Investigation of Indoor and Outdoor Fine Particulate Matter Concentrations in Schools in Salt Lake City, Utah

Every day around 93% of children under the age of 15 (1.8 billion children) breathe outdoor air that is so polluted it puts their health and development at serious risk. Due to the pandemic, however, ventilation of buildings using outdoor air has become an important safety technique to prevent the spread of COVID-19. With the mounting ev-idence suggesting that air pollution is impactful to human health and educational out-comes, this contradictory guidance may be problematic in schools with higher air pol-lution levels, but keeping kids COVID-19 free and in school to receive their education is now more pressing than ever. To understand if all schools in an urban area are ex-posed to similar outdoor air quality and if school infrastructure protects children equally indoors, we installed research grade sensors to observe PM2.5 concentrations in indoor and outdoor settings to understand how unequal exposure to indoor and out-door air pollution impacts indoor air quality among high- and low-income schools in Salt Lake City, Utah. Based on this approach, we found that during atmospheric inver-sions and dust events, there was a lag ranging between 35 to 73 minutes for the out-door PM2.5 concentrations to follow a similar temporal pattern as the indoor PM2.5. This lag has policy and health implications and may help to explain the rising concerns re-garding reduced educational outcomes related to air pollution in urban areas. These data and resulting analysis show that poor air quality may impact school settings, and the potential implications with respect to environmental inequality.

Mapping Green Infrastructure Based on Multifunctional Ecosystem Services: A Sustainable Planning Framework for Utah’s Wasatch Front

Most sustainable planning frameworks assess natural and social–economic landscape systems as separate entities, and our understanding of the interrelationships between them is incomplete. Landscape classification in urbanizing environments requires an integrated spatial planning approach to better address the United Nation’s sustainable development challenges. The objective of this research is to apply a multicriteria evaluation which ranked diverse ecosystem–service producing landscapes and synthesize the findings within a unique green infrastructure spatial planning framework. Local government stakeholder derived weighting and GIS classification were operated to map both the urban and natural landscapes of the Salt Lake City region of Utah, one of the most rapidly urbanizing areas in North America. Results were assimilated through five regional landscape typologies—Ecological, Hydrological, Recreational, Working Lands, and Community—and indicated those highest ranked landscape areas which provided multiple ecosystem services. These findings support collaborative decision making among diverse stakeholders with overlapping objectives and illustrates pathways to the development of ecosystem service criteria. This paper contributes to a better understanding of how to integrate data and visualize the strategic approaches required for sustainable planning and management, particularly in urban and urbanizing regions where complex socioecological landscapes predominate.

1346. The Risk of Readmission after RSV Hospitalization Among Children Younger than 5 Years

Background Respiratory Syncytial Virus (RSV) is one of the most common causes of childhood lower respiratory tract infection (LRTI) leading to hospitalization worldwide. Readmissions following viral LRTI hospitalization are common, however rates, timing and causes of readmission following RSV LRTI hospitalization are understudied. We evaluated readmissions occurring during 1-year post-discharge of RSV hospitalization. Methods We prospectively identified children < 5 years of age hospitalized with laboratory-confirmed RSV LRTI at Primary Children’s and Riverton hospitals in Salt Lake City, Utah during the 2019-2020 RSV season. An electronic alert system identified all-cause readmission between November 2019 and April 2021. Discharge diagnoses of readmissions were reviewed by two pediatricians. We calculated the incidence rate of all-cause and respiratory-related readmission. Results A total of 297 children had laboratory-confirmed RSV LRTI hospitalizations during the 2019-2020 RSV season, with 24% admitted to the intensive care unit (ICU) during index RSV hospitalization and 24% having a chronic medical condition. During the 1-year follow-up period, 59 readmissions occurred among 47 patients (Table 1). The incidence rate of all-cause and respiratory-related readmission was 19.9 (95%CI 15.5-24.9) and 13.1 (95%CI 9.5-17.5) per 100 patients, respectively. Median age of readmitted patients was 11 months (interquartile range 5.9-11 months). Median number of readmissions was 1 (range: 1-4), with initial readmissions occurring within 28 days (median) of index admission; most (74%) due to a respiratory-related illness. Second and 3rd admissions were less common and occurred at 67 (median) and 160 (median) days respectively. During all readmissions, 19% of children required ICU admission and 25% had chronic medical conditions. Conclusion All cause and respiratory readmission after Initial hospitalization with RSV LRTI commonly occurred among children < 5 years. These data support the need for RSV vaccines and immunoprophylaxis to prevent RSV hospitalization. A further study with a control group is needed to determine the role of RSV in readmission. Disclosures Yoonyoung Choi, PhD, MS, RPh, Merck (Employee) Lyn Finelli, DrPH, MS, Merck (Employee)

668. Restricting Ordering of Multiplex Gastrointestinal Panel Improves Test Utilization

Background The multiplex gastrointestinal pathogen panel (GIP) is a convenient and quick diagnostic test for determining the infectious etiology of diarrhea. It identifies several of the most common pathogens associated with gastroenteritis. However, it is expensive, and test results may not impact care, given that several of the pathogens in the panel are managed expectantly. We describe our experience with a diagnostic stewardship initiative to resolve the overuse of this testing method. Methods We performed a pre/post study of GIPs ordered for inpatients 18 years old and older from December 19, 2018, to December 18, 2020, at Mayo Clinic hospital in Rochester, Minnesota. GIP orders for inpatients were limited to the first 72 hours of hospitalization starting December 19, 2019. Orders after 72 hours were encouraged to be changed to Clostridioides difficile NAAT testing or sent to an infectious disease provider to override on a case-by-case basis. Our hospitals used BioFire® FilmArray® Gastrointestinal Panel (BioFire Diagnostics, Salt Lake City, Utah). Results A total of 2,641 GIPs were performed during the study period. There were 1,568 GIPs (3.3/100 hospitalizations) in the pre-intervention period compared to 1,073 (2.6/100 hospitalizations) post-intervention, representing a drop of 21.2%. The most common pathogen detected was C. difficile (toxin A/B) (48.8%, n=402), followed by norovirus (17.5%, n=144). The overall test positivity rate was 27.9% (n=736). The test positivity rate decreased 1.8% from 28.6% (n=448) to 26.8% (n=288) after the restriction (p=0.33). The proportion of C. difficile among all pathogens detected increased from 48.5% to 49.7% (p=0.67). Table 1. Pre- and Post-Intervention Test Positivity Rate of Specific Pathogens in GIP Conclusion Our study showed that restricting the ordering of GIP to the first 72 hours of hospitalization and directing providers to standalone C. difficile NAAT testing resulted in a reduction of GIPs performed. There were marginal changes in the test positivity rate of GIP. A limitation of our study is that the timing of post-intervention coincided with the COVID-19 pandemic, which had unpredictable effects on hospital practice and patient admissions. Ideally, future quality improvement projects should increase the test positivity of pathogens other than C. difficile while lowering the GIP use in diagnosing C. difficile colitis. Disclosures John C. O'Horo, Sr., MD, MPH, Bates College and Elsevier Inc (Consultant)

Multicenter evaluation of the FilmArray Meningitis/Encephalitis assay in a routine setting

Introduction. The FilmArray Meningitis/Encephalitis (FA-ME) Panel (Biofire, Salt Lake City, Utah, US) enables fast and automated detection of 14 pathogens in cerebrospinal fluid (CSF). Gap statement. The performance of the FA-ME panel in a real routine setting has not yet been described and could lead to better patient management in cases of good performance. Aim. This multicenter study verified the FA-ME panel analytical performance in a routine hospital setting. Methodology. Between April 2016 and April 2018, 454 CSF samples were analysed with the FA-ME panel and compared with routine diagnostics. In cases of discrepancy or lack of a comparator result, a profound analysis based on patient records and other laboratory results was performed. Results. A first analysis of 65 frozen samples, suspicious for meningitis had a 89 % concordance with routine diagnostics. The limit of detection (LOD) was confirmed for all pathogens except for Streptococcus agalactiae and a strain of Haemophilus influenzae (Escherichia coli K1 and Cryptococcus gattii LOD experiments were not performed). The routine evaluation showed a positive result in 114 (25 %) clinical samples for at least one target. In three samples co-infections were found. After discrepancy analysis, overall sensitivity was 98 % (false negative FA-ME results for one HSV2, two HSV1 and two parechovirus). Four FA-ME results were considered false positive (two HHV6, one VZV and one E. coli K1), resulting in an overall specificity of >99 %. A clinical added value of the assay was seen in the diagnosis of eight cases of bacterial meningitis. Conclusion. Because of its rapidity and ease of use, the FA-ME panel has great potential in the diagnosis of central nervous infections. Implementation can improve clinical management, but costs and analytical limitations need to be addressed to convince clinicians and laboratories of its value.

Real-world comparison of febrile neutropenia rates with same-day versus next-day administration of pegfilgrastim.

299 Background: Febrile neutropenia (FN) is a common side effect of myelosuppressive chemotherapy. Per guidelines, prophylactic pegfilgrastim is to be given 24-72 hours after chemotherapy in each cycle, but administering pegfilgrastim within 24 hours of chemotherapy (same day) is commonly done to reduce the burden on patients (pts) and healthcare systems. The ideal timing is under debate in the supportive oncology care field, but an increasing body of knowledge supports same-day administration as an option. The objective of this study was to compare the incidence of FN after same-day vs next-day administration of pegfilgrastim in pts with cancer receiving cytotoxic chemotherapy. Methods: A real-world, retrospective study of electronic health records of pts treated at Utah Cancer Specialists (Salt Lake City, UT) between February 2018 and December 2020 was conducted. Pts included in the study had a diagnosis of breast cancer, diffuse large B-cell lymphoma, or other cancers (eg. other lymphomas, prostate cancer); received a myelosuppressive chemotherapy regimen; and were administered either same-day or next-day prophylactic pegfilgrastim. FN was physician diagnosed; differences in FN incidence with same-day vs next-day pegfilgrastim were evaluated using a Chi-square test and Wald confidence limits. Results: 297 pts were included in this analysis. Most pts (63.6%) had a diagnosis of breast cancer, 23.6% had lymphoma, and 12.8% had other cancers. Pts received a broad range of chemotherapy regimens, with dose-dense doxorubicin and cyclophosphamide being the most common (43.4%). In cycle 1, pegfilgrastim administration timing was balanced between same-day (39.7% [118/297]) and next-day (60.3% [179/297]). The pegfilgrastim administration day changed in subsequent cycles in 27 pts (9.1%): 4 pts in the cycle 1 same-day group and 23 pts in the cycle 1 next-day group. In cycle 1, 7/117 pts (6.0%) in the same-day pegfilgrastim group and 12/180 (6.7%) pts in the next-day group experienced ≥1 episode of FN. Across all cycles, 11/118 pts (9.3%) in the same-day pegfilgrastim group and 16/179 (8.9%) pts in the next-day group experienced ≥1 episode of FN. The difference in incidence of FN between same-day vs next-day pegfilgrastim was not statistically significant in cycle 1 (0.68% [95% CI –5.0% to 6.3%]; P=.814) and across all cycles (–0.38% [95% CI –7.1% to 6.3%]; P=.910). Conclusions: The overall incidence of FN was low in this pt population receiving prophylactic pegfilgrastim, and no significant differences were detected between same-day and next-day pegfilgrastim administration. These data support the same-day administration of prophylactic pegfilgrastim.