Publications by authors named "Birkholz M"

Administrative databases are powerful tools for pediatric research but lack patient-level microbiology results. This study aimed to determine the accuracy of pathogen discharge diagnosis codes for children hospitalized with acute hematogenous musculoskeletal infections (MSKIs). Medical records for 244 children hospitalized with acute hematogenous MSKIs were manually reviewed to determine which bacterial pathogen, if any, was identified for each MSKI based on microbiology results obtained during the hospitalization.

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In this study, the influence of using rectangular waveforms is comprehensively investigated on the separation and sorting efficiency of dielectrophoretic (DEP) processes. Besides positive effects on DEP experiments, cases of a diminished force due to rectangular waveforms are investigated and discussed. This investigation encompasses two primary experimental setups.

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Background: While Streptococcus pneumoniae (Spn) is the leading cause of pediatric complicated community-acquired pneumonia (cCAP), it is infrequently recovered by culture-based methods. We studied the real-world clinical impact of an Spn polymerase chain reaction (PCR) assay for pleural fluid.

Methods: This pre-post quasi-experimental cohort study compared pathogen detection, antibiotic usage, and outcomes in children hospitalized with cCAP requiring pleural effusion or empyema drainage at Children's Hospital Colorado between 2016 and 2023.

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Surveillance for emerging pathogens is critical for developing early warning systems to guide preparedness efforts for future outbreaks of associated disease. To better define the epidemiology and burden of associated respiratory disease and acute flaccid myelitis (AFM), as well as to provide actionable data for public health interventions, we developed a multimodal surveillance program in Colorado, USA, for enterovirus D68 (EV-D68). Timely local, state, and national public health outreach was possible because prospective syndromic surveillance for AFM and asthma-like respiratory illness, prospective clinical laboratory surveillance for EV-D68 among children hospitalized with respiratory illness, and retrospective wastewater surveillance led to early detection of the 2022 outbreak of EV-D68 among Colorado children.

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Background And Objectives: The introduction of multiplex gastrointestinal panels at our institution resulted in increased Clostridioides difficile (C. difficile) detection and stool test utilization. We aimed to reduce hospital-onset C.

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Over the last decade, there have been widespread efforts to reduce non-evidence-based therapies for viral bronchiolitis. We question whether this change in practice has inadvertently impacted the diagnosis and management of other pediatric lower-respiratory-tract illnesses. We used the Pediatric Health Information System (PHIS) and logistic regression to describe trends in relative diagnosis frequency of bronchiolitis, viral pneumonia, and reactive airway disease (RAD)/asthma as well as systemic corticosteroid use among children of the age range 1 to 4 years over a 10-year period.

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Article Synopsis
  • The study investigates which hospitalized children with acute gastroenteritis (AGE) benefit from gastrointestinal panel (GIP) testing, aiming to reduce unnecessary tests that can lead to higher costs and overdiagnosis.
  • It analyzes data from pediatric patients who underwent GIP testing between 2015 and 2018, focusing on factors like age, order indications, and demographics to determine their association with actionable test results.
  • Findings suggest that older age, bloody diarrhea, and international travel are linked to actionable results in healthy children, while these associations do not apply to those with complex chronic conditions, indicating a need for better testing guidelines.*
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Background: In the fall of 2022, we observed a sharp rise in pediatric Invasive Group A Streptococcus (iGAS) hospitalizations in Colorado. We compared the epidemiology, clinical features, and patient outcomes in this outbreak to prior years.

Methods: Between October 2022 and April 2023, we prospectively identified and reviewed iGAS cases in hospitalized pediatric patients at Children's Hospital Colorado.

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Nucleoside analogues are important compounds for the treatment of viral infections or cancers. While (chemo-)enzymatic synthesis is a valuable alternative to traditional chemical methods, the feasibility of such processes is lowered by the high production cost of the biocatalyst. As continuous enzyme membrane reactors (EMR) allow the use of biocatalysts until their full inactivation, they offer a valuable alternative to batch enzymatic reactions with freely dissolved enzymes.

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Background And Objectives: Acute hematogenous musculoskeletal infections (MSKI) are medical emergencies with the potential for life-altering complications in afflicted children. Leveraging administrative data to study pediatric MSKI is difficult as many infections are chronic, nonhematogenous, or occur in children with significant comorbidities. The objective of this study was to validate a case-finding algorithm to accurately identify children hospitalized with acute hematogenous MSKI using administrative billing codes.

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The performance of receptor-based biosensors is often limited by either diffusion of the analyte causing unreasonable long assay times or a lack of specificity limiting the sensitivity due to the noise of nonspecific binding. Alternating current (AC) electrokinetics and its effect on biosensing is an increasing field of research dedicated to address this issue and can improve mass transfer of the analyte by electrothermal effects, electroosmosis, or dielectrophoresis (DEP). Accordingly, several works have shown improved sensitivity and lowered assay times by order of magnitude thanks to the improved mass transfer with these techniques.

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Microfluidic dielectrophoretic (DEP) devices enable the label-free separation and isolation of cells based on differences in their electrophysiological properties. The technique can serve as a tool in clinical diagnostics and medical research as it facilitates the analysis of patient-specific blood composition and the detection and isolation of pathogenic cells like circulating tumor cells or malaria-infected erythrocytes. This review compares different microfluidic DEP devices to separate platelets, erythrocytes and leukocytes including their cellular subclasses.

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Microalgae constitute an abundant source of poly-unsaturated fatty acids which are applied in various biotechnological fields such as pharmaceuticals and food supplement. Separating microalgae cells with respect to their lipid content would establish a relevant analytical technique. The present study demonstrates an electrical approach for the separation of the lipid-producing microalgae using the effect of dielectrophoresis (DEP) in a microfluidic flow cell.

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Importance: Endotracheal aspirate cultures are commonly collected from patients with mechanical ventilation to evaluate for ventilator-associated pneumonia or tracheitis. However, the respiratory tract is not sterile, making differentiating between colonization from bacterial infection challenging, and results may be unreliable owing to variable specimen quality and sample processing across laboratories. Despite these limitations, clinicians routinely interpret bacterial growth in endotracheal aspirate cultures as evidence of infection, sometimes regardless of organism significance, prompting antibiotic treatment.

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Objectives: Many hospitals have transitioned from conventional stool diagnostics to rapid multiplex polymerase chain reaction gastrointestinal panels (GIP). The clinical impact of this testing has not been evaluated in children. In this study, we compare use, results, and patient outcomes between conventional diagnostics and GIP testing.

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The combination of extreme miniaturization with a high sensitivity and the potential to be integrated in an array form on a chip has made silicon-based photonic microring resonators a very attractive research topic. As biosensors are approaching the nanoscale, analyte mass transfer and bonding kinetics have been ascribed as crucial factors that limit their performance. One solution may be a system that applies dielectrophoretic forces, in addition to microfluidics, to overcome the diffusion limits of conventional biosensors.

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Following implementation of the FilmArray meningitis and encephalitis panel, which enables rapid syndromic cerebrospinal fluid testing, HSV testing doubled in children >60 days with suspected central nervous system infection at Children's Hospital Colorado. Acyclovir initiation was unchanged, but duration decreased. Diagnostic and antimicrobial stewardship is needed for MEP optimization.

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Microalgae biotechnology has a high potential for sustainable bioproduction of diverse high-value biomolecules. Some of the main bottlenecks in cell-based bioproduction, and more specifically in microalgae-based bioproduction, are due to insufficient methods for rapid and efficient cell characterization, which contributes to having only a few industrially established microalgal species in commercial use. Dielectrophoresis-based microfluidic devices have been long established as promising tools for label-free handling, characterization, and separation of broad ranges of cells.

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Objectives: To evaluate whether the implementation of a multiplex gastrointestinal pathogen panel (GIP) was associated with changes in Clostridioides difficile (C difficile) testing and detection rates.

Study Design: We conducted an observational study using interrupted time series analysis and included pediatric patients with testing capable of detecting C difficile. From 2013 to 2015 ("conventional diagnostic era"), stool testing included C difficile-selective polymerase chain reaction and other pathogen-specific tests.

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Objective: Acute kidney injury (AKI) is a common occurrence among hospitalized children and leads to increased mortality and prolonged length of stay (LOS) in critically ill patients. Few studies have examined the impact of AKI on LOS for common pediatric conditions. We hypothesized that a diagnosis of AKI would be associated with a longer hospital LOS and increased exposure to nephrotoxic medications for all patients.

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Inertial microfluidic systems have been arousing interest in medical applications due to their simple and cost-efficient use. However, comparably small sample volumes in the microliter and milliliter ranges have so far prevented efficient applications in continuous bioprocesses. Nevertheless, recent studies suggest that these systems are well suited for cell separation in bioprocesses because of their facile adaptability to various reactor sizes and cell types.

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Background: Children's Hospital Colorado created a unique method of antimicrobial stewardship, called handshake stewardship, that effectively decreased hospital anti-infective use and costs in its pilot year (2013). Handshake stewardship is distinguished by: (1) the lack of prior authorization; (2) a review of all prescribed anti-infectives; (3) a shared review by the physician and the pharmacist; and (4) a daily, rounding-based, in-person approach to supporting providers. We sought to reevaluate the outcomes of the program after 5 years of experience, totaling 8 years of data.

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Objective: To evaluate variations in treatment practice and compliance with national guidelines for the diagnostic evaluation of children with Kawasaki disease (KD).

Study Design: We used the Pediatric Hospital Information System database to analyze demographic, laboratory and treatment data from patients admitted with KD between January 1, 2006, and December 31, 2015.

Results: During the study period, 12,089 children with KD were diagnosed.

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The application of Raman spectroscopy as a monitoring technique for bioprocesses is severely limited by a large background signal originating from fluorescing compounds in the culture media. Here, we compare time-gated Raman (TG-Raman)-, continuous wave NIR-process Raman (NIR-Raman), and continuous wave micro-Raman (micro-Raman) approaches in combination with surface enhanced Raman spectroscopy (SERS) for their potential to overcome this limit. For that purpose, we monitored metabolite concentrations of Escherichia coli bioreactor cultivations in cell-free supernatant samples.

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