Medical Unit Research Articles

Zinc levels in severe eating disorders.

Severe eating and feeding disorders including Anorexia Nervosa of both restricting (AN-R) and binge-purge (AN-BP) subtypes and Avoidant Restrictive Food Intake Disorder (ARFID) lead to multiple macronutrient and micronutrient deficiencies, including zinc, in the setting of inadequate dietary intake. We investigated whether zinc levels correlated with severe malnutrition, with particular subtypes of eating disorders (EDs), and the effect of the refeeding process. This prospective study included 92 adult patients with severe AN or ARFID hospitalized in a medical stabilization unit. Denver Health staff were recruited as controls. Blood samples were drawn within four days of admission and 72 h of discharge. All inferential analyses were performed using general linear models. Admission zinc levels were statistically significantly lower in cases compared to controls. Admission zinc levels were significantly higher for patients with AN-R than patients with AN-BP. Zinc levels decreased significantly during treatment in cases, compared to controls. ED diagnoses and percent ideal body weight (%IBW) did not appear to predict changes in zinc levels during admission. Given zinc's pervasive roles in metabolism throughout the body as well as common symptoms of deficiency including impaired taste and smell, decreased appetite, and depression, zinc levels could be relevant to the high relapse rate in severe ED. The observed decrease in zinc, which was larger in cases than controls, during refeeding suggests the possibility of a "refeeding hypozincemia" which may present a new therapeutic target. These characteristics make zinc an intriguing focus of future study that could impact the recidivism rate in severe ED. Evidence obtained from well-designed cohort or case-control analytic studies.

Holistic Tri-Service Military Pathology: A Proposed Paradigm for Consolidation.

Historically, military anatomic pathology (AP) services have been significantly compartmentalized, with each branch independently executing its laboratory support mission. The result is redundant and costly duplication of nearly identical services in close geographic proximity. The duplication of AP services disperses the overall caseload, resulting in pathologist diagnostic acumen atrophy, excessive support personnel requirements, inadequate utilization of subspecialty expertise, and overall lower-quality patient care. Unlike many medical specialties, implementing AP services does not require direct patient interaction and is principally not as time-sensitive as other clinical laboratory testing. The practice of AP is conducive to a more consolidatory paradigm to achieve economies of scale. Pathology service unification would also afford the stationing of predominantly subspecialists at tertiary care centers to handle higher caseloads. Larger groups of pathologists increase patient safety enhancing peer-to-peer and subspeciality quality assurance processes during case review. Conversely, the nature of clinical pathology services requires a more widespread presence-even at the smaller, auxiliary clinics throughout the military health system. Clinical pathology services would also benefit from additional triservice cooperation including standardization of quality management processes, increased resource sharing, exchange, and cooperative contingency planning. Laboratory directorships also benefit from consolidating expertise, where pathologists could be physically located at a central site with remote oversight of laboratory services. Here, we propose a holistic triservice consolidation plan for military pathology to optimize resource utilization and ultimately realize the overarching strategic plan for military medicine set forth by the Defense Health Agency.

Prioritization Patterns of Nurses in the Management of a Patient With Delirium: Results of a Q-Methodology Study.

Nurses are required to decide on priorities; however, how they prioritize the interventions toward patients with delirium is still unclear. Therefore, expanding the knowledge on (a) how nurses prioritize interventions to manage episodes of delirium and (b) the underlying prioritization patterns were the aims of this study. The Q-methodology was applied in 2021. A systematic review to identify the recommended interventions for patients with delirium was performed, and a nominal group technique was used to select those interventions that are applicable in daily practice (35 out of 96 identified). Then, using a specific scenario, 56 clinical nurses working in hospital medical (n = 31), geriatric (n = 15), and postacute (n = 10) units were asked to order the 35 interventions (from -4 the lowest to +4 the highest priority) using a Q-sort table. Averages (confidence interval at 95%) were calculated at the group level, and a by-person factor analysis was applied to discover underlying patterns of prioritization at the overall and at the individual levels. At the group level, "Ensuring a safe environment (e.g., reducing bed height)" was ranked as the highest priority (2.29 out of four); at the individual level, three prioritization patterns accounting for a total variance of 50.21% have emerged: "Individual needs-oriented" (33.82% variance explained; 41 nurses); "Prevention-oriented" (8.47%; five nurses); and "Cognitive-oriented" (7.92%; six nurses). At the group level, nurses prioritize safety while caring for patients with delirium; however, at the individual level, they follow three different patterns of prioritization oriented toward diverse aspects, suggesting uncertainty in the actions to be taken-with potential implications for patients.

Variation in Structural Characteristics Among Twenty Medical-Psychiatry Units in the United States: A Survey-Based Study.

Medical Psychiatric Units (MPUs) are specialized hospital units providing integrated care for patients with co-occurring medical and psychiatric illnesses. Despite their growing relevance, data on their structural characteristics in the United States remain sparse. This study aims to inventory and analyze the structural characteristics of 20 US MPUs, categorizing them using Kathol's and Van Schijndel's frameworks, and identifying shared components to inform future MPU design and quality standards. A structured telephone survey was conducted with 20 MPUs from 15 states. Units were categorized as Medical Attending MPUs, Psychiatric Attending MPUs, or Co-Attending MPUs, based on physician involvement. Characteristics assessed included medical and psychiatric acuity capabilities, staffing, physical design, and diagnostic services. Data were analyzed for shared and variable characteristics, and findings were compared with prior studies. Most MPUs aligned with Kathol's Type III, characterized by medium to high medical and psychiatric acuity capabilities. Shared characteristics included integrated nursing practices, 24/7 diagnostic availability, and access to ICU-level care. However, significant variation existed in location, staffing, and technical capabilities. Most units were Psychiatry Attending or Co-attending MPUs. The US MPUs included primarily serve patients with medium to severe medical and psychiatric illnesses. Our findings highlight shared and variable features across MPUs, emphasizing the role of contextual needs and financial incentives in shaping their design. This study provides the most comprehensive inventory of US MPUs to date and proposes features to guide future MPU development and standardization.

Screening and Interpretation Rules for Resting Electrocardiograms in Polish Air Force Aircrew

INTRODUCTION: The resting 12-lead electrocardiogram (ECG) is one of the basic screening tests used in assessing fitness for military service and in periodic examinations of professional soldiers. Its purpose is to reduce the risk of death from cardiovascular disease by early detection of cardiac pathologies predisposing to sudden cardiac arrest. Commonly used electrocardiographic standards do not perform well in screening, accounting for the recognition of a large number of abnormalities unrelated to structural heart disease. METHODS: A comprehensive literature review was performed using electronic databases such as PubMed®, Google Scholar, and relevant aerospace medical journals. The search focused on keywords, including “screening ECG,” “electrocardiographic criteria,” “military aircrew,” and “aviation medicine.” Articles that discussed ECG interpretation rules and the implementation of screening protocols in military aircrew were included. The review also involved an examination of guidelines and policies from major aviation regulatory bodies. RESULTS: This review includes information on topics relevant to the application of 12-lead ECG in screening diagnostics, such as general ECG interpretation criteria, limitations of ECG as a screening tool, objectives of ECG-based screening, and past experiences with the use of screening ECG in athletes within the context of military medicine. DISCUSSION: We discuss various criteria for the interpretation of screening ECG in athletes and soldiers to increase the specificity of this test. We also present a proposal for a system of criteria for interpreting ECGs in aircrew of the Polish Air Force, which may help improve the detection of cardiac pathologies in this professional group. Kurek MA, Rola M. Screening and interpretation rules for resting electrocardiograms in Polish Air Force aircrew. Aerosp Med Hum Perform. 2025; 96(2):135–142.

Experiences of Birthing Individuals Receiving Perinatal Behavioral Health Care in the Military Health System and Civilian Care With TRICARE Insurance

OBJECTIVE: To explore birthing individuals' experiences of mental health care in the Military Health System or through TRICARE insurance. METHODS: We conducted a qualitative study. This was an IRB-approved protocol for individuals who delivered within the previous 5 years at military treatment facilities or with TRICARE insurance at civilian hospitals and were recruited for semi-structured qualitative interviews from February 2023 to June 2023. Interviews focused on participants' experiences of care during pregnancy, delivery, and the postpartum period. Purposive and snowball sampling was used to ensure diverse participation. Interviews were recorded and transcribed with deductive coding, and themes were identified until saturation was reached. RESULTS: Thirty-one individuals completed interviews, with 12 main themes identified: importance of support from their obstetric clinician and colleagues, importance of mental health check-ins during pregnancy, challenges accessing care, feelings of dismissiveness regarding mental health needs, inadequate assessment of symptoms, curtailing of symptoms and situational stress, lack of postpartum care, waiting extended periods for postpartum visits, privacy concerns leading to the concealment of symptoms to avoid documentation, concern for the adverse effect on careers, and support from doulas and support groups postpartum. A common theme included the need to improve screening for depression and anxiety. CONCLUSION: These results indicate varied perinatal mental health care experiences. Some individuals had supportive care, whereas others experienced delays and challenges accessing care despite having universal insurance. Opportunities to improve perinatal behavioral health care include timely access and expanding support programs.

Menopausal hormone therapy use among active duty service women.

Menopausal hormone therapy (HT) has been shown to be effective in alleviating symptoms of menopause. While previous literature has described the frequency of HT use for the relief of menopausal symptoms in both the general and veteran female populations, there is currently no literature describing this frequency within the female active duty population. This study aims to address this gap in knowledge by conducting a retrospective cross-sectional study of HT receipt in active duty service women (ADSW) ages 45 to 64 during fiscal years (FYs) 2018 to 2022. We used the Military Health System (MHS) Data Repository (MDR) to conduct a retrospective study of ADSW ages 45 to 64 in the US Army, Air Force, Navy, and Marine Corps during FY 2018 to 2022. Study analyses included descriptive statistics on participant demographics and HT type. Logistic regressions were performed to assess for significant associations between participant demographics and receipt of HT. We identified a total of 13,629 women aged 45 to 64 on active duty service in the US Army, Air Force, Navy, and Marine Corps during FY 2018 to 2022, of whom 1,290 (9.5%) received HT. Significantly lower odds for receipt of HT was observed among ADSW ages 45 to 49, 60 to 64, of Asian/Pacific Islander race, and all ranks below Senior Officer. No significant associations were observed by Service branch. The prevalence of HT use among ADSW ages 45 to 65 is lower than HT use among the US veteran population age 45 and older but higher than among the US general population age 45 and older.

Single Isolated Umbilical Artery in A Healthy Newborn: Case Report

Introduction: The umbilical cord (UC) typically contains two arteries and one vein. The presence of a single umbilical artery (SUA) is the most common anomaly associated with the umbilical cord and is linked to various congenital conditions. However, SUA can also appear as an isolated condition (ISUA), occurring without any accompanying fetal structural or chromosomal abnormalities. Clinical case: The case involves a 37-year-old primiparous patient with inadequate prenatal care. She presents to our medical unit for the first time at 38.2 weeks of pregnancy, experiencing latent phase labor and presentation dystocia. The patient has been diagnosed with SUA since 21.5 weeks of gestation. The pregnancy was resolved through an abdominal delivery, resulting in the birth of a healthy newborn. Discussion: Pregnancies involving fetuses with SUA are associated with an increased risk of various malformations, including renal, cardiac, nervous system, and gastrointestinal issues. These pregnancies may also lead to complications such as a small fetus for its gestational age, fetal growth restriction, abortion, preterm birth, and perinatal death. However, as illustrated in this case, SUA can occur without resulting in any adverse perinatal outcomes.

P-1980. Decoding the Complexity of Post COVID Conditions: Transcriptomic Analyses of Machine-Learning-Based Chronic Symptom Phenotypes

Abstract Background Post-COVID conditions (PCC, ‘Long COVID’) remain a military health concern, and symptom heterogeneity limits understanding of PCC pathogenesis. To address this, we used machine learning to define PCC phenotypes in Military Health System (MHS) beneficiaries. Here, we extend these findings to identify early transcriptomic profiles which may predict the development of these distinct symptom-based PCC phenotypes. (A) Machine learning techniques identified three groups of participants based on chronic symptom-clustering. Radial charts display the distribution of post-COVID condition (PCC) symptoms. Each plot’s axes represent different symptoms, with the length of each spoke indicating symptom prevalence. Shorter spokes indicate lower prevalence, while longer spokes indicate higher prevalence. (B) Clinical and demographic characteristics of 154 military health system beneficiaries by identified symptom-clusters. (C) Schematic representation of pathway enrichment analysis using the differentially expressed signature and pathway databases. (D-E) Jaccard similarity analysis identifies the similarity of leading-edge pathways within each symptom-cluster phenotype, with a result close to 1 indicating high similarity and close to 0 indicating significant differences. (F) Network analysis depicts pathway interactions between each symptom-cluster phenotype, with larger nodes representing clusters and smaller nodes indicating individual pathways. Grey lines indicate associations between clusters and pathways, revealing both overlapping and distinct pathway sets. Upregulated and downregulated pathways are highlighted in red and blue, respectively. (G) Non-overlapping leading-edge pathways are identified, with the size of each pathway node corresponding to the normalized enrichment score (NES), with an upward arrow and red color indicates upregulation, while a downward arrow and blue color denotes downregulation. Methods The EPICC cohort study evaluates SARS-CoV-2 infection in MHS beneficiaries. PCC phenotypes were identified using symptom data; transcriptome profiling was performed on early post-infection blood samples from participants who did and did not develop 3-month symptom PCC phenotypes. Participants with pre-COVID comorbidities were excluded to delineate gene responses for PCC from pre-existing illnesses. Comparison of transcriptomic signatures associated with symptom clusters involved utilizing Reactome, KEGG, BioCarta, and Hallmark pathway enrichment analysis. Hypergeometric p-values and the Jaccard coefficient (JC) assess pathway distinctiveness between symptom clusters and those with no PCC. Results We analyzed 154 participants with no reported comorbidities (Fig. 1), who completed a symptom survey 3-months after a SARS-CoV-2 positive test, and who had an early blood sample (median: 36 days post-infection). Clustering analysis stratified 3 distinct PCC symptom clusters: Sensory, Fatigue/difficulty thinking, and Difficulty breathing/exercise intolerance. Transcriptomic analysis noted post-infection signatures which predicted the development of each cluster (JC: 0.18–0.28). Leading-edge pathways included cytokine signaling in the Sensory cluster (Normalized Enrichment Score, NES=16.16, P < 0.001), nervous system development in the Fatigue/difficulty thinking cluster (NES=10.23, P < 0.001), and MYC Targets V1 in the Difficulty thinking/exercise intolerance cluster (NES=8.89, P < 0.001). Conclusion Distinct symptom-based PCC phenotypes are associated with different early post-infection gene expression pathways. These findings inform mechanistic hypotheses and the development of PCC prediction tools. These methods may be applied for prediction of post-acute sequelae in other pathogens. Disclosures Timothy Burgess, MD, MPH, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response Simon Pollett, MBBS, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response

P-1601. Reducing Inappropriate Cytomegalovirus and Hepatitis Genotype Testing with Diagnostic Stewardship

Abstract Background Over testing is a common problem that impacts patient safety and quality. Less frequent, yet expensive tests, such as CMV, HBV, and HCV resistance testing are frequently ordered inappropriately. Inappropriate ordering of these tests can lead to waste (unused test), false positives, unnecessary cost. Diagnostic stewardship promotes the judicious use of tests to enhance patient care and curb unnecessary expenses.Table 1:Summary Inappropriate/Total # of tests per Medical unit and Campus Number of inappropriate vs total number of orders per unit and campus during 2022 (retrospective data) Methods We performed a Quality improvement study (IRB exempt) from 12/2023 – 4/2024 using iterative PDSA cycles and compared data to 2022 baseline data. An interdisciplinary team conducted prospective review of all CMV, HBV, and HCV resistance tests at 2 NYC hospitals to determine appropriateness using established IDSA and AGA guidelines. All specimens were stored for up to 72 hours during review which included outreach to ordering providers when chart indication was not clear. Only providers cancelled tests if they agreed on inappropriateness. Baseline data were assessed for appropriateness using only patient charts.Table 2:Reasons for Inappropriate TestingSummary of Reasons for Inappropriate Testing during retrospective review Results We reviewed 240 tests in the baseline period and 33 tests to date in the intervention period. Of the baseline period, 73% met inappropriateness definition. (Table 1) Reasons for inappropriate testing are shown in Table 2. With prospective review, 18/33 tests met definition of inappropriate, of which 12/18 were cancelled by providers, (Figure 1) with reduction in inappropriate testing to 28% (Figure 2).Figure 1:Summary of Prospective Audit and Feedback ordersSummary of the total number of appropriate vs inappropriate genotype orders during prospective review Conclusion In this QI project with prospective audit and feedback, we were successful in reducing inappropriate resistance testing. Based on the pattern of inappropriate testing, multiple opportunities for sustained interventions were uncovered including clinical decision support to reduce duplicate testing and need for reflex testing.Figure 2:Run chart of Rate of Inappropriate test orders (Retrrospective and Prospective data)Rate of inappropriate test orders during retrospective review (72.5%) vs prospective review (28.6%) Disclosures Sonal Kumar, MD, Cymabay: Advisor/Consultant|Gilead Sciences: Honoraria|Ipsen: Advisor/Consultant|Madrigal Pharmaceuticals: Grant/Research Support|Madrigal Pharmaceuticals: Honoraria|Novo Nordisk: Advisor/Consultant|Novo Nordisk: Honoraria Lars Westblade, PhD, Accelerate Diagnostics, Inc: Grant/Research Support|bioMerieux, Inc: Grant/Research Support|Element Materials Technology: Grant/Research Support|Hardy Diagnostics: Grant/Research Support|Roche Molecular Systems, Inc.: Advisor/Consultant|Roche Molecular Systems, Inc.: Grant/Research Support|Selux Diagnostics, Inc.: Grant/Research Support|Shionogi, Inc: Advisor/Consultant|Talis Biomedical: Advisor/Consultant

P-46. A Comparative Analysis of Vaccine Uptake in Face-to-Face vs. Virtual Care for Active Duty Air Force Members Living with HIV

Abstract Background Military regulation requires US Air Force (USAF) members living with HIV receive Infectious Disease evaluation at the Medical Evaluation Unit (MEU). With a worldwide distribution of the USAF, telehealth utilization began in 2020 with improvements in clinical outcomes and decreased costs. However, not all facets of care are easily amenable to telehealth. We aimed to review differences in vaccination rates since transition from face to face (F) to virtual (V) visits. Methods All USAF active-duty members with incident HIV diagnosis between 2018 and 2023 were included. Only airmen stationed local to the MEU were evaluated F after 2020. Demographic, and clinical information was compiled. Vaccines of interest were selected according to current guidelines: human papilloma virus (HPV), meningococcal ACWY, pneumococcal, recombinant zoster and Mpox vaccines. Vaccine completion rates and time from HIV diagnosis to first vaccine dose was compared between groups. Results All 108 patients were male. Forty-four percent of visits occurred F and 56% were V. Median age was similar, 27 years for F and 26 years for V (p=0.84). Overall, demographics were not significantly different between groups (Table 1). Initial CD4 count was lower among those who received V care (472 vs 567; p=0.01). It took longer for patients to receive their first vaccine dose with V visits compared to F visits (99 vs 3 days; p< 0.01) (Table 2). Likewise, days from HIV diagnosis to first dose of vaccine administration was longer with V visits compared to F (134 vs 36; p< 0.01). Vaccine completion rates varied by type. Pneumococcal and HPV completion rates were higher in the F group compared with V group (p=0.02). Completion rates of the meningococcal ACWY primary series were similarly higher in the V group 92% vs 55%; p=< 0.001). Mpox completion rates were higher with F visits but not statistically significant (8% vs 3%; p=0.4). Recombinant zoster vaccine completion rates were nearly identical (22% vs 23%; p=0.96). Conclusion Vaccination rates were lower and took longer among USAF personnel who underwent V visits compared to F. As healthcare systems increasingly employ telehealth, future studies should investigate provider and patient attitudes on vaccine counseling during V visits to ensure the delivery of high-quality care in the virtual era. Disclosures All Authors: No reported disclosures

P-486. Current Trends in Hospitalization Among People Living with HIV at an Inner City Hospital in Newark, N.J

Abstract Background As HIV disease is becoming a chronic outpatient condition, we were interested in understanding what is driving high-cost hospitalization in people living with HIV (PLWH) at our inner city hospital in Newark, New Jersey. We sought to examine the trends in admissions over the last two years.Table 1compares the causes of hospitalization between 2022 and 2023 [n = 110] Methods A retrospective study was performed on electronic medical records of PLWH >18 years old admitted for at least 24 hours to the medical, intensive care, or psychiatry unit of Saint Michael's Medical Center from 2022-2023. The reason for hospitalization was determined to be the main diagnosis related to the symptoms on admission upon chart review. We calculated the standardized mortality ratios using observed deaths and expected deaths compared to mortality in the general inpatient population. We used R software to compare the causes of hospitalization between the two years using the Welch two-sample t-test.Figure 1demonstrates the breakdown of causes by infectious diseases over the 2 years Results We identified 110 HIV-positive adults admitted to the hospital. The mean age was 55.8 +/- 12.7 in 2022 and 53.6 +/- 16.3 in 2023. The causes of hospitalization are illustrated in Table 1, p=0.2438. Infections were the top cause of admissions with the most common infections from the respiratory system over two years as demonstrated in Figure 1. AIDS-defining infections were only 4.5% with a decreasing trend during the study period. Overall inpatient mortality in PLWH was 10% in 2022 and 7.14% in 2023. The mortality rate decreased from 4.06 (95% CI 2.20 - 6.91) in 2022 to 1.91 (95% CI 0.89 - 4.06) in 2023. The length of stay (LOS) among PLWH was 26% shorter than the LOS of the general inpatient population in 2022 (n = 4.475) and the same in 2023 (n = 5.34). The mean LOS in PLWH increased by 19.32% over the two years. Conclusion Infections are the most common cause of hospitalization in PLWH with stable trends over the last two years. Average mortality rates and length of stay were lower in PLWH compared to the general hospital admissions. Disclosures Jihad Slim, MD, FACP, AbbVie: Grant/Research Support|AbbVie: Honoraria|AbbVie: Speaker Bureau|Gilead Sciences, Inc.: Grant/Research Support|Gilead Sciences, Inc.: Honoraria|Gilead Sciences, Inc.: Speaker Bureau|Merck: Grant/Research Support|Merck: Honoraria|Merck: Speaker Bureau|Theratechnologies: Advisor/Consultant|Theratechnologies: Honoraria|ViiV Healthcare: Advisor/Consultant|ViiV Healthcare: Grant/Research Support|ViiV Healthcare: Speaker Bureau

P-1717. Perception and Practice of Physicians' Antibiotic Use at Tertiary Military Hospitals in Bangladesh

Abstract Background Inappropriate use of antibiotics, which contributes to increased antimicrobial resistance (AMR), is common in healthcare settings across the globe, especially in low-resources settings. Antibiotics are widely and inappropriately used without adherence to international guidelines in Bangladesh, which may contribute significantly to the development AMR. Military hospitals are known for better compliance of health care system. We sought to investigate the perceptions of Physicians of Tertiary military hospitals in Bangladesh regarding appropriate antibiotic use and prescribing approach. Physicians' AMR perception Methods We conducted a cross-sectional survey using a semi-structured questionnaire and data collected through face to face interview from 84 Military doctors of two major tertiary military hospitals of Bangladesh – Combined Military hospital (CMH) Dhaka (1650 bedded) and Jashore (500 bedded) between September 2020 and January 2021. Descriptive statistics were performed to analyze the data and for interpretation Approach of physician to prescribing antibiotic Results Out of 84 respondents, 70% of the physicians considered AMR is a significant concern worldwide, but only 26.7% Physician of Dhaka CMH and 11% of Jashore CMH considered it as a problem in their hospital. Two-third respondent (66%) considered that inappropriate use of antibiotic is the main cause of rising AMR, followed by Over prescription of broad-spectrum antibiotics by 62.2%, and Easy access to antibiotics without a prescription by 58.8%. Around 36.2% opined that poor IPC practices by health professionals are also important factor. Total 72.6% respondent ensure that they routinely step down I/V antibiotics to oral antibiotics as earliest, 13.4% physicians considered cost affordability of the patient affects their choice of antibiotics. Over half of the physicians (51.2%) use prophylactic antibiotic for 3 to 7 days after any surgical procedure of a clean-contaminated case without signs of infection, where only 7.3% doctor use single dose antibiotic prophylaxis. Use of antibiotic prophylaxis in surgical procedure Conclusion Physicians' perception on AMR and rational antibiotic prescription were found fall of short of the standard. Strict compliance of antibiotic use and trade guideline, Introduction of formal antibiotic stewardship program in Bangladesh may be a useful intervention Disclosures All Authors: No reported disclosures

P-1935. Proteomic and transcriptomic signatures of SARS-CoV-2 associated myocarditis

Abstract Background SARS-CoV-2 myocarditis is a rare but serious complication of COVID-19. The host response correlates of SARS-CoV-2 myocarditis remain unclear, thereby limiting therapeutic development. We therefore performed proteomic and transcriptomic phenotyping of SARS-CoV-2 myocarditis in Military Health System (MHS) beneficiaries. We included a bioenergetics focus given the emerging role of mitochondrial function in enteroviral myocarditis. Early (<30 days post infection) plasma proteomic biomarkers measured by the Ella 20-plex ELISA assay in cases (SARS-CoV-2 infections with myocarditis) versus controls (SARS-CoV-2 infections without myocarditis). Values are log10 transformed, and p-values are adjusted for multiple comparisons across the full twenty biomarkers (six shown here; * indicates a p-value < 0.05). CRP = C-Reactive Protein; IFNG = Interferon Gamma ; PCT= Procalcitonin; TNFR1 = Tumor necrosis factor receptor-1; DDIMER = D-dimer; and IL1RA = Interleukin-1 receptor antagonist. Methods We previously adjudicated five unvaccinated pre-Delta SARS-CoV-2 myocarditis cases among 5265 MHS beneficiaries who enrolled into the EPICC study with COVID-19; four of these cases had blood collected. We matched myocarditis cases 1:10 with sex, age, comorbidity, and blood sampling-time matched controls (SARS-CoV-2 infection with no myocarditis) from the EPICC study. Cases and controls underwent comparison of early (< 30 days post infection) plasma proteomic biomarkers measured by the Ella 20-plex ELISA assay (with multiplicity adjustment). We also performed early whole blood transcriptomic sequencing with DESeq2 and GSEA analysis of custom mitochondrial pathways, including mitochondrial (mtDNA) regulated innate immune pathways (with FDR for multiple comparisons). Gene set enrichment analysis of custom mitochondrial pathways in cases (SARS-CoV-2 infections with myocarditis) versus controls (SARS-CoV-2 infections without myocarditis). FDR = False Discovery Rate; NES = Normalized enrichment score. Results We detected higher post-infection Tumor Necrosis Factor Receptor-1 (TNFR1) and procalcitonin (PCT) plasma concentrations in myocarditis cases versus matched controls (TNFR1: 0.33 log10 pg/mL difference, p = 0.032; PCT: 0.59 log10 pg/mL difference, p = 0.02) (Fig 1). We noted no statistically significant difference in the 18 other proteomic markers tested. GSEA analysis noted upregulated mitochondrial central dogma and OXPHOS pathway genes, and downregulated mtDNA innate immune genes, in cases versus controls (FDR < 0.05) (Fig 2). Conclusion In this MHS study, SARS-CoV-2 myocarditis was associated with elevation of TNFR1 and PCT secretion, upregulated mitochondrial central dogma and OXPHOS gene expression, and downregulated mtDNA innate immunity. While constrained by small sample sizes of a rare complication, these biomarker associations prompt mechanistic studies which may direct development of therapies for myocarditis due to SARS-CoV-2 and perhaps other respiratory viral pathogens. Disclosures Simon Pollett, MBBS, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response David Tribble, MD, DrPH, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response Timothy Burgess, MD, MPH, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response

P-1936. Does SARS-CoV-2 Infection or Vaccination Impact Menstrual Health? Results From a Longitudinal Cohort Study Among Military Health System Beneficiaries

Abstract Background The impact of SARS-CoV-2 infection and vaccination on menstruation is unclear. The goal of this study is to quantify the relationships between history of SARS-CoV-2 vaccination and infection and incident, clinically documented menstrual irregularities using data from the EPICC study in Military Health System (MHS) beneficiaries.Figure 1.Odds of menstrual irregularities associated with having been infected with or vaccinated against SARS-CoV-2 in certain timeframes (30, 90, 180, and 365 days prior to diagnosis or matched timepoint), after controlling for comorbidities in cases and controls matched on race/ethnicity, five-year age group, and BMI category in the Epidemiology, Immunology, and Clinical Characteristics of emerging infectious diseases with pandemic potential (EPICC) cohort. Methods This study included 18–50-year-old women who did not have pre-specified characteristics (e.g., pregnancy, breastfeeding, menopause) or pre-existing diagnoses of menstrual irregularities prior to the pandemic in their electronic medical record (MHS Data Repository (MDR)). Cases had a new diagnosis of a menstrual irregularity in the MDR between 3/2020 and 12/2022 and were matched 1:1 with a control of the same race/ethnicity, BMI category, and age category who did not have a menstrual irregularity diagnosis during that same time. Proportions with/without a history of SARS-CoV-2 infection and/or vaccination were compared. A logistic regression model provided estimates of the associations between SARS-CoV-2 infection or vaccination (in 30-, 90-, 180- or 365-days prior to diagnosis or matched timepoint) and diagnosis of menstrual irregularities.Table 1.Matched characteristics in those with and without menstrual irregularities in EPICC (N=249 cases, 249 controls) Results There were 270 participants (out of 1,156 women) with incident clinically documented menstrual irregularities identified over 2.8 years (8.3% per year from 3/20 to 12/22). Based on individual matching, 249 cases and controls were included in analyses (N=498, 21 cases did not have a matched control and were dropped) (Tables 1 & 2). Fewer controls than cases had a positive SARS-CoV-2 test in the prior 30, 180, and 365 days, whereas more controls reported being vaccinated in all time periods, but these were not statistically different (p >0.2) (Table 3). No statistically significant associations between 30, 90, 180, or 365-day history of SARS-CoV-2 infection or vaccination and menstrual irregularities were identified (Figure 1).Table 2.Incident menstrual-associated irregularities reported in 249 EPICC participants1 - 11 (4.4%) of the participants had more than one diagnosis Conclusion No relationship between recent SARS-CoV-2 infection/vaccination and clinically attended menstrual irregularities was observed in this analysis, but further studies are needed to confirm these findings. Future work will include analyses based on each vaccination and infection event using Cox proportional hazards models.Table 3.Participants’ history of SARS-CoV-2 infection and vaccination among those with and without menstrual irregularities in EPICC. P-values generated using Pearson’s Chi-squared tests. Disclosures Ryan C. Maves, MD, AiCuris: Grant/Research Support|Biotest: Grant/Research Support|GeoVax: Grant/Research Support|Shionogi: Advisor/Consultant|Shionogi: Honoraria|Sound Pharmaceuticals: Grant/Research Support Mark Simons, PhD, Astrazeneca: Grant/Research Support Timothy Burgess, MD, MPH, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response Simon Pollett, MBBS, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response

P-174. Burden, Epidemiology, and Clinical Characteristics of Leptospirosis within the Military Health System

Abstract Background Leptospirosis (Lepto) remains underreported due to diagnostic limitations. Military personnel are considered high risk due to deployments in endemic locations and exposure in contaminated training sites. We analyzed the frequency, epidemiology, and clinical characteristics of lepto diagnoses in the Military Health System (MHS).Figure 1Leptospirosis Lab and Clinical Case Definitions and Criteria Methods Potential MHS lepto diagnoses were identified by lepto-specific ICD-9/10 codes or positive lepto laboratory tests between 1/1/2013-1/1/2022. Potential cases underwent chart review, were classified per CDC case definitions (Figure 1), and compared for clinical and lab findings.Figure 2Flowchart for Identification of Leptospirosis Cases Results Of 297 identified potential lepto cases, there were 11 confirmed, 134 probable, and 53 possible cases on chart review (Figure 2) of whom 77% (153/198) were hospitalized and one died (Table 1). Cases were confirmed via microscopic agglutination test (MAT, 6/11), blood culture (3/11), MAT and blood culture (1/11), and urine PCR (1/11) (Table 2). Of cases with demographic data, 89% were male (176/197) and 82% (162/197) were service members, with 16% (31/197) retired, dependents, or civilians. Of those with documented exposures, 52% (88/169) were recreational, and an additional 5 cases non-occupational (cumulatively 55%, 93/169). Fresh water exposures were common and more likely in confirmed/probable cases, with 67 associated with jungle warfare training in Okinawa. Of note, 44% of all cases (87/198) were diagnosed in those living in endemic areas without occupational exposure or deployment/travel. Japan (86/198), Guam (55/198), and Hawaii (22/198) were the most common areas of exposure. Confirmed cases were most likely to be exposed and diagnosed in Hawaii.Table 1Clinical Characteristics of Confirmed, Probable, and Possible Leptospirosis Cases Conclusion Lepto remains a common diagnosis within the MHS, especially among service members and in endemic areas. Despite classic teaching, a significant proportion of MHS cases occur in patients living in endemic areas without occupational or deployment exposures. This highlights lepto as a continual threat and burden on systems in endemic areas in addition to the classically recognized military exposures. Furthermore, despite a substantial amount of possible and probable cases, there remain few confirmed cases.Table 2Laboratory Testing of Confirmed, Probable, and Possible Leptospirosis Disclosures All Authors: No reported disclosures

P-151. Cutaneous Larva Migrans Within the United States Military Health System and Association with International Travel

Abstract Background Cutaneous larva migrans (CLM) is a parasitic dermatitis which occurs after zoonotic hookworm larva from the soil penetrate the skin. CLM is most common in tropical and sub-tropical regions of the world and in returning travelers from those regions. Within the United States (U.S.) autochthonous cases of CLM have been reported, however the epidemiology is not well-described. We seek to describe the epidemiology of CLM and association with geographic location and international travel within the U.S. military health system. Methods We performed a retrospective cohort study of active duty service members and their family members who had a diagnosis code of hookworm between October 2012 and September 2018. Of the initial cohort (n = 272), 61 (22.4%) were diagnosed with CLM. Results Most patients in this study were male (65.5%), active duty (55.7%), and white (45.9%) [Table 1]. Patients’ ages ranged from 1 to 56 years (mean 24.6) with 80.3% of patients 18 years of age or older. All the patients were born within the United States. Most were diagnosed by their primary care manager, however 19.7% were diagnosed via emergency or urgent care. Patients reported preceding travel to tropical and subtropical world regions in 32.8% of cases: Caribbean (13.1%), Africa (6.6%), Mexico and Central America (6.6%), South America (3.3%) and Japan (3.3%) [Figure 1]. After excluding those with preceding international travel, 67.2% of patients had autochthonous CLM. Of the autochthonous cases, more patients were diagnosed or had preceding travel in the southeast U.S. (68.3%) compared with the western U.S. (19.5%), southwest U.S. (9.8%), or northeast U.S. (2.4%) [Figure 2]. States with the highest number of cases were Florida (26.7%), Georgia (14.6%), North Carolina (9.8%), Texas (9.8%), Washington (7.3%) and Hawaii (7.3%). Based on the reported literature, we found a lower number of cases with preceding international travel than expected. Most autochthonous cases within the U.S. were from the southeast and coastal regions. Conclusion CLM should be considered in the U.S. even in patients without recent international travel. These findings are useful in providing nationwide data on the epidemiology of CLM and allowing for informed preventative counseling to travelers and non-travelers within the U.S. Disclosures Alison Helfrich, DO, MPH, Moderna: Stocks/Bonds (Public Company)|Sanofi: Stocks/Bonds (Public Company)

P-130. A Case-Control Study of Post-Infectious Sequelae Following a Shiga Toxin-Producing Escherichia coli (STEC) Outbreak at a U.S. Marine Corps Recruit Depot

Abstract Background In November 2017, an outbreak of Shiga toxin-producing Escherichia coli (STEC) O157:H7 and O26 occurred among male recruits at a United States Marine Corps Recruit Depot, San Diego, CA. We sought to evaluate the 6-year risk of hypertension (HTN), chronic kidney disease (CKD), and irritable bowel syndrome (IBS) following STEC infection by conducting a retrospective, case-control study utilizing medical record data.Table 1.Proportion of STEC cases and matched asymptomatic controls with post-infectious sequelae following November 2017 outbreak Methods Data from the outbreak investigation were used to identify cases and asymptomatic controls. Asymptomatic controls were recruits who were in the exposure area during the outbreak but remained asymptomatic and were negative for STEC by stool PCR. Cases were matched 1:4 with asymptomatic controls based on the duration of follow-up available in the Military Health System Data Repository (MDR). Controls could be matched to > 1 case. Post-infectious outcomes were assessed using ICD-10 diagnostic codes in the MDR. Results 239 cases were identified of whom 192 (80%) developed bloody diarrhea, 30 (13%) were hospitalized, and 17 (7%) developed hemolytic uremic syndrome (HUS). The stx-2 gene was detected in 39% of PCR positive cases. The median age of recruits was 19 years, and the median duration of MDR follow-up for cases and controls was 3.7 years (IQR: 2.9-5.4). There was no significant difference in the proportion of cases and controls with post-infectious sequelae (Table 1). Resolution of renal dysfunction was noted within 3 months after discharge for all HUS cases, and only 1 case remained hypertensive following discharge. There was no significant difference in the proportion of bloody diarrhea and HUS cases that developed IBS compared to controls. A limitation of the analyses was the short duration of MDR follow-up available for 6/30 hospitalized cases due to military separation after hospital discharge. Conclusion STEC infection in this cohort of young military recruits was associated with a good prognosis, even among cases of STEC-associated HUS, with resolution of renal dysfunction and no increase in incidence of IBS or HTN compared with asymptomatic controls. The findings suggest that STEC infection in young adults who recover from acute illness is not associated with a higher likelihood of post-infectious sequelae. Disclosures Ryan C. Maves, MD, AiCuris: Grant/Research Support|Biotest: Grant/Research Support|GeoVax: Grant/Research Support|Shionogi: Advisor/Consultant|Shionogi: Honoraria|Sound Pharmaceuticals: Grant/Research Support

P-724. The epidemiology, phenotype, and phylogeny of an influenza A/H3N2 virus outbreak among vaccinated U.S. Navy midshipmen

Abstract Background Characterizing influenza outbreaks among vaccinated populations may support optimization of influenza prevention. We used a surveillance study at the United States Naval Academy (USNA) to characterize the epidemiology, phenotype, and phylogeny of a recent influenza A/H3N2 outbreak among vaccinated midshipmen (undergraduate students). Figure 1 Figure 1A: Influenza A/H3N2 case counts among USNA Midshipmen and Staff Evaluated in February 2024. Day 1 refers to the collection time of the first influenza A/H3N2 outbreak clonal sequence. ‘Mitigation strategies implemented’ included case isolation, case masking, and contact chemoprophylaxis. Figure 1B: Estimated Rt (effective reproductive number) of influenza A/H3N2 virus cases in February 2024. Day 1 refers to the collection timing of first clonal influenza sequence. Methods “Acute Respiratory Infections at the Academy” (ARIA) is a study of medically attended ARIs (MAARIs) among USNA midshipmen and staff presenting to the Brigade Medical Unit for clinical care; the USNA comprises ≈ 4000 midshipmen. ARIA abstracts epidemiological, clinical and laboratory data from MAARIs. Residual clinical respiratory tract swabs also undergo multiplex PCR and sequencing of respiratory viruses, including influenza viruses. Demographic, Clinical and Viral Characteristics of Influenza A/H3N2 Positive Cases Results An outbreak of influenza A/H3N2 emerged in February 2024, with declining cases and Rt following mitigation strategies (case masking, isolation, and post-exposure oseltamivir; Fig 1). A total of 87 A/H3N2 cases were recorded, predominantly in midshipmen. HA sequence data from 83 cases confirmed local clonal transmission (3C.2a1b.2a.2a.3a.1 clade), consistent with early Rt estimates (Fig 1, Fig 2). The median age of cases was 20 years and 90% received 2023/2024 Northern Hemisphere influenza vaccine (99% egg-based inactivated influenza vaccine) by October of 2023. Over half (55%) of cases were treated with oseltamivir, and no evidence of antiviral resistance was detected. No cases were hospitalized, and the median sick-in-quarters time was 3 days (Table 1). Phylogenetic analysis did not indicate major genetic divergence from the 2023-2024 Northern Hemisphere vaccine A/H3N2 HA sequence (Fig 3). Time-scaled phylogeny of influenza A/H3N2 HA segment genes sequenced from ARIA (red branches) with context background sequences from GISAID. Phylogenetic tree inferred by IQTree and visualized in Auspice using the NextStrain environment. Inset A captures the diversity of 2a.3a.1 influenza cases involved in this outbreak investigation. Inset B shows the largest cluster of cases (n=58) with identical HA gene sequences. The 2023-2024 Northern Hemisphere vaccine strain sequences are indicated. Clade numbers are annotated by color. Conclusion Influenza A/H3N2 outbreaks can be impactful in vaccinated congregate populations; further analysis is in progress to identify strain antigenicity markers which may have contributed to this outbreak and predict other outbreaks. Non-pharmaceutical countermeasures and chemoprophylaxis appeared effective in mitigating this outbreak. Our findings highlight the importance of further research into universal influenza vaccines, alternative vaccine dosing regimens, and optimal chemoprophylaxis strategies to prevent such outbreaks. Disclosures Simon Pollett, MBBS, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response Timothy Burgess, MD, MPH, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response

Sex Differences in Early/Unplanned Separation Among US Service Members With a History of Mild Traumatic Brain Injury.

To investigate the incidence of early/unplanned (E/U) separations following mild traumatic brain injury (mTBI) and assess whether sex impacts the hazard of separation. Military Health System (MHS). Active duty service members (N=75,730) with an initial mTBI diagnosis in military records between January 2011 and January 2018. Retrospective cohort study of electronic health records in the MHS. Cause-specific Cox proportional hazards models were used with sex at birth as the primary predictor. Early/unplanned (E/U) separation, defined as military separation attributed to disability, misconduct, poor performance, death, or other medical circumstances, within 2 years following the initial mTBI. Incidence of E/U separation within 2 years following mTBI was 13.7% (11.0% in women and 14.2% in men). Disability and misconduct separations were most common. Female service members had lower adjusted hazards for any E/U separation (Hazard Ratio [HR]=0.65; 95% Confidence Interval [CI]: 0.61,0.69), disability separation (HR=0.71; 95% CI: 0.65, 0.78), misconduct separation (HR=0.40; 95% CI: 0.36, 0.45), and poor performance separation (HR=0.84; 95% CI: 0.72, 0.99), compared to males, but had higher adjusted hazards for separations due to other medical circumstances (HR=1.24; 95% CI: 1.04, 1.48). Male and female service members had different hazards of E/U separation following mTBI. Separating early may increase the risk of adverse health and socioeconomic outcomes, so additional research is needed on why these separations occur and why they may be impacting men and women differently.