bluuebunny/crossref_metadata_2025_split huggingface dataset:
163. Infective Endocarditis in Qatar: Risk Factors, Clinical Characteristics, Microbiology, and Outcomes
Authors: Zaqout Ahmed , Mohammed Shaban , Thapur Maliha , Al Soub Hussam , Almaslamani Muna , Al Khal Abdullatif , Omrani Ali S 
Published: October 2019

Abstract

Background
Infective endocarditis (IE) is a serious and life-threatening disease. The aim of the study is to describe the epidemiology, clinical characteristics and outcomes of patients with IE in Qatar.

Methods
Patients were identified from the electronic records of Hamad Medical Corporation hospitals, the national referral center for the State of Qatar. Those aged ≥18 years with Duke Criteria-based diagnosis of IE during the period from January 2015 to September 2017 were included. Data were analyzed using STATA software Version 15.

Results
Fifty-seven cases were included, of which 70% were males. Mean age was 51 years (± 16.8). Eleven (19%) were in association with prosthetic valves and 6 (11%) with implantable cardiac devices (Table 1). Fever (84%), dyspnea (46%) and heart failure were the commonest presentations. The majority of patients had preexisting valvular heart disease or intra-cardiac devices (Table 1). Skin infections (10, 18%) were the most prevalent portals of infection, followed by venous catheters, recent valve surgery and implantable cardiac devices (Table 1). Staphylococcus species were implicated in 19 (34%) and Streptococcaceae in 9 (16%); whereas 21 (37%) were culture-negative (Table 2). Left-side IE (49, 86%) was predominant. Acute kidney injury (AKI) (17, 30%) and heart failure (11, 19%) were common complications. The most frequently used treatment regimens included glycopeptides or Β-lactams (Table 2). Only 9 (16%) patients underwent surgical intervention. Fourteen (25%) patients died of any cause before hospital discharge. Logistic regression analysis identified septic shock and AKI as the only risk factors independently associated with in-hospital mortality (Table 3).

Conclusion
Skin infections are an important risk for IE in Qatar. The majority of patients with IE have preexisting cardiac conditions. Staphylococci are the commonest confirmed bacterial etiology of IE in Qatar, but nearly one-third of cases are culture-negative. Only a small proportion of patients with IE undergo surgical intervention and overall mortality is high. The findings suggest that efforts should be directed toward improving IE prevention strategies in high-risk patients, encourage early microbiological investigations and improved medical and surgical management.

Disclosures
All authors: No reported disclosures.
2710. Novel Analytical Models for Pneumococcal Multiplex Opsonophagocytosis Assay Results from a Healthy Older Adult Population Vaccinated with PCV13
Authors: LaFon David , Kim Young , Nahm Moon H 
Published: October 2019

Abstract

Background
The multiplexed opsonophagocytosis assay (MOPA) measures killing of pneumococci by serum antibodies, and is the primary method for measuring pneumococcal antibodies in adults. However, pre-vaccine opsonic activity and vaccine response are highly variable among serotypes and individuals, and there are currently no criteria to define normal MOPA results.

Methods
We performed post-hoc analysis of data from n = 311 healthy, pneumococcal-vaccine naïve adults aged 55–74 who received 0.5 mL PCV13, and had MOPA performed for PCV13 serotypes (except serotype 3) at baseline, then on days 29 and 181 post-vaccine (Jackson et al. 2018, Vaccine). MOPA results (reported as opsonic index, or OI) were standardized using pneumococcal reference serum 007sp. Pairwise comparisons of proportions of undetectable baseline OI (≤ 4) between serotypes were performed using Pearson’s Chi-square. Immunogenicity (mean change in OI at day 29 post-PCV among samples with undetectable baseline OI) was compared between serotypes using one-way ANOVA. We then assigned a score based on cutoffs for pre-vaccine OI (cutoff 1, or C1) and fold-rise in OI at day 29 (cutoff 2, or C2) for each serotype, as shown in Figure 1. The sum of the scores for 12 serotypes was determined for each participant. We plotted the frequency distribution of total scores using different combinations of values for C1 and C2 to visually identify the optimal fit for the left-skewed distribution expected in a healthy population.

Results
Serotype 1 had the highest prevalence of undetectable OI at baseline (77.0%, P < 0.001), and serotype 19A had the lowest (8.8%, P < 0.001). Immunogenicity was highest for serotype 7F (mean change of 18354, P < 0.001 for all comparisons). For vaccine response analysis, C1 = 300 and C2 = 8 produced a left-skewed distribution (Figure 2). Using these cutoffs, the median total score was 7 and the 5th percentile score was −1.

Conclusion
Criteria for normal MOPA results can be developed for single-timepoint data, or using a scoring system for vaccine response data that integrates pre-vaccine OI and fold-rise in OI. Additional studies in healthy and disease populations are needed to further optimize diagnostic criteria for discriminating normal vs. abnormal results.

Disclosures
All authors: No reported disclosures.
164. Analysis of Adult, Hospitalized Patients With Carbapenem-resistant (CR) Gram-Negative Bloodstream Infections (GN-BSIs) due to Lactose Fermenters (LFs) and Non-lactose Fermenters (NLFs): Is There a Difference in Outcomes?
Authors: Lodise Thomas , Kanakamedala Hemanth , Hsu Wei-Chun , Cai Bin 
Published: October 2019

Abstract

Background
The deleterious consequences of BSIs due to CR-GN bacteria among hospitalized adult patients are well described in the literature. However, scant data exist that compares the baseline features and outcomes of patients with CR-GN-BSIs due to LFs relative to those caused by NLFs.

Methods
We performed a retrospective cohort analysis of consecutive hospitalized adult patients (age ≥18 years) in the Premier Healthcare Database (January 2014–June 2018) with GN-BSI due to select LFs (E. coli, Klebsiella spp., Citrobacter spp., Enterobacter spp., and Serratia spp.) and NLFs (Pseudomonas spp., Acinetobacter spp., and Stenotrophomonas spp.). Patients with a diagnosis of cystic fibrosis or who had both LF and NLF GNB on index BSI culture were excluded. Baseline demographics, medical history, comorbidities, hospitalization history, and outcomes were compared between patients with CR-GNB due to LFs and NLFs. Outcomes assessed included composite death (in-hospital death or discharge to hospice), in-hospital mortality, discharge to home, and hospital length of stay post index GNB-BSI culture collection.

Results
Of the 1749 patients with a CR-GNB-BSI due to an LF or NLF, 1505 met study criteria. Of the 1505, 418 (27.8%) were LFs and 1087 (72.2%) were NLFs. The most common LFs were Klebsiella spp. (55.7%) and Enterobacter spp. (25.7%), while Stenotrophomonas spp. (45.2%) was the most common NLF. Overall, groups were highly similar at baseline but patients with CR-GNB-BSIs due to an LF were slightly older and more likely to be in the ICU at index BSI culture collection (table). Outcomes were also comparable between patients with CR-GNB-BSIs due to LFs and NLFs but there were a few notable differences. Composite mortality was higher in patients with GNB-BSIs due to an LF and these patients were also less likely to be discharged home.

Conclusion
The findings indicate that CR-GNB-BSIs result in considerable morbidity and mortality irrespective of whether the GNB is an LF or NLF. One in five patients died during their hospitalization and less than half were discharged home. This highlights the need for better and more preventive and therapeutic strategies aimed at combating CR-GNB-BSIs.

Disclosures
All authors: No reported disclosures.
2714. Streptococcus pneumoniae Nasopharyngeal Carriage in Canadian Adults Hospitalized with Community-Acquired Pneumonia from 2010 to 2017
Authors: LeBlanc Jason J , ElSherif May , Lang Amanda L S , Gillis Hayley D , Ye Lingyun , MacKinnon-Cameron Donna , Ambrose Ardith , Hatchette Todd F , Martin Irene , Demczuk Walter , Andrew Melissa K , Boivin Guy , Bowie William , Green Karen , Johnstone Jennie , Loeb Mark , McCarthy Anne , McGeer Allison , Semret Makeda , Trottier Sylvie , Valiquette Louis , Webster Duncan , McNeil Shelly 
Published: October 2019

Abstract

Background
Streptococcus pneumoniae can colonizes the human nasopharynx, and can cause life-threatening infections like community-acquired pneumonia (CAP) and invasive pneumococcal diseases (IPD). In Canada, the 13-valent conjugate vaccine (PCV13) was introduced in childhood immunization since 2010, with hopes that it would not only protect the vaccinated, but also confer indirect protection to adults through herd immunity. Given data on S. pneumoniae nasopharyngeal (NP) carriage in adults is scarce, this study reports on S. pneumoniae-positivity and serotype distribution in adult carriage from years 2010 to 2017.

Methods
Active surveillance was performed in adults hospitalized with for CAP or IPD from December 2010 to 2017. For assessment of S. pneumoniae carriage, NP swabs were tested using lytA and cpsA real-time PCR. S. pneumoniae-positive NPs were subjected to serotyping using conventional and real-time multiplex PCRs.

Results
Overall, 6472 NP swabs were tested, and Spn was identified in 366 (5.7%). Of the 366 S. pneumoniae-positive NP swabs, a serotype was assigned in 355 (97.0%). From years 2010 to 2017, the proportion of S. pneumoniae-positive NP swabs declined from 8.9% to 4.3%. This was also reflected in the proportion of serotypeable results attributed to PCV13 serotypes, which also declined from 76.9% to 42.2%. The decline was primarily attributed to PCV13 serotypes 7F and 19A. PCV13 serotype 3 remained predominant throughout the study, as did non-PCV13 serotypes like 22F, 33F, and 11A. On the other hand, a proportional rise over time was noted for non-vaccine serotypes (from 15.4% to 31.1%). This was primarily attributed to serotypes 23A, 15A, and 35B.

Conclusion
Monitoring serotype trends is important to assess the impact of pneumococcal vaccines. While herd immunity from PCV13 childhood immunization was anticipated, few studies have assessed its impact on adult carriage. This study described Spn serotype distribution in adults over years 2010 to 2017, demonstrating not only a reduction of PCV13 serotypes over time, but a proportional rise in non-vaccine serotypes. These emerging serotypes may represent the emergence of serotype replacement. Ongoing serotype surveillance will be needed to compare S. pneumoniae carriage to serotypes associated with pneumococcal CAP and IPD.

Disclosures
All authors: No reported disclosures.
2715. Pneumococcal Community-Acquired Pneumonia Attributed to PCV13 Serotypes in Hospitalized Adults: Comparison of the 50–64 and 65+ Age Groups
Authors: LeBlanc Jason J , ElSherif May , Ye Lingyun , MacKinnon-Cameron Donna , Ambrose Ardith , Hatchette Todd F , Lang Amanda L S , Gillis Hayley D , Martin Irene , Demczuk Walter , Andrew Melissa K , Boivin Guy , Bowie William , Green Karen , Johnstone Jennie , Loeb Mark , McCarthy Anne , McGeer Allison , Semret Makeda , Trottier Sylvie , Valiquette Louis , Webster Duncan , McNeil Shelly 
Published: October 2019

Abstract

Background
In healthy adults aged ≥65 years, direct immunization with the 13-valent pneumococcal conjugate vaccine (PCV13) was shown effective at preventing vaccine-type pneumococcal community-acquired pneumonia (pCAP) and invasive pneumococcal disease (IPD). Although PCV13 was licensed for use in Canadian adults aged >50 years, it was recommended for immunocompromised individuals who are at highest risk of IPD. In 2016, a recommendation was issued for use of PCV13 in immunocompetent adults aged ≥65 years, for the prevention of pCAP and IPD. This study aimed to compare pCAP cases attributed to PCV13 serotypes in adults aged 50–64 and ≥65 years.

Methods
Active surveillance for CAP and IPD was performed from 2010 to 2015 in adult hospitals across five Canadian provinces. To identify pCAP, blood culture, sputum culture, or a PCV13 serotype-specific urine antigen detection (ssUAD) were used. Serotype was assigned using Quellung reaction, PCR, or ssUAD. All pCAP cases were categorized by serotype and age groups. Patient demographics and outcome data were collected.

Results
Over years 2010–2015, 6687 CAP cases were tested. 835 pCAP cases were identified, of which 418 (50%) caused by a PCV13 serotype. The majority (74%) of PCV13-associated pCAP occurred in the adults aged ≥50 years, whereas only 41.4% (173/418) were in adults ≥65 years. PCV13 pCAP cases declined over the years, likely through herd immunity from childhood immunization. The yearly proportion of pCAP attributed to PCV13 serotypes for ages ≥50 remained high (67.5 to 80.6%), compared those occurring in the ≥65 age groups (35.1 to 49.4%). Compared with test-negative controls, pCAP cases in both age groups were more likely to be admitted to ICU, require mechanical ventilation, and had higher mortality. Of pCAP deaths, 61.4% and 82.3% were in the ≥65 and ≥50 age cohorts, respectively.

Conclusion
From year 2010 to 2015, adults hospitalized with PCV13 pCAP in the ≥65 age cohort accounted for less than half of the cases, whereas including the 50–64 age cohort increased the proportion to 74%. Similarly, the proportion of PCV13 pCAP deaths that occurred in adults aged ≥50 years was 82%, compared with 61% in the ≥65 age cohort. Expansion of PCV13 recommendations to include adults 50–64 years of age should be considered.

Disclosures
All authors: No reported disclosures.
2719. Immunogenicity and Safety of a Quadrivalent Meningococcal Conjugate Vaccine (MenACYW-TT) Administered in Adults 18–55 Years of Age
Authors: Peterson James , Hedrick James , Pan Judy , Neveu David , Jordanov Emilia , Dhingra Mandeep S 
Published: October 2019

Abstract

Background
The MenACYW-TT conjugate vaccine is a quadrivalent meningococcal vaccine that contains tetanus toxoid as carrier protein. The vaccine is intended for global use in all age groups (i.e., individuals 6 weeks of age and older). This Phase III study evaluated the immune lot consistency, and safety and immunogenicity of the vaccine when compared with a licensed quadrivalent meningococcal conjugate vaccine in individuals 10–55 years of age.

Methods
A randomized, modified double-blind, multi-center study (NCT02842853) was conducted in the United States. The study evaluated 3344 meningococcal vaccine naïve adolescents and adults, who were randomly assigned to receive either a single dose of one of the three lots of MenACYW-TT conjugate vaccine or single dose of Menactra® [MenACWY-D]. Serum bactericidal assay with human complement (hSBA) and rabbit complement (rSBA) was used to measure antibodies against serogroups A, C, W, and Y at baseline before vaccination (Day 0) and 30 days post-vaccination. Safety data were collected up to 6 months post-vaccination. Herein we report the performance of MenACYW-TT in adults 18 through 55 years of age (n = 1,807).

Results
Immune equivalence was demonstrated across all 3 lots of MenACYW-TT conjugate vaccine based on geometric mean titers (GMTs) for all serogroups. Non-inferiority of immune responses, based on percentages of participants achieving hSBA vaccine seroresponse, was demonstrated between MenACYW-TT and MenACWY-D for all four serogroups at Day 30 compared with baseline. The proportions of individuals (18–55 years) with hSBA ≥ 1:8 following MenACYW-TT administration were higher than those after MenACWY-D administration for all four serogroups (A: 93.5% vs. 88.1%; C: 93.5% vs. 77.8%; W: 94.5% vs. 80.2%; Y: 98.6% vs. 81.2%). A similar trend was observed for post vaccination GMTs in adult participants. Reactogenicity profiles were comparable across study groups. Most unsolicited adverse events were of grade 1 or grade 2 intensity. No vaccine-related serious adverse events were reported.

Conclusion
MenACYW-TT vaccine was well tolerated and demonstrated a non-inferior immune response compared with the licensed MenACWY-D vaccine when administered as a single dose to meningococcal vaccine naïve adults.

Disclosures
All authors: No reported disclosures.
2723. Immunogenicity and Safety of a Quadrivalent Meningococcal Conjugate Vaccine (MenACYW-TT) Administered in Adolescents 10–17 Years of Age
Authors: Peterson James , Hedrick James , Pan Judy , Neveu David , Jordanov Emilia , Dhingra Mandeep S 
Published: October 2019

Abstract

Background
The MenACYW-TT conjugate vaccine is a quadrivalent meningococcal vaccine that contains tetanus toxoid as carrier protein. The vaccine is intended for global use in all age groups (i.e., individuals 6 weeks of age and older). This Phase III study evaluated the immune lot consistency, and safety and immunogenicity of the vaccine when compared with a licensed quadrivalent meningococcal conjugate vaccine in individuals 10–55 years of age.

Methods
A randomized, modified double-blind, multi-center study (NCT02842853) was conducted in the United States. The study evaluated 3344 meningococcal vaccine naïve adolescents and adults, who were randomly assigned to receive either a single dose of one of the three lots of MenACYW-TT conjugate vaccine or single dose of Menactra® [MenACWY-D]. Serum bactericidal assay with human complement (hSBA) and baby rabbit complement (rSBA) was used to measure antibodies against serogroups A, C, W and Y at baseline before vaccination (Day 0) and 30 days post-vaccination. Safety data were collected up to 6 months post-vaccination. Herein we report the performance of MenACYW-TT in adolescents 10 through 17 years of age (n = 1504).

Results
Immune equivalence was demonstrated across all 3 lots of MenACYW-TT conjugate vaccine based on geometric mean titers (GMTs) for all serogroups. Non-inferiority of immune responses, based on percentages of participants achieving hSBA vaccine seroresponse, was demonstrated between MenACYW-TT and MenACWY-D for all four serogroups at Day 30 compared with baseline. The proportions of individuals (10–17 years) with hSBA ≥ 1:8 following MenACYW-TT administration were higher than those after MenACWY-D administration for all four serogroups (A: 96.2% vs. 89.0%; C: 98.5% vs. 74.7%; W: 98.3% vs. 93.7%; Y: 99.1% vs. 94.3%). A similar trend was observed for post vaccination GMTs in adolescent participants. Reactogenicity profiles were comparable across study groups. Most unsolicited adverse events were of grade 1 or grade 2 intensity. No vaccine-related serious adverse events were reported.

Conclusion
MenACYW-TT vaccine was well tolerated and demonstrated a non-inferior immune response compared with the licensed MenACWY-D vaccine when administered as a single dose to meningococcal vaccine naïve adolescents.

Disclosures
All authors: No reported disclosures.
2725. Immunogenicity and Safety of a Booster Dose of a Quadrivalent Meningococcal Conjugate Vaccine (MenACYW-TT) in Adolescents and Adults
Authors: Hedrick James , Simon Michael W , Christensen Shane , Anez German , Pan Judy , Jordanov Emilia , Dhingra Mandeep S 
Published: October 2019

Abstract

Background
The MenACYW-TT conjugate vaccine is a quadrivalent meningococcal vaccine that contains tetanus toxoid as carrier protein. Vaccine is intended for global use in all age groups (i.e., individuals 6 weeks of age and older). This Phase III study evaluated the safety and immunogenicity of the vaccine when compared with a licensed quadrivalent meningococcal conjugate vaccine in individuals ≥ 15 years of age.

Methods
A randomized, modified double-blind study (NCT02752906) was conducted in the United States and Puerto Rico. The study evaluated 810 participants primed with a licensed quadrivalent meningococcal conjugate vaccine (Menactra® [MenACWY-D] or MENVEO® [MenACWY-CRM]) in the 4 to 10 years prior to enrollment. Participants were randomly assigned to receive either a single booster dose of MenACYW-TT conjugate vaccine or MenACWY-D. Safety data were collected up to 6 months post-vaccination.

Results
Non-inferiority of immune response was demonstrated for MenACYW-TT vs. MenACWY-D based on percentages of participants achieving an serum bactericidal assay with human complement (hSBA) seroresponse for serogroups A, C, W, and Y at Day 30 post-vaccination. Post-vaccination hSBA geometric mean titers (GMTs) were higher following administration of MenACYW-TT compared with MenACWY-D for age subgroups ≥15 to < 18 years and ≥18 years. Relative to MenACWY-D, post-vaccination hSBA GMTs were higher for all 4 serogroups following administration of MenACYW-TT in participants who received the priming vaccine < 7 years prior to the booster; for participants who received priming vaccine ≥7 years prior to booster, post-vaccination GMTs were higher for serogroups C, W and Y, and comparable for serogroup A. In MenACWY-CRM-primed subjects, hSBA vaccine seroresponse rates were comparable for all 4 serogroups regardless of the booster vaccine administered. In MenACWY-D-primed subjects, hSBA seroresponse rates following MenACYW-TT booster administration were comparable for serogroups A and Y, and higher for serogroups C and W. Reactogenicity profiles were comparable across study groups.

Conclusion
MenACYW-TT conjugate vaccine was immunogenic and well tolerated when administered as a booster dose to individuals ≥15 years of age.

Disclosures
All authors: No reported disclosures.
2731. Does Last Season’s Influenza Vaccination Affect Current Season’s Vaccine Effectiveness in Young Children?
Authors: Rao Suchitra , Lamb Molly , Moss Angela , Asturias Edwin J 
Published: October 2019

Abstract

Background
We evaluated influenza VE over two consecutive years vs. the current season against influenza illness during two H3N2-predominant seasons in children receiving care at emergency/urgent care (ED/UC) facilities in metropolitan Colorado.

Methods
We conducted a test-negative case–control analysis of 1478 children aged 6 months to 8 years enrolled at Children’s Hospital Colorado ED/UC with influenza like illness during the 2016–2017 and 2017–2018 influenza seasons. The primary outcome was PCR-confirmed influenza and vaccination status was confirmed using electronic medical record and parental interviews. Vaccination status was defined as completely vaccinated (all doses of influenza vaccine according to child’s age); partially or not vaccinated children were defined as unvaccinated. Multivariable logistic regression models adjusted for high-risk medical condition, age, race and insurance status were used to calculate odds ratios (OR) and 95% confidence intervals. Vaccine effectiveness was calculated as (1 − OR) × 100.

Results
Of the 1224 (82.8%) children enrolled in the study with known vaccination status for both seasons, 361 (29%) tested positive for influenza. Overall, VE against influenza was 49% (95% CI, 33–61%) after adjusting for other covariates in the model. VE did not differ significantly between those vaccinated in both seasons and those vaccinated in only the current season (VE 69%, 95% CI 41–115) (Table 1).

Conclusion
Our estimates of influenza VE for two predominantly H3N2-influenza seasons in Colorado are comparable to the CDC -VE for children 6 months to 8 years. VE against ED or UC-attended influenza illness in children did not vary significantly by prior seasons’ vaccination status.

Disclosures
All authors: No reported disclosures.