concurrent with the opioid crisis. Although IDU-related IE is well described, few data exist on repeat IE (rIE) in persons who inject drugs (PWID).

Methods
Patients ≥18 years old seen at Wake Forest Baptist Medical Center from 2004–2017 with an ICD-9 or -10 diagnosis of IE who met Duke criteria for IE and who self-reported IDU in the 3 months prior to admission were identified. The subset of PWID who developed rIE, defined as another episode of IE at least 10 weeks after the diagnosis of the first episode, was then reviewed.

Results
Of the 94 PWID with IE, 22 (23.4%) experienced rIE (19 re-infections, three relapses). All patients were Caucasian, 50% were male, and 68.2% lived in rural areas; the median age was 30. All 22 patients resumed IDU after their first episode of IE. The mean duration from completion of antibiotics for the prior IE episode to admission with rIE was 257.5 days; the episode of rIE occurred within 1 year in 17 patients (77.3%). On repeat admission, those with rIE had a Pitt bacteremia score of 3.0 and an APACHE II score of 13.1. Fever and bacteremia persisted for an average of 5.6 days and 2.6 days, respectively. S. aureus was the cause of rIE in 54.5% of patients and the tricuspid valve (TV) was involved in 77.3% of cases. Valve surgery occurred in 22.7% of patients. Mean length of stay was 25.3 days and mean duration of antibiotic therapy was 32.1 days. Seven patients (31.8%) died during the rIE hospitalization and another died within 12 months after discharge resulting in a 1-year mortality of 36.3%. Compared with their first episode of IE, rIE patients had higher admission Pitt bacteremia (3.0 vs. 1.5, P = 0.07) and APACHE II scores (13.1 vs. 9.5, P = 0.18), fewer S. aureus infections (54.5% vs. 95.4%, P = 0.01), similar TV involvement (77.3% vs. 72.7%, P = 1), and less frequent surgery (22.7% vs. 59.1%, P = 0.06).

Conclusion
rIE is common in PWID with most episodes occurring within 1 year of the initial episode. Reinfection is more frequent than relapse. The microbiology of rIE is more varied than first episode IE in PWID with S. aureus being less frequently isolated. Illness severity is high, hospitalizations are prolonged, and 1-year mortality is significant. More effective strategies for preventing rIE in PWID are needed.

Disclosures
J. Peacock, Pfizer: Shareholder, Owns common stock in Pfizer which was inherited and held in a trust.