bluuebunny/crossref_metadata_2025_split huggingface dataset:
2585. Identification of Risk Factors for Pseudomonas aeruginosa in Patients with Community-Acquired Pneumonia
Authors: Karajeh Jenna , Sapozhnikov Julia , Adams Jenna , Albarillo Fritzie S , Santarossa Maressa , Hoff Brian M 
Published: November 2023

Abstract

Background
Community-acquired pneumonia (CAP) is a leading infectious cause of hospitalization, morbidity, and mortality worldwide. As the etiology of CAP continues to evolve, antibiotic-resistant bacteria are becoming more prevalent in the community setting. Among these pathogens is Pseudomonas aeruginosa. Although incidence of CAP due to P. aeruginosa is low, it has been linked to severe illness and poor clinical outcomes, highlighting the challenge in treating this infection. Identifying local risk factors for pneumonia due to drug-resistant pathogens, specifically P. aeruginosa, can potentially reduce the overuse of unnecessary empiric broad-spectrum antipseudomonal agents and increase appropriateness of empiric antibiotic treatment regimens.

Methods
A single-center, retrospective cohort study was conducted in patients who were treated for CAP at a large academic medical center from August 1, 2019 through July 31, 2022. Specimen data were reviewed and separated into two groups. The P. aeruginosa group was composed of P. aeruginosa-positive respiratory specimens whereas the non-P. aeruginosa group comprised all other pathogens and specimen-negative results. The primary endpoint was to identify risk factors for P. aeruginosa in patients with CAP at our institution.

Results
A total of 206 patients were screened and 79 of them were included in the analysis (39 P. aeruginosa encounters and 40 non-P. aeruginosa encounters). Baseline characteristics were well-distributed between groups. A univariate analysis determined 13 variables were significant at P &lt; 0.2. This P-value was used for entry into the logistic regression model. Of the 13 variables, four were determined to be correlated most closely with CAP due to P. aeruginosa: chronic pulmonary disease (OR, 12.4 [95% CI, 2.5 to 61]), prior intravenous antibiotics within the last 12 months (OR, 15.7 [95% CI, 3.2 to 77.2]), sputum production (OR, 8.1 [95% CI, 1.6 to 41.3]), and tube feeds at time of admission (OR, 21.2 [95% CI, 1.2 to 360.5]).

Conclusion
Although the study sample size was small, chronic pulmonary disease, prior intravenous antibiotics within the last 12 months, sputum production, and tube feeds at time of admission correlated most closely with CAP due to P. aeruginosa at our institution.

Disclosures
All Authors: No reported disclosures
2588. Burden of Mortality and Antimicrobial Resistance of Bacterial Pathogens Associated with Lower Respiratory Tract and Other Thorax Infection in United States in 2019: A Systematic Analysis
Authors: Mallyala Sahithi Rao , Chirumamilla Avinash , Raj Deepti , Gajjar Jay , Patel Sneh , Dekhne Anushka , Desai Hardik Dineshbhai 
Published: November 2023

Abstract

Background
Detailed information about the impact of bacterial antimicrobial resistance (AMR) on Lower Respiratory Tract and other thorax Infections (LRTIs) is currently unavailable. It is important to have precise data on bacterial AMR to develop effective programs and policies for controlling AMR and to use antibiotics prudently for optimal treatment of LRTI patients. The primary objective of this research is to present extensive estimates of the mortality due to "bacterial pathogens" and its "AMR" of LRTIs in the United States in 2019.

Methods
Mortality data associated with bacterial antimicrobial resistance and lower respiratory tract infection (LRTI) pathogens were acquired from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) in 2019.

Results
In United States, there were 88089 deaths (95% uncertainty interval [UI]: 66909-117145) due to bacterial pathogens in LRIT in 2019. Highest number of deaths observed due to Staphylococcus aureus (34.04%), followed by Streptococcus pneumoniae (18.30%), Pseudomonas aeruginosa (12.48%) in LRTI in 2019. There were 10984 deaths attributed to and 46482 deaths associated with bacterial AMR in LRTI in 2019.

Conclusion
Bacterial pathogens causing LRTIs are a significant cause of mortality in the United States. Moreover, antimicrobial resistance (AMR) among these pathogens has become a growing concern, exacerbating the burden of LRTI-related deaths. The implementation of such measures, along with the promotion of antimicrobial stewardship, can help to mitigate the impact of LRTI-associated deaths and preserve the effectiveness of available antimicrobial agents for the future.

Disclosures
All Authors: No reported disclosures
2599. Impact of Alveolar Neutrophilia on Outcomes in Patients with Suspected Ventilated Hospital-Acquired Bacterial Pneumonia
Authors: Saravolatz Louis , Albin Owen 
Published: November 2023

Abstract

Background
Ventilated hospital-acquired bacterial pneumonia (vHABP) is a major source of morbidity & mortality in hospitalized patients. Clinical risk scores and systemic biomarkers have limited clinical & prognostic utility in vHABP. Alveolar biomarkers—specifically alveolar neutrophilia (AN), the percentage of polymorphonuclear cells (PMN%) present in bronchoalveolar lavage (BAL) fluid—gauge the host inflammatory response directly at the site of infection, offering an attractive but untested predictive risk biomarker in vHABP. We aimed to generate preliminary data exploring AN as a vHABP biomarker.

Methods
We performed a retrospective cohort study of intensive care unit (ICU) patients with vHABP from 2010-2023. vHABP was defined as development of acute hypoxic respiratory failure requiring invasive mechanical ventilation, clinical suspicion of pneumonia by treating teams prompting performance of BAL respiratory culture, and BAL PMN% &gt; 50%. Patient demographic characteristics, comorbidities and acute severity of illness metrics were abstracted via chart review. PMN% values were dichotomized using median split rounded to the nearest PMN% decile ( &gt; or &lt; 80% PMN% in BAL fluid). Study outcomes included ventilator-free days, ICU length of stay and vHABP-directed antibiotic treatment duration within 30 days of vHABP.

Results
44 patients met study inclusion criteria. 30 (68%) had a BAL neutrophil of &gt; 80%. Patients with BAL PMN &gt; 80% had a numerically higher use of tracheostomy and trend towards lower P/F ratio at the time of vHABP diagnosis [Table 1]. BAL PMN &gt; 80% was associated with a 15% decrease in ventilator-free days (p &lt; 0.01) and a 25% longer ICU length of stay (p &lt; 0.01) than those with BAL PMN &lt; 80% [Figure 1]. There was no significant difference in post-BAL vHABP-directed antibiotic duration in patients with and without BAL PMN &gt; 80%.

Conclusion
Though limited by low sample size, this exploratory study suggests AN may be a potentially useful predictive risk biomarker in vHABP. Larger-scale, prospective studies of alveolar biomarkers—including AN—in vHABP are warranted.

Disclosures
Owen Albin, MD, Charles River Laboratories: Advisor/Consultant|Shionogi: Advisor/Consultant
2601. A 14-year retrospective study of pulmonary nocardiosis in AIDS patients, Northeastern Thailand
Authors: thipmontree wilawan , Suputtamongkol Yupin 
Published: November 2023

Abstract

Background
Nocardiosis is an opportunistic infection in immunocompromised individuals, particularly patients with acquired immune deficiency syndrome (AIDS). Clinical manifestations of nocardiosis are wide-ranging but the most common is pneumonia.

Methods
This 14 year retrospective study included Nocardia species infected adult patients (≥15 years) with at least 28 days of treatment follow-up. This study aims to compare clinical manifestations and survival analysis of cultured confirmed pulmonary nocardiosis among AIDS and non-AIDS patients.

Results
From 2009 to 2022, 237 patients had culture confirmed Nocardia species infection, of which 22 were excluded from this study because 13 had cutaneous nocardiosis and nine had pulmonary nocardiosis with follow-up less than 28 days. A total of 215 confirmed pulmonary nocardiosis were recruited to the analysis, 97(45.1%) were HIV-infected and 118 (54.9%) were non-HIV. All HIV-infected patient has CD4 count below 200 cell/mm3 (range 1-198, 1-15%), known as AIDS. Most of them were male with a mean age of 37 (range 15-83) years. One hundred fifty of the 215 (69.7%) patients underwent brain imaging. Sixteen cases (10.7%) had brain abscess. Disseminated nocardiosis (brain abscess, bacteremia, cutaneous abscess) was found in equal proportions in AIDS (15/97, 15.5%) and non-AIDS patients (17/118, 14.4%), while pulmonary nocardiosis with local invasion (empyema thoracis, pericardial effusion) was more common in AIDS (11/97, 11.3%) than non-AIDS patients (9/118, 7.6%). Overall and 28 days mortality were 116 (53.9%) and 88 (40.9%), respectively. In Cox’s proportional hazard analysis, AIDS was the independent factor associated with 28 days mortality in pulmonary nocardiosis (adjusted HR 2.62; 95%CI, 1.38 to 4.98) and those who underwent brain imaging (adjusted HR 2.75; 95%CI, 1.23 to 6.15) after adjusted by sex, age, duration of illness, respiratory failure, shock, multi-lobar pneumonia, disseminated nocardiosis, and combination antibiotic therapy.

Conclusion
Pulmonary nocardiosis is a serious opportunistic infection in AIDS patient and has shown significantly higher mortality than non-AIDS. Therefore, nocardiosis should always be considered as a cause of pneumonia in AIDS patients in order to prompt aggressive treatment.

Disclosures
Yupin Suputtamongkol, MD, Abbott Labs: Grant/Research Support|Abbott Labs: Mahidol University is partner in the Abbott Pandemic Defense Coalition
2606. Epidemiology of invasive pneumococcal disease in adults with and without underlying lung disease in Ontario, Canada
Authors: Zhong Zoe , Shigayeva Altynay , Plevneshi Agron , Martin Irene , Demczuk Walter , Kus Julianne , Baqi Mahin , Chen Danny , Gold Wayne , Lovinsky Reena , Rau Neil , Richardson David , McGeer Allison 
Published: November 2023

Abstract

Background
The advent of enhanced conjugate pneumococcal vaccines for adults has created a need to assess the burden of pneumococcal disease in different populations to support recommendations for vaccination. We assessed the epidemiology of invasive pneumococcal disease (IPD) in adults with underlying lung disease in Ontario, Canada.

Methods
Ontario introduced PCV7 and PCV13 for children in 2007 and 2010, and PCV13 for immunocompromised adults over 50 years in 2014. TIBDN performs population (pop’n)-based surveillance for IPD in a pop’n of ∼4.5 million. Microbiology laboratories serving area residents report sterile site isolates of Streptococcus pneumoniae; annual audits ensure completeness. Isolates are serotyped at the National Microbiology Laboratory. Population data are from Statistics Canada, with estimates of prevalence of underlying conditions from ICES.

Results
From 2014-2022, 2769 episodes of IPD occurred in adults; detailed clinical data are available for 2366 (85%), and serotyped isolates for 88%. Of these, 573 (24%) had no chronic underlying illness (undill); 1155 (49%) had an undill not affecting the lungs, 165 (7%) had asthma only, 409 (17%) had COPD (with/without asthma or other lung disease (OLD), 64 (2.7%) had OLD alone (most commonly ILD or bronchiectasis). Among those with asthma, 87 (53%) had another undill predisposing to IPD; compared to 290 (71%) of those with COPD and 45 (70%) of those with OLD. Persons with asthma were younger (median age 56y) than those with no or other undill (64y and 61y), and those with COPD or OLD (70 and 71y). Persons with lung disease were more likely to present with bacteremic pneumonia and less likely to have primary bacteremia or meningitis that those without or with other chrill. ICU admission and case fatality rates are in Table 1. The distribution of serotypes causing disease by conjugate vaccine types did not differ among those with lung disease and others (Figure 1). The incidence of disease in persons with asthma and COPD by age group is shown in Figure 2.

Conclusion
The epidemiology of IPD differs somewhat in persons with lung disease compared to others, but conditions other than lung disease have a greater impact on incidence and outcome of IPD in adults. Enhanced PCVs likely provide cost-effective protection for 50-64 year olds with asthma/COPD.

Disclosures
All Authors: No reported disclosures
2620. Normalization of eosinophil count is predictive of reduced oxygen requirement during Covid-19 infection
Authors: Davido Benjamin , Jaffal Karim , Vaugier Isabelle , Bourlet Stephane , De Truchis Pierre , Annane Djillali 
Published: November 2023

Abstract

Background
The initial need for oxygen during Covid-19 has been correlated with the severity of lung involvement observed on CT-scan caused by the cytokine storm. A recent study showed that the normalization of eosinophil count (≥100/mm3) after 48 hours of appropriate regimen was related to a favorable outcome in sepsis. Our work intends to assess the kinetics of eosinophil count over time based on oxygen levels during the acute phase of this viral infection.

Methods
Retrospective study, conducted between March-April 2020 (first wave), among adults admitted directly to a medicine ward. Biological abnormalities, including lymphocyte count, eosinophil count, and CRP were gathered daily during the first week of admission (day 0) according to oxygen level. In case of worsening requiring ICU, oxygen level was censored at 15 L/min. Aim of the study was to investigate whether normalization of eosinophil count could predict a decrease in oxygen requirements, and potentially patient’s outcome. Values were presented as median with 95% CI and statistical analysis utilized the Chi-2 square test.

Results
132 patients were admitted, mean age 59.0±16.3 years. Mean onset of symptoms was 7±4 days. Majority of patients had cardiovascular disease (43.1%), underlying respiratory disease (16.7%), diabetes (18.9%), immunosuppression (8.3%) and obesity (10.6%).
At admission, median (IQR) CRP=79(26-130) mg/L, lymphocyte count=1005(730-1380)/mm3 and eosinophil count=10(0-60)/mm3. 72% of patients required oxygen supply. Lung CT-scan (n=103) revealed: 53.5% had moderate (25-50%) to severe ( &gt;50%) involvement.
Twenty-seven patients (20.5%) required ICU due to condition worsening.
Eosinophil count increased continuously until normalization from day0 to day3, while the oxygen level started to decrease on day 3 without any rebound observed thereafter (Figure 1). Similarly, CRP decreased to 43 mg/L on day2, but ultimately increased again. Patients requiring &lt; 2L/min of oxygen were significantly associated with an eosinophil count≥100/mm3 on day 2 OR=0.2 [0.07-0.56] (p=0.002).

Conclusion
Normalization of eosinophil count over time seems predictive of a decrease of oxygen requirement during Covid-19. Those data should be confirmed on other type of respiratory tract infections.

Disclosures
All Authors: No reported disclosures
2628. Prevalence of respiratory symptoms in children and staff in Pre-K—12th grade schools and subsequent results from respiratory virus testing
Authors: Goldman Jennifer , Schuster Jennifer E , Selvarangan Rangaraj , Almendares Olivia , Sleweon Sadia , Kirking Hannah L , Lee Brian R 
Published: November 2023

Abstract

Background
Little is known about the prevalence of respiratory symptoms and associated respiratory virus detection in students/ staff in primary and secondary schools.

Methods
School KIDS is a prospective respiratory viral surveillance program in a large Missouri school district. Participating students/ staff complete a monthly electronic symptom survey that asks about respiratory symptoms (sx) in the preceding 7 days; participants are categorized based on the presence of any respiratory sx: ongoing (current), resolved, and no sx. Within 36 hours of survey completion, participants undergo surveillance respiratory viral testing at school. Self-administered nasal swabs are tested via multipathogen PCR assay (Table). Prevalence of respiratory viruses in participants with and without sx were calculated. A mixed-effect multivariable logistic regression model was used to compare odds of a sample testing positive based on surveillance sx and enrollee age.

Results
A total of 544 students (30 pre-kindergarten (preK), 320 elementary, 117 middle, and 77 high) and 224 staff enrolled. A total of 2,537 sx surveys with corresponding respiratory samples were collected from November 2, 2022–April 15, 2023 (Table). Of the samples provided, 1,138 were preK-elementary (45%), 368 middle (14%), 276 high (11%), and 755 staff (30%). Participants reported ongoing (20%), resolved (14%), and no sx (66%). Prevalence of commonly reported sx were congestion (21%), runny nose (17%), cough (16%), and fever (3%). Overall respiratory virus test positivity was 26%; 50% of positive samples came from participants without sx. Flu A, PIV, and RSV were more frequently detected in those with ongoing sx. AdV, HMPV, RV/EV, and SARS-CoV-2 were more frequently detected in those with no sx. Increased odds of a positive test were observed among enrollees who reported runny nose (adjusted OR 1.4 [CI 1.0, 1.8]), congestion (adjusted OR 2.2 [CI1.6, 2.8]), cough (adjusted OR 1.5 [CI 1.1, 1.9]), or sore throat (adjusted OR 1.5 [CI 1.1, 2.0]) but not fever (adjusted OR 1.1 [CI 0.7,1.8]).

Conclusion
More research is needed to understand if students with respiratory sx are more likely than asymptomatic students to shed transmissible respiratory viruses.

Disclosures
Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, FAAM, Abbott: Honoraria|Altona Diagnostics: Grant/Research Support|Baebies Inc: Advisor/Consultant|BioMerieux: Advisor/Consultant|BioMerieux: Grant/Research Support|Bio-Rad: Grant/Research Support|Cepheid: Grant/Research Support|GSK: Advisor/Consultant|Hologic: Grant/Research Support|Lab Simply: Advisor/Consultant|Luminex: Grant/Research Support
2633. Nasal Colonization Status of Respiratory Viruses in Patients During the COVID-19 Epidemic Period at a Tertiary Hospital in Japan
Authors: Katsuta Tomohiro , Niiya Ryo , Nakamura Yukitsugu , Shimizu Naoki 
Published: November 2023

Abstract

Background
Few reports have comprehensively investigated the frequency of respiratory virus nasal colonization in both children and adults. Since the coronavirus disease 2019 (COVID-19) pandemic in 2020, St. Marianna University Hospital has used the multiplex polymerase chain reaction (PCR) test (FirmArray® RP2.1 Panel) to diagnose symptomatic patients and admission screening of asymptomatic patients. Thus, we have obtained comprehensive multiplex PCR test results and analyzed the nasal colonization status of respiratory viruses in patients during the COVID-19 epidemic period.

Methods
We conducted a retrospective analysis of the nasal colonization status of respiratory viruses in patients during the COVID-19 epidemic period at St. Marianna University Hospital in Japan, a tertiary hospital with 1,175 beds, including 90 beds for pediatric patients. The results of multiplex PCR tests from August 2020 to January 2023 were analyzed.

Results
A total of 15,107 patients were included in this survey. The patient age groups were &lt; 20 years (1,788, 11.8%), 20–59 years (4,399, 29.1%), and ≥60 years (8,920, 59.1%). The positivity rates for severe acute respiratory syndrome coronavirus 2 were 14.8%, 10.2%, and 6.0%, respectively; rhinovirus or enterovirus 26.2%, 1.9%, and 0.7%, respectively; respiratory syncytial virus 7.1%, 0.4%, and 0.3%, respectively; parainfluenza virus type 3 3.6%, 0.3%, and 0.2%, respectively; and adenovirus 3.1%, 0.3%, and 0.1%, respectively, were detected significantly in children, and to some extent in adults.

Conclusion
Despite various restrictions during the COVID-19 pandemic period, children as well as adults had a certain degree of respiratory virus colonization in the nasal cavity. This result suggests that asymptomatic or mildly symptomatic adults may be spreaders of some viral infections to children.

Disclosures
All Authors: No reported disclosures
2636. Discovery of Spike Identification (SpiID) Nanobody Panel for SARS-CoV-2 Vaccine Development
Authors: Li Qi , Doering Jennifer , Ma Zepei , Mantis Nicholas , Cavacini Lisa , Wang Yang 
Published: November 2023

Abstract

Background
SARS-CoV-2 variants of concern (VoC), particularly the Omicron lineage, are spreading rapidly throughout the world even among vaccinated populations. Unfortunately, the first-generation vaccines and monoclonal antibody therapeutics have significantly reduced efficacy against new variants, creating a need for multivalent next-generation countermeasures, including spike protein-based subunit vaccines.

Methods
Although spike protein-based subunit vaccines are relatively easy and cost-effective to manufacture, the challenges present when it comes to Chemistry, Manufacturing, and Controls (CMC) from a clinical perspective. Specifically, multivalent and/or combination subunit vaccines of different variants require specific identity testing with analytical assay reagents which can distinguish closely related antigens. In order to overcome this difficulty, a panel of SARS-CoV-2 VoC-specific nanobodies was developed from a diverse synthetic yeast-display library.

Results
These nanobodies, when expressed with human IgG-Fc fragments as fusion antibodies, showed high specificity against individual variants with nanomolar range affinity (8.1- 68nM) against various VoCs, including Wuhan, Beta, Delta, and Omicron with no cross-reactivity with other variants. Additionally, a subset of nanobodies demonstrated potent virus-neutralizing activity in vitro in the sub-nanomolar range (0.1-0.8nM), and may be useful as biological standards in clinical settings.

Conclusion
These findings offer potential CMC solutions for developing multivalent and/or combination subunit vaccines against newly emerged SARS-CoV-2 variants, improving clinical outcomes for patients.

Disclosures
All Authors: No reported disclosures