Digital Commons Network^™

The Role Of Calprotectin In T-Lymphocyte Driven Inflammation In A Mouse Model Of Psychological Trauma, Cassandra Moshfegh

Theses & Dissertations

Post-traumatic stress disorder (PTSD) is a debilitating psychological disorder that affects nearly 45 million Americans. This mental disorder is characterized by behavioral symptoms such as learned helplessness, hyperarousal, withdrawal, and flashbacks. The deleterious effects of PTSD are far-reaching and go beyond behavioral dysfunction, as these individuals are at a three-fold higher risk of comorbid inflammatory diseases. Autonomic, metabolic, and cardiovascular diseases plague these individuals later in their lifetime, however, the mechanistic link connecting psychological trauma to this systemic peripheral immunological dysfunction remains elusive. T-lymphocyte-induced inflammation plays a significant role in all these disease pathologies. Previous work from our laboratory demonstrated …

Innate Immunity In The Pathobiology And Treatment Of Infectious And Neurodegenerative Diseases, Mai Mostafa

Theses & Dissertations

Mononuclear phagocytes (MPs; monocytes, macrophages, and dendritic cells) are the governors of innate immunity which is the body’s first line of defense against microbial pathogens. They act beneficial or detrimental. They are crucial for an effective non-specific immune response to invading pathogens by engulfing, destroying, then eliciting an adaptive specific immune response. Given their pivotal functions in the host immune defense, studying MP immune responses in disease is paramount important for understanding disease pathobiology and uncovering therapeutic strategies.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the driver of acute respiratory distress syndrome (ARDS) in coronavirus disease 2019 (COVID-19) amongst …

Gut Commensals Modulate Siv/Shiv Pathogenesis And Therapeutics, Samuel Johnson

Theses & Dissertations

Despite significant advancements in combination antiretroviral therapy (cART), ongoing inflammation in the brain and gut remain two of the most significant hurdles in the health of people living with human immunodeficiency virus (HIV). Additionally, a viral reservoir in each compartment inhibits cure efforts by allowing rapid viral rebound following cART interruption. Emerging understanding of the gut-brain axis (GBA) implicates each compartment in the modulation of the other in a complex bi-directional interaction mediated by vagus innervation, circulating lymphocytes, and microbiome composition and biproducts. Using multiple models of the simian (and simian-human) immunodeficiency virus (SIV/SHIV) and therapeutic intervention, I present how …

Frailty And Neurocognition In Prostate Cancer, Lindsey Hanson

Theses & Dissertations

Prostate cancer (PCa) treatment often leads to distressing side effects ranging from muscle loss, physical inactivity, and fatigue to cancer associated cognitive decline (CACD). Evidence suggests that men treated with androgen deprivation therapy (ADT) may have a specifically high risk of CACD, partially due to increased frailty. However, the current literature on cognitive effects of ADT is equivocal. Therefore, the primary objectives of this study were to (1) compare cognitive function, physical activity (PA), and fitness in men receiving ADT, men scheduled to receive radiation, and men under active surveillance for PCa; (2) examine changes in cognitive performance and PA …

Paf1/Pd2 Augments Pancreatic Cancer Progression And Mediates Radiation And Chemoresistance, Sanchita Rauth

Theses & Dissertations

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Reflective Journaling Intervention To Impact Self-Awareness, Professional Health, And Overall Well-Being In Nurses, Brittany M. Langan, Katherine Keppen

Doctor of Nursing Practice Projects: College of Nursing

Background. Burnout among nurses has been on the rise and was exacerbated with the pandemic. Reflective journaling after work may be a strategy to decrease feelings of burnout. Reflective journaling, as an intervention, has been shown to improve self-awareness, compassion fatigue, and burnout among nurses. The purpose of this study was to pilot a 4-week reflective journaling intervention in hospital-based nurses and describe participant professional quality of life, self-awareness, and overall well-being.

Theoretical Framework. The Theory of Reasoned Action (TRA) was chosen as the theoretical framework because it identifies the belief that performing a particular behavior will lead to a …

The Impact Of Simulation-Based Mastery Learning For Central Venous Catheter Dressing Changes With Staff Nurses At A Nebraska Critical Access Hospital, Paige Pavlik, Michaela Haddock

Doctor of Nursing Practice Projects: College of Nursing

Abstract

Purpose

The purpose of this pilot feasibility study was to assess if a simulation-based mastery learning (SBML) intervention on central venous catheter (CVC) dressing changes by staff nurses at Nemaha County Hospital could further develop staff nurses’ central line care skills by increasing their knowledge of a central line dressing change, improving their comfort level and learning self-efficacy with central line care, determining if there is a relationship between knowledge, learning self-efficacy and comfort in the clinical area, and assessing nurses’ satisfaction on the SBML intervention. The clinical research questions being explored are, “Will nurses in a Nebraska critical …

Impact Of The Filmarray® Meningitis/Encephalitis Panel On Clinical Practice In Pediatrics; A Multicentered Study, John Chatterton, Aleisha Nabower, Nathan Gollehon, Nathaniel Goodrich, Prabi Rajbhandari, Jaclyn Eisenberg, Kimberly Martin, Megan Woslager, Maheswari Ekambaran, Krow Ampofo, Elizabeth Lyden, Jessica Snowden

Child Health Research Institute Pediatric Research Forum

Background

The FilmArray® Meningitis/Encephalitis Panel (MEP) is a rapid multiplex assay that tests cerebrospinal fluid (CSF) for 14 common central nervous system (CNS) pathogens, with results available in hours as opposed to days with the gold standard CSF culture. Current literature on the impact of MEP testing on length of stay (LOS) and antimicrobial use in pediatric patients is from only single site studies with variable results.

Hypothesis

MEP testing in pediatric patients would be associated with a decreased LOS, time on IV antibiotics, and time to narrowing antibiotics.

Design/Methods

We conducted a retrospective study of 5 sites. Inclusion criteria …

Case Report Of Rare Mycobacterium Isolated From Mediastinal Abscess, Olivia Person, Andrew S. Huang Pacheco, Hana Niebur, Melissa Suh, Kari Neemann

Child Health Research Institute Pediatric Research Forum

Introduction

Mycobacterium arupense, a member of the Mycobacterium terrae complex identified in 2016, rarely causes infections despite isolation from multiple environmental sources, including water, soil and fish tanks.¹ Case reports have described tenosynovitis, osteomyelitis and disseminated infection in an immunocompromised host.^1-3 Here we describe a case of M. arupense identified in a polymicrobial mediastinal abscess in a pediatric patient subsequently diagnosed with autosomal dominant hyper-IgE syndrome (AD-HIES).

Case Description

A 4-year-old female with a history of pneumonia, herpetic skin infection, orbital cellulitis, and eczema presented in respiratory distress with concern for pneumonia. Imaging revealed a posterior mediastinal …

Respiratory Syncytial Virus (Rsv) Laboratory Surveillance And Mortality In Nebraska, 2016 – 2021, Derek Bumgardner

Capstone Experience: Master of Public Health

Respiratory syncytial virus (RSV) is a common respiratory virus affecting children and adults. The United States RSV peak season occurs regularly between October to May, but in April 2021, an unexpected United States interseason RSV epidemic ensued. RSV laboratory testing has changed in the United States due to increased use of nucleic acid amplification testing (NAAT) rather than antigen-based testing, affecting how RSV seasonal epidemics are determined. Nebraska linked RSV laboratory and death certificate data (2016-2021) were used to calculate crude, specific and adjusted RSV case and mortality rates by age, sex, race, and ethnicity. A Cochran – Armitage test …

Assessing Meat Processing Workers’ Attitudes And Concerns Regarding Covid-19 Vaccination, Karen Schmeits

Capstone Experience: Master of Public Health

The COVID-19 pandemic has impacted industries across the globe. Specifically, for meat processing (meatpacking) facilities, the pandemic has changed the way facilities operate, how the workers perform tasks, and how workers perceive their health. The development of an FDA approved COVID-19 vaccine brought hope to meat processing employers and workers. However, little research has been conducted to know how meat processing workers feel about vaccines generally and how they perceive the COVID-19 vaccine. The purpose of this cross-sectional study was to investigate preventive vaccine determinants and attitudes and concerns specifically regarding the COVID-19 vaccine. Surveys were conducted with 128 meat …

Effect Of Climate Variability On Lyme Disease Cases In The United States – A Retrospective Study, Larissa Mark

Capstone Experience: Master of Public Health

Vector-borne illnesses are a growing serious global public health threat. According to the CDC, Lyme disease (LD) is the most common vector-borne disease in the United States. It is caused by the bacterium Borrelia burgdorferi and is transmitted to humans through the bite of an infected black-legged tick. Since the discovery, LD has increased in both incidence and geographical distribution. Vector life cycles and disease transmission are highly sensitive to abiotic conditions; as such, it is expected that climate change will alter the geographic distribution and magnitude of vector-borne illnesses. Certain facets of climate change like precipitation patterns, greater climate …

Misinformation And Vaccine Hesitancy Determinants: The Significance Of Framed Public Health Messaging, Alexandra I. Todd

Capstone Experience: Master of Public Health

In 2020, the SARS-CoV-2 (COVID19) outbreak effectively disrupted worldwide operation for months, leading to tremendous economic loss and adverse health outcomes. While countries grappled to control the virus and scientists worked around the clock to deliver a vaccine in record time, a pubic health communication crisis emerged. The spread of false and misleading information, also known as misinformation, has proved to be a barrier in the fight against COVID19 and its vaccination effort. Many factors including the rise of social media, distrust of government, polarization of news sources, and fragmented media have created an environment susceptible to misinformation. Utilized correctly, …

Local Public Health Legal Landscape Report, Christina Hitz

Capstone Experience: Master of Public Health

This report provides a framework for understanding and examining local public health authority and implications of proposed legislative changes, specifically whether a shift is occurring in public health authority from the executive to the legislative branch. It compares the public health governance and legal infrastructure of states making a shift in 2021 relative to Nebraska’s current and proposed public health infrastructure and provides a synopsis of the legal context for and the scope of local public health authority currently in Nebraska. Three resources were used to create two tables to compare both states with legislative changes in 2021 indicating a …

The Epidemiology Of Extended Spectrum Beta-Lactamase-Producing Enterobacterales In Nebraska, 2018 – 2021, Axel A. Vazquez Deida

Capstone Experience: Master of Public Health

Background: Extended spectrum beta-lactamase (ESBL)-producing Enterobacterales are considered a serious public health threat by the United States Centers for Disease Control and Prevention. However, surveillance of ESBL-producing Enterobacterales is currently limited to select states and the epidemiology of these antibiotic-resistant bacteria in Nebraska is still not well understood.

Objective: To describe the incidence of ESBL-producing Enterobacterales across local health department (LHD)-jurisdictions as well as at the state-level over time and assess population-specific factors associated with infection or colonization with these pathogens in Nebraska.

Methods: A retrospective, cross-sectional analysis of public health surveillance data reported to the Nebraska Department of …

A Systematic Literature Review Of The Use Of Technology As An Emergency Preparedness Tool To Control And Contain The Covid-19 Pandemic, Alyssa Spartz

Capstone Experience: Master of Public Health

Various tools and strategies have been utilized in response to the COVID-19 pandemic. In addition to preexisting measures, novel mechanisms and methods have also been developed since the COVID-19 pandemic began to address several different needs worldwide. Technology, for example, has served as a unique and multifunctional tool to aid with controlling and containing the pandemic. While studies and reviews have been conducted to analyze specific types of technology, such as digital applications, a gap in the literature currently exists that fails to comprehensively understand and compare how multiple types of technology were implemented to address the COVID-19 pandemic. This …

Housing To Health: A Literature Review Analyzing Housing Pathways And Policy Initiatives, Evan P. Lesser

Capstone Experience: Master of Public Health

Housing is a vital aspect of an individual’s ability to enjoy a healthy lifestyle. It is so integral that the United Nations has stated that housing is a human right and extends beyond just basic shelter where housing should provide a certain level of structural integrity of the infrastructure, security, affordability, and access to surrounding resources. Existing research studying the relationship between housing and health outcomes suggest those with poor housing exhibit higher levels of chronic conditions such as asthma, heart disease, and diabetes, and higher chances of accidents within the home. The goal of this literature review, which has …

The Effect Of Post-Traumatic Stress Disorder On First Responders Following A Disaster: A Literature Review, Briar Butner

Capstone Experience: Master of Public Health

First responders work in a high-stress environment that can potentially produce traumatic situations. This includes aiding in the recovery and response efforts of critical events such as a disaster. A significant risk factor for developing post-traumatic stress disorder symptoms is people who have been through a disaster (National Institute of Mental Health, 2019). This literature review aims to search for evidence on PTSD in first responders following a disaster, identify the factors associated with the development of PTSD, and make recommendations on best practices to reduce or mitigate the incidences of PTSD. The search was conducted in three academic databases: …

Impact Of The Covid-19 Pandemic On The Malaria Control Program At The Epidemic Treatment Center Of Regional Hospital Of Kindia, Guinea, Mohamed Keita

Capstone Experience: Master of Public Health

The impact of infectious disease outbreaks and pandemics on the health systems could be alarming especially when there is an overlap in clinical manifestations of two infectious conditions. Despite the remarkable progress in reducing the burden of malaria in Africa since 2000, the COVID-19 pandemic has impacted the malaria control program. This paper describes the impact of the COVID- 19 pandemic on the health service delivery in Guinea and its consequences on malaria control programs before and during the COVID 19 pandemic. This paper aims to assess the impact of the COVID 19 pandemic on the malaria control program between …

Comparative Transmissibility Of Sars-Cov-2 Variants Delta And Alpha In New England, Usa, Rebecca Earnest, Rockib Uddin, Nicholas Matluk, Nicholas Renzette, Katherine J. Siddle, Christine Loreth, Gordon Adams, Christopher H. Tomkins-Tinch, Mary E. Petrone, Jessica E. Rothman, Mallery I. Breban, Robert Tobias Koch, Kendall Billig, Joseph R. Fauver, Chantal B.F. Vogels, Sarah Turbett, Kaya Bilguvar, Bony De Kumar, Marie L. Landry, David R. Peaper, Kevin Kelly, Greg Omerza, Heather Grieser, Sim Meak, John Martha, Hannah H. Dewey, Susan Kales, Daniel Berenzy, Kristin Carpenter-Azevedo, Ewa King, Richard C. Huard, Sandra C. Smole, Catherine M. Brown, Timelia Fink, Andrew S. Lang, Glen R. Gallagher, Pardis C. Sabeti, Stacey Gabriel, Bronwyn L. Macinnis, New England Variant Investigation Team, Ryan Tewhey, Mark D. Adams, Daniel J. Park, Jacob E. Lemieux, Nathan D. Grubaugh

Journal Articles: Epidemiology

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant quickly rose to dominance in mid-2021, displacing other variants, including Alpha. Studies using data from the United Kingdom and India estimated that Delta was 40-80% more transmissible than Alpha, allowing Delta to become the globally dominant variant. However, it was unclear if the ostensible difference in relative transmissibility was due mostly to innate properties of Delta's infectiousness or differences in the study populations. To investigate, we formed a partnership with SARS-CoV-2 genomic surveillance programs from all six New England US states. By comparing logistic growth rates, we found that Delta …

T-Lymphocyte Tyrosine Hydroxylase Regulates T H 17 T-Lymphocytes During Repeated Social Defeat Stress, Safwan K. Elkhatib, Cassandra M. Moshfegh, Gabrielle F. Watson, Adam J. Case

Journal Articles: Cellular & Integrative Physiology

Posttraumatic stress disorder (PTSD) is a debilitating psychiatric disorder which results in deleterious changes to psychological and physical health. Patients with PTSD are especially susceptible to life-threatening co-morbid inflammation-driven pathologies, such as autoimmunity, while also demonstrating increased T-helper 17 (T_H17) lymphocyte-driven inflammation. While the exact mechanism of this increased inflammation is unknown, overactivity of the sympathetic nervous system is a hallmark of PTSD. Neurotransmitters of the sympathetic nervous system (i.e., catecholamines) can alter T-lymphocyte function, which we have previously demonstrated to be partially mitochondrial redox-mediated. Furthermore, we have previously elucidated that T-lymphocytes generate their own catecholamines, and strong …

Zip8-Mediated Intestinal Dysbiosis Impairs Pulmonary Host Defense Against Bacterial Pneumonia, Derrick R. Samuelson, Deandra R. Smith, Kelly C. Cunningham, Todd A. Wyatt, Sannette C. Hall, Daryl J. Murry, Yashpal S. Chhonker, Daren L. Knoell

Journal Articles: Environmental, Agricultural & Occupational Health

Pneumococcal pneumonia is a leading cause of morbidity and mortality worldwide. An increased susceptibility is due, in part, to compromised immune function. Zinc is required for proper immune function, and an insufficient dietary intake increases the risk of pneumonia. Our group was the first to reveal that the Zn transporter, ZIP8, is required for host defense. Furthermore, the gut microbiota that is essential for lung immunity is adversely impacted by a commonly occurring defective ZIP8 allele in humans. Taken together, we hypothesized that loss of the ZIP8 function would lead to intestinal dysbiosis and impaired host defense against pneumonia. To …

Surface Modification Of Biodegradable Microparticles With The Novel Host-Derived Immunostimulant Cpdi-02 Significantly Increases Short-Term And Long-Term Mucosal And Systemic Antibodies Against Encapsulated Protein Antigen In Young Naïve Mice After Respiratory Immunization, Jacob E. Parriott, Jason P. Stewart, D. David Smith, Stephen M. Curran, Christopher D. Bauer, Todd A. Wyatt, Joy A. Phillips, Elizabeth Lyden, Geoffrey M. Thiele, Joseph A. Vetro Phd

Journal Articles: Environmental, Agricultural & Occupational Health

Generating long-lived mucosal and systemic antibodies through respiratory immunization with protective antigens encapsulated in nanoscale biodegradable particles could potentially decrease or eliminate the incidence of many infectious diseases, but requires the incorporation of a suitable mucosal immunostimulant. We previously found that respiratory immunization with a model protein antigen (LPS-free OVA) encapsulated in PLGA 50:50 nanoparticles (~380 nm diameter) surface-modified with complement peptide-derived immunostimulant 02 (CPDI-02; formerly EP67) through 2 kDa PEG linkers increases mucosal and systemic OVA-specific memory T-cells with long-lived surface phenotypes in young, naïve female C57BL/6 mice. Here, we determined if respiratory immunization with LPS-free OVA encapsulated in …

Type I Ifn Signaling Protects Mice From Lethal Sars-Cov-2 Neuroinvasion., Md Bashir Uddin, Yuejin Liang, Shengjun Shao, Sunil Palani, Michael Mckelvey, Scott C. Weaver, Keer Sun

Journal Articles: Pathology and Microbiology

Multiple organ damage is common in patients with severe COVID-19, even though the underlying pathogenic mechanisms remain unclear. Acute viral infection typically activates type I IFN (IFN-I) signaling. The antiviral role of IFN-I is well characterized in vitro. However, our understanding of how IFN-I regulates host immune response to SARS-CoV-2 infection in vivo is incomplete. Using a human ACE2-transgenic mouse model, we show in the present study that IFN-I receptor signaling is essential for protection against the acute lethality of SARS-CoV-2 in mice. Interestingly, although IFN-I signaling limits viral replication in the lung, the primary infection site, it is dispensable …

Access, Socioeconomic Environment, And Death From Covid-19 In Nebraska, He Bai, Michelle M. Schwedhelm, John-Martin Lowe, Rachel Lookadoo, Daniel R. Anderson, Abigail Lowe, James V. Lawler, M. Jana Broadhurst, David Brett-Major

Journal Articles: Epidemiology

Our study assesses whether factors related to healthcare access in the first year of the pandemic affect mortality and length of stay (LOS). Our cohort study examined hospitalized patients at Nebraska Medicine between April and October 2020 who were tested for SARS-CoV-2 and had a charted sepsis related diagnostic code. Multivariate logistic was used to analyze the odds of mortality and linear regression was used to calculate the parameter estimates of LOS associated with COVID-19 status, age, gender, race/ethnicity, median household income, admission month, and residential distance from definitive care. Among 475 admissions, the odds of mortality is greater among …

Catabolic Ornithine Carbamoyltransferase Activity Facilitates Growth Of Staphylococcus Aureus In Defined Medium Lacking Glucose And Arginine, Itidal Reslane, Cortney R. Halsey, Amanda Stastny, Barbara J. Cabrera, Jong-Sam Ahn, Dhananjay Shinde, Madeline R. Galac, Margaret F. Sladek, Fareha Razvi, Mckenzie K. Lehman, Kenneth W. Bayles, Vinai Chittezham Thomas, Luke D. Handke, Paul D. Fey

Journal Articles: Pathology and Microbiology

Previous studies have found that arginine biosynthesis in Staphylococcus aureus is repressed via carbon catabolite repression (CcpA), and proline is used as a precursor. Unexpectedly, however, robust growth of S. aureus is not observed in complete defined medium lacking both glucose and arginine (CDM-R). Mutants able to grow on agar-containing defined medium lacking arginine (CDM-R) were selected and found to contain mutations within ahrC, encoding the canonical arginine biosynthesis pathway repressor (AhrC), or single nucleotide polymorphisms (SNPs) upstream of the native arginine deiminase (ADI) operon arcA1B1D1C1. Reverse transcription-PCR (RT-PCR) studies found that mutations within ccpA or ahrC or …

Improved Database Filtering Technology Enables More Efficient Ab Initio Design Of Potent Peptides Against Ebola Viruses, Thomas Ripperda, Yangsheng Yu, Atul Verma, Elizabeth Klug, Michellie Thurman, St. Patrick Reid, Guangshun Wang

Journal Articles: Pathology and Microbiology

The rapid mutations of viruses such as SARS-CoV-2 require vaccine updates and the development of novel antiviral drugs. This article presents an improved database filtering technology for a more effective design of novel antiviral agents. Different from the previous approach, where the most probable parameters were obtained stepwise from the antimicrobial peptide database, we found it possible to accelerate the design process by deriving multiple parameters in a single step during the peptide amino acid analysis. The resulting peptide DFTavP1 displays the ability to inhibit Ebola virus. A deviation from the most probable peptide parameters reduces antiviral activity. The designed …

Performance Of The Universal Vital Assessment (Uva) Mortality Risk Score In Hospitalized Adults With Infection In Rwanda: A Retrospective External Validation Study, Riley Hazard, Danstan Bagenda, Andrew J. Patterson, Julie T. Hoffman, Steven J. Lisco, Olivier Urayeneza, Polyphile Ntihinyurwa, Christopher C. Moore

Journal Articles: Anesthesiology

BACKGROUND: We previously derived a Universal Vital Assessment (UVA) score to better risk-stratify hospitalized patients in sub-Saharan Africa, including those with infection. Here, we aimed to externally validate the performance of the UVA score using previously collected data from patients hospitalized with acute infection in Rwanda.

METHODS: We performed a secondary analysis of data collected from adults ≥18 years with acute infection admitted to Gitwe District Hospital in Rwanda from 2016 until 2017. We calculated the UVA score from the time of admission and at 72 hours after admission. We also calculated quick sepsis-related organ failure assessment (qSOFA) and modified …

Fielding Vaccines-Challenges And Opportunities In Outbreaks, Complex Emergencies, And Mass Gatherings, Laura J. Fischer, Robert C. Rains, Sherry M. Brett-Major, Mikiko Senga, Debra Holden, David Brett-Major

Journal Articles: Epidemiology

With the recent COVID-19 pandemic, the importance of vaccine development, distribution, and uptake has come to the forefront of the public eye. Effectively fielding vaccines during an emergency-whether that emergency is a result of an infectious disease or not-requires an understanding of usual vaccine-related processes; the impact of outbreak, complex emergencies, mass gatherings, and other events on patients, communities, and health systems; and ways in which diverse resources can be applied to successfully achieve needed vaccine uptake. In this review, both the emergency setting and briefly vaccine product design are discussed in these contexts in order to provide a concise …

Uncertainty, Scarcity And Transparency: Public Health Ethics And Risk Communication In A Pandemic, Abigail Lowe, Teck Chuan Voo, Lisa M. Lee, Kelly K. Dineen Gillespie, Christy Feig, Alva O. Ferdinand, Seema Mohapatra, David Brett-Major, Matthew K. Wynia

Journal Articles: Epidemiology

Communicating public health guidance is key to mitigating risk during disasters and outbreaks, and ethical guidance on communication emphasizes being fully transparent. Yet, communication during the pandemic has sometimes been fraught, due in part to practical and conceptual challenges around being transparent. A particular challenge has arisen when there was both evolving scientific knowledge on COVID-19 and reticence to acknowledge that resource scarcity concerns were influencing public health recommendations. This essay uses the example of communicating public health guidance on masking in the United States to illustrate ethical challenges of developing and conveying public health guidance under twin conditions of …