Extracorporeal membrane oxygenation (ECMO) for infectious causes of refractory cardiopulmonary failure is established as appropriate therapy in high-income countries. Its use in low- and middle-income nations for tropical infections is not well-studied, however, perhaps because most of these countries have not been historically able to offer ECMO support. Tropical infections remain an important cause of global morbidity and mortality, but the role of ECMO is poorly described. We identified a list of viral, bacterial, fungal, and parasitic infections that qualified as tropical infectious diseases. These included infections that were either a World Health Organization (WHO) designated Neglected Tropical Disease (NTD) or an infectious disease with a higher prevalence in the Tropics than elsewhere. We conducted a comprehensive review of existing literature regarding ECMO use to support these infections. Multiple viral, bacterial, fungal, and parasitic tropical infections have been supported by ECMO with varying success. leptospirosis, melioidosis, and tuberculosis are conditions suitable for venovenous ECMO support with frequent use in the literature and reported survival as high as 84

BACKGROUND:Babesia microti is a transfusion-transmitted pathogen. The US Food and Drug Administration (FDA) recommends blood donor screening only in endemic states, whereas the Military Health System performs universal Babesia screening regardless of geographic location. However, the epidemiology of Babesia positivity and clinical follow-up among blood donors in non-endemic regions remains poorly characterized. STUDY DESIGN AND METHODS:We conducted a retrospective study evaluating Babesia screening results from three military blood donation centers in non-endemic states: Naval Base San Diego, Wright-Patterson Air Force Base, and Joint Base San Antonio-Lackland. All donations collected between January 1, 2021 and December 31, 2025 underwent nucleic acid testing using the Procleix Babesia Assay. Positive donors underwent retrospective chart review to assess demographics, confirmatory testing, clinical follow-up, and treatment outcomes. RESULTS:Among 97,861 donations screened, eight donors tested positive for Babesia (8.17 per 100,000 donations). San Diego demonstrated the highest positivity rate (11.53 per 100,000), followed by Wright-Patterson (8.55 per 100,000) and San Antonio (5.82 per 100,000). Five donors were active-duty military personnel with medical records available for review, and three underwent follow-up clinical evaluation. Follow-up approaches varied considerably and include empiric treatment without confirmatory testing, antibody testing, peripheral blood smear evaluation, and polymerase chain reaction (PCR) testing. All clinically evaluated donors were asymptomatic, and there were no documented complications related to babesiosis. DISCUSSION:Babesia positivity among military blood donors in non-endemic regions was rare. Variation in diagnostic evaluation and clinical management highlights the need for standardized follow-up protocols for military donors with positive screening results.

Nosocomial infections are common in patients receiving extracorporeal membrane oxygenation (ECMO), with ECMO cannula-site infections (ECMO-CSI) being the most frequent infections directly related to the ECMO run. These infections can significantly impact patient outcomes. Currently, no adult guidelines exist for the prevention, diagnosis, and/or treatment of peripheral ECMO-CSI, resulting in heterogeneity in both clinical practice and research findings. We conducted a Delphi study involving 39 international experts in ECMO management. The experts participated in four Delphi rounds to reach consensus on various aspects of ECMO-CSI complicating peripheral ECMO (central ECMO excluded), including definition, clinical suspicion, diagnostic methods, preventive measures, and treatment. Consensus was defined as ≥ 70

INTRODUCTION:The impact of Chagas disease in the United States military is unknown. While previous studies have suggested a low number of cases, current testing practices are uncharacterized. This study evaluates the current testing practices for Chagas disease at a large military base in South Texas. MATERIALS AND METHODS:The electronic health record was queried to identify tests for Chagas disease performed at Joint Base San Antonio between January 2022 and August 2024. For those patients tested, charts were reviewed to document patient factors as well as clinical factors associated with testing. RESULTS:During the study period, 75 patients were tested for Chagas disease, with 9 (12%) performed on active-duty military personnel. Most patients tested were male (75%) and received care in the outpatient setting (72%). Testing was primarily done due to concern for Chagas cardiomyopathy (45%) or as a screening test before bone marrow transplantation (38%). Risk factors were only documented for 27 (36%) patients with a test and varied by the specialty ordering the test. Four (5%) patients had an initial positive test, but only one (25%), who was tested before bone marrow transplantation, had confirmed infection. CONCLUSIONS:This study demonstrates that current testing practices at Joint Base San Antonio do not target patients with a high pretest probability of Chagas disease. Efforts should be made to prioritize testing in those at increased risk in the Military Health System to determine the true burden of this infection.

Introduction Hospital - acquired pneumonia (HAP) and ventilator - associated pneumonia (VAP) represent a significant healthcare burden with increased mortality among critically ill patients. Unfortunately, universal definitions and established clinical characteristics remain debated, especially in patients receiving extracorporeal membrane oxygenation (ECMO) support for cardiopulmonary failure. This study evaluates factors associated with respiratory culture positivity in patients receiving ECMO.Methods In this single - center retrospective cohort of adult patients receiving ECMO between January 2022 and June 2024; we evaluated clinical parameters and patient factors associated with suspected HAP/VAP, defined as a new positive respiratory culture with clinical characteristics of infection. Additionally, isolated organisms were assessed for persistent positivity.Results Among the 88 samples collected from 35 patients, no clinical or laboratory differences were identified when comparing samples with positive organisms recovered vs negative culture growth. ECMO-associated HAP/VAP incidence rate was 18.7 per 1000 ECMO - days. Recovered pathogens were primarily from the Enterobacteriaceae family or Pseudomonas aeruginosa at 33.3% and 27.8% respectively. Only 27.3% of patients who met criteria for HAP/VAP had evidence of radiographic changes. A minority of HAP/VAPs (27.3%) had microbiologic cure after treatment completion and no patient cleared Burkholderia cepacia, Staphylococcus aureus, or Stenotrophomonas maltophilia in this cohort.Conclusion Timely diagnosis and management of HAP/VAP is essential in the care of the critically ill. However, clear incidence rates and diagnostic accuracy has been hindered by heterogenous definitions and poor sensitivity/specificity of clinical indicators. The need for a unified diagnostic criteria are amplified in ECMO where clinical management is confounded by a persistent proinflammatory state and frequent respiratory tract colonization.

In this retrospective cohort study at a quaternary referral hospital, 829 adult patients supported by extracorporeal membrane oxygenation (ECMO) between January 1, 2014, and October 31, 2024, were screened for ventilator-associated pneumonia (VAP). The incidence of VAP in ECMO-supported patients was 17.7 per 1,000 ECMO days (venoarterial [VA] ECMO, 22.1 per 1,000 ECMO days; venovenous [VV] ECMO, 13.8 per 1,000 ECMO days). Median time from ECMO cannulation to diagnosis of VAP was 4 (interquartile range [IQR], 3-8; range 1-84) days. Gram-negative bacteria comprised most respiratory pathogens. A significant increase in minimum ECMO sweep was noted from 2 days before to 1 day after VAP diagnosis (0.79 L/min increase, p = 0.004). Only 38 of 153 patients (24.8%) met National Healthcare Safety Network (NHSN) VAP definitions. After creating a modified VAP definition, which included an ECMO sweep increase of 0.5 L/min as evidence of worsening respiratory status, 78 (51.0%) met the modified definition. Those who met the modified VAP definition had worse in-hospital (60.3% vs. 28.0%, p < 0.001), 30 day (33.3% vs. 17.3%, p = 0.023), and 90 day (53.8% vs. 25.3%, p < 0.001) mortality compared with those who did not meet the modified VAP definition. The incorporation of ECMO parameters into diagnostic criteria may improve detection sensitivity, but further validation is necessary before implementation.

Chagas disease, caused by Trypanosoma cruzi, poses an emerging and under recognized threat to U.S. military personnel deployed in endemic regions. Despite significant morbidity and mortality risks, the US Department of Defense (DoD) lacks comprehensive policies for Chagas disease prevention, screening, or treatment, unlike other similar infectious diseases. We conducted a comparative policy analysis of existing DoD policies on tuberculosis, HIV, and hepatitis C to inform the development of Chagas disease policy. Using an adapted Political, Administrative, Social, Technological, Economic, Legal factors (PASTEL) framework, we evaluated five policy alternatives through expert consensus scoring. Military health policies and literature were systematically reviewed to identify screening protocols, risk assessment tools, and prevention strategies. Analysis of current military screening policies revealed significant gaps in Chagas disease coverage in comparison with analogous infectious diseases. The decision matrix analysis identified an integrated Periodic Health Assessment (PHA) approach as the optimal policy alternative (weighted score 4.20/5.0), followed by targeted risk-based screening (3.85/5.0). Universal screening scored lowest (2.20/5.0) due to poor cost-effectiveness and implementation challenges. The recommended approach leverages existing annual health assessment infrastructure while incorporating Chagas disease-specific risk evaluation tools. A tiered policy strategy integrating Chagas disease risk assessment into routine military health evaluations offers the most feasible approach for protecting service members. Implementation should prioritize risk-based screening, vector-control measures (e.g., insecticide-treated uniforms), and enhanced surveillance in endemic deployment areas. This framework provides an evidence-based foundation for developing comprehensive DoD Chagas disease policies.

Limited data on sexual networks in the U.S. military makes designing strategies to combat sexually transmitted infections (STIs) challenging. This retrospective evaluation assessed reported sexual networks of military service members with chlamydia, to inform future interventions for decreasing transmission of the infection. Thirty-two active duty service members at Joint Base San Antonio-Fort Sam Houston tested positive for chlamydia infection during the evaluation period, June through December 2023. Service members who tested positive for chlamydia were interviewed by Army Public Health Nursing staff and were asked to identify their sexual partners from the preceding 60 days, for routine contact tracing. Patient responses were then anonymized for comparisons of sexual networks of military service members-by sex, branch of service, and whether they were participating in military training or had completed training ("permanent party"). Service members with chlamydia were predominantly female (n=19, 59.4%), in the Army (n=18, 56.3%), and in military training (n=20, 62.5%). Of the 45 sexual contacts of the 32 service members identified through contact tracing, the majority (n=30, 66.7%) of those sexual contacts were civilians. Those still in military training were more likely to report sexual contacts who were also military service members, compared to permanent party service members (n=12, 50% vs. n=3, 14.3%, p=0.014). This evaluation determined that most service members who developed chlamydia were in sexual networks with only a single partner (n=22, 68.8%). These data should form an initial assessment of a military sexual network that needs to be confirmed in larger settings. This analysis of sexual networks at Joint Base San Antonio-Fort Sam Houston involving 32 military service members with chlamydia found that sexual networks for service members who were in training had a greater proportion of sexual partners who were also in the military compared to service members who were not in training (50% vs. 14.3%, p=0.014).

INTRODUCTION:Latent tuberculosis infection (LTBI) screening plays a vital role in global efforts to eliminate tuberculosis (TB). While LTBI treatment has been associated with lower rates of reactivation of TB and all military branches screening programs for LTBI screening, there is limited military data on factors associated with screening positivity and treatment completion. MATERIALS AND METHODS:This retrospective study examined positive Quantiferon-Plus (QFT-Plus) assays in the San Antonio Military Health System between January 2022 and June 2024. Electronic medical records were reviewed for information, including demographics, indications for testing, TB risk factors, deployment and travel history, quantitative QFT-Plus results, final diagnosis, and treatment course. QFT-Plus assays were considered false positive in patients with repeat tests that were negative. RESULTS:A total of 6,321 QFT-Plus assays were performed in the study period with 192 (3%) unique patients identified to have positive QFT-Plus assays. Ninety-seven (51%) patients were ultimately diagnosed with LTBI with most patients being active-duty military. The most common indication for testing was occupational screening, such as for health care workers. Patients with an initial greater TB-nil value were more likely to have true disease rather than a false positive (0.968 [0.52-3.5] vs. 0.435 [0.38-0.62], P = .0007). Of patients diagnosed with LTBI, a total of 58 (60%) initiated treatment and 41 (42%) had documented completion of treatment. Factors associated with incomplete treatment were use of an isoniazid-only regimen (n = 6, 60% non-completion rate) and reassignment to a new duty station after LTBI diagnosis (n = 11, 79% non-completion rate). CONCLUSIONS:This study offers a modern evaluation of LTBI screening in a military setting and provides targets for future interventions including those who change duty stations or use an isoniazid-based regimen. Military clinicians should be aware that patients with a low positive TB-nil on QFT-Plus assays are frequently false positive and require repeat testing.

While female U.S. Air Force and Space Force basic military trainees are screened universally for gonorrhea and chlamydia, male basic trainees are tested only when symptomatic or upon patient request. Epidemiology and follow-up testing of male basic trainees who test positive for gonorrhea or chlamydia in training is unclear. All active duty male basic trainees at Joint Base San Antonio-Lackland who tested positive for gonorrhea or chlamydia from 2017 through 2023 (50 of 182,726 total male trainees, 0.03%) were matched, 1-to-1, by age and accession date, with active duty female basic trainees who tested positive for the same pathogen. Medical records from military hospitals and clinics were reviewed for follow-up testing within 12 months of the initial positive test and subsequent diagnoses for chlamydia and gonorrhea up to 3 years afterwards, or July 1, 2024, whichever occurred first. Among 50 male basic trainees, 30 (60%) reported symptoms when presenting for testing. Most cases (86%) were due to chlamydia. Only 56% (n=28) of male trainees had follow-up testing within 1 year, compared to 76% (n=38) of matched female basic trainees (OR 0.4, 95% CI: 0.17, 0.95). Low screening for chlamydia and gonorrhea among male basic trainees may contribute to reduced follow-up testing and represents a missed opportunity to identify infections, prevent transmission, and reduce the burden of infection in this population. Male basic military trainees who tested positive for gonorrhea or chlamydia had follow-up testing rates significantly below guideline recommendations. Rates of future infections among male basic trainees were not, however, statistically lower than female trainee rates of future infections.

INTRODUCTION:The bacteria, Neisseria meningitidis, is a frequent colonizer of the oropharynx, but can also lead to invasive disease with encapsulated strains. All military services currently use a quadrivalent polysaccharide vaccine against serogroups A, C, W, and Y to prevent outbreaks among trainees. With the introduction of novel vaccines against serogroup B, this study evaluated the current carriage of N. meningitidis among military trainees. MATERIALS AND METHODS:Between June and August 2024, a sample of 909 military trainees received oropharyngeal sampling at the time of beginning basic military training before universal vaccination and penicillin administration. All isolates were serogrouped by polymerase chain reaction (PCR) and whole genome sequencing. This study was reviewed by the Lackland Institutional Review Board and determined to be occupational surveillance and not human research. RESULTS:Thirty-five (3.9%) trainees had carriage of N. meningitidis. While the PCR suggested, 11 (31%) isolates were encapsulated with Serogroup B, to be the most common colonizing isolate (n = 8, 22%). However, when characterized by whole genome sequencing, only one isolate, expressing serogroup C, was predicted to have a functional capsule. CONCLUSIONS:These data demonstrate the continued threat of N. meningitidis in military training populations and the need for whole genome sequencing in characterizing colonizing isolates and the determination of vaccination policies. Furthermore, these data support the current policy of quadrivalent vaccination in the military training population.

Abstract Background While the overall rates of Hepatitis C virus (HCV) in military populations are low, positive post-donation screening represents the second most common indication for post-donation infectious deferrals in military blood donors. All donors who screen positive are permanently deferred from blood donation, regardless of follow-up testing in clinical laboratories. There is limited data on the follow-up evaluation of these blood donors. This study describes the confirmatory testing, access to appropriate subspecialty care, and treatment of blood donors who screened positive for HCV at a large military blood bank. Methods All military blood donors between 2017-2023 at the Armed Service Blood Bank Center-San Antonio were screened for HCV by both antibody tests and nucleic acid tests, with positive antibody screening tests confirmed with an enzyme-linked immunosorbent assay (ELISA). Donors who screened positive had their medical charts reviewed to determine demographic information, follow-up evaluation, and treatment rates. On follow-up clinical diagnostic tests, patients with positive antibodies were determined to true positives (TP) and those with negative antibodies were determined to be FP. Results Of the 100,182 blood donors during the study period, 37 (0.04%) screened positive for HCV, of which follow-up information was available for 27 (73%). Of these 27, only 12 (44%) of donors were found to be TP. TP donors were more likely to be older (median 22 [20-29.5] vs. 20 [18-22], p=0.05) and have higher rates of positive nucleic acid testing (58% vs. 0%, p=0.001) after blood donation (Table 1). There was no difference in linkage to both primary and subspecialty care for TP and FP (Table 2). Of the TP, 7 (58%) were viremic, 3 (43%) of which received anti-viral therapy and 4 (57%) were administratively separated. Conclusion While HCV is one of the most common infectious reasons for military service members who donate blood to be deferred from future donations, most positive screenings were FP. Future efforts should be made to re-enter these patients with FP screening tests back into the donor pool. Disclosures All Authors: No reported disclosures

Microbiome analysis using metagenomics next-generation sequencing (mNGS) is rarely performed in patients receiving extracorporeal membrane oxygenation (ECMO). Patient body sites were swabbed within 72 hours of ECMO cannulation and weekly during ECMO course. Specimens underwent 16S sequencing to identify the microbiome along with mNGS to determine antimicrobial resistance genes. Fifty-two year old male who suffered polytraumatic injuries and developed acute respiratory syndrome was placed on veno-venous (VV) ECMO to treat severe respiratory failure. On ECMO day 1, the patient was undergoing treatment for urinary tract infection due to susceptible Pseudomonas aeruginosa (PsA). On ECMO day 22, the patient developed fulminant septic shock and tracheal aspirate and blood cultures both grew MDR PsA and Enterobacter cloacae complex (ECC) and ultimately died on day 23. There were significant microbiome and antimicrobial resistance changes that preceded sepsis on day 22, as evidenced by the increase in oral PsA colonization and expansion of resistance genes, such as KPC and OXA-50 , which suggest several possible reservoirs for infection outside of the circuit. Further application of these methods is needed to understand microbiome changes in ECMO and ultimately guide infection prevention efforts.

Viral and allergic conjunctivitis are more common than bacterial conjunctivitis in healthy immunocompetent adults. Neisseria meningitidis is an uncommon cause of bacterial conjunctivitis. During February-May 2025, an outbreak of 41 meningococcal conjunctivitis cases occurred among healthy, communally housed, military trainees at Joint Base San Antonio-Lackland in San Antonio, Texas; all had received the quadrivalent meningococcal vaccine. One patient was hospitalized with periorbital cellulitis and received intravenous antibiotics; all other patients were treated successfully with topical antibiotics. Whole genome sequencing of isolates from the first two cases suggested that the organism was unencapsulated (nongroupable) and that the cases were related. After the identification of two cases of N. meningitidis conjunctivitis among military trainees within a 3-week period in February 2025, an investigation was initiated by the base health surveillance team. Investigation of basic trainee hygiene and cleaning practices found that all protocols were followed; no source for the outbreak was found. When outbreaks of mucopurulent conjunctivitis occur in congregate living settings, culturing exudate can identify outbreak etiology, and whole genome sequencing can help guide treatment and response. Previous studies indicated that systemic antimicrobial therapy might be needed to prevent invasive infections of N. meningitidis cases; findings from this investigation suggest that nongroupable N. meningitidis conjunctivitis in otherwise healthy persons might be successfully treated with topical antimicrobials.

Objective:Despite concerns regarding toxicity and antimicrobial resistance, clindamycin prescriptions have remained significant at a large military healthcare system. This study evaluates patient and prescriber factors associated with outpatient clindamycin prescriptions. Design and setting:This study evaluated clindamycin prescriptions filled between January and December 2023 at outpatient pharmacies in a large military healthcare system. Patients:During the study period there were 1046 outpatients prescriptions for clindamycin among 972 adult and pediatric patients. Results:The cohort was predominately female (576, 55.1%) with a median age 48 [IQR 27.5-66]. The clinics with the most prescriptions were the emergency department (45.4%), primary care (23.6%), and surgical clinics (14.9%). While there were 533 prescribers, the ten highest writers of clindamycin accounted for 18.1% of all prescriptions. Beta-lactam allergy (38.5% vs. 16.0%, p ≤ 0.00001) was more common in patients with a dental indication and less common in those with a skin and soft tissue infection (51.3% vs. 23.3%, p ≤ 0.00001). Conclusions:Despite local guidelines, clindamycin was still frequently used for a variety of indications in a large military healthcare system with high clindamycin resistance rates. Additionally, a small number of providers were found to be responsible for a disproportionate number of clindamycin prescriptions, highlighting potential targets for intervention for future antimicrobial stewardship interventions.

BackgroundChlamydia trachomatis and Neisseria gonorrhoeae infections impose a significant burden to the military. In previous studies, women service members had higher rates of both these infections as compared to men for unclear reasons. This study evaluated if sex-based differences in infection rates for chlamydia and gonorrhea were due to sex-based differences in testing practices.MethodsA retrospective chart review was conducted on military service members who underwent testing for chlamydia and gonorrhea at Joint Base San Antonio between June 1, 2023 and September 31, 2023. The local electronic health record database was queried to determine patient demographics, clinical setting, indications for testing, and positivity rates.ResultsA total of 1620 (43%) patients were included for analysis. The cohort was predominantly women (67.5%) and enlisted (84.2%) with a median age of 27 years [IQR: 23-32]. Men were more likely to be tested for patient driven factors, such as symptoms (41.2%) or patient request (24.5%). Women were most frequently tested due to clinical algorithm (53.0%). Men were more likely to test positive for both chlamydia (8.7% vs 3.9%, p = <0.001) and gonorrhea (2.8% vs 0.4%, p = <0.001).ConclusionsAlthough women were more frequently tested for chlamydia and gonorrhea infections, men had significantly higher positivity rates, with more patient-driven indications for testing. The result of this study implies that sex-based testing practice differences in our study population might partially account for the higher rates in men. Importantly, it supports the need for future studies to evaluate the effectiveness of screening men in military settings.

Abstract Background Introduction: While clindamycin has broad Gram-positive and anaerobic activity, its use has been limited by toxicity and increasing resistance. Multiple clinical practice guidelines (CPGs) at Joint Base San Antonio recommend against clindamycin usage due to poor coverage of Gram-positive bacteria in local antibiograms. Despite this recommendation, a significant number of clindamycin outpatient prescriptions are ordered each year. The driver of these prescriptions is unknown. This study describes prescriber, diagnostic, and patient factors contributing to outpatient clindamycin usage at a large military medical system.Table 1Characteristics of 882 Patients Who Received an Outpatient Clindamycin Prescription at Joint Base San Antonio, 2023 Methods Outpatient clindamycin prescriptions from January-December 2023 filled at pharmacies on Joint Base San Antonio were evaluated to determine prescription duration, diagnostic indication, age, antibiotic allergies, prescriber, and prescribing clinic. Antibiotic indication was compared between those with beta-lactam allergies to those without beta-lactam allergies by Chi-squared.Table 2Prescriptions by Diagnostic Group and Beta-Lactam Allergy Status of Patient Results During the study period there were 941 prescriptions in 882 patients. The cohort was predominately female (52%) with a median age of 51 [IQR 40-68] (Table 1). Of these scripts, 229 (24%) were written by clinicians outside the military facility. The clinics with the most prescriptions were the Emergency Department (33%), Dental clinics (21%), Primary Care (16%), and Surgical clinics (14%). Patients with beta-lactam allergies were significantly more likely to have a dental indication (39.7% vs. 16.9%, p=< 0.0001) and those without beta-lactam allergies were more likely to have a skin and soft tissue infection (49.8% vs. 22.2%, p=< 0.0001) (Table 2). While there were 491 prescribers in this study, ten (2%) clinicians (six from the Emergency Department) prescribed 18% of all clindamycin prescriptions, 67% of which were in the absence of a beta-lactam allergy. Conclusion Patterns of outpatient clindamycin use across large health systems have not been well described. This study identifies potential areas for local stewardship interventions that have not previously been considered, including focused CPGs for emergency room clinicians as well as penicillin allergy de-labeling in outpatient dental clinics. Disclosures All Authors: No reported disclosures

BACKGROUND:Patients who test positive for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) should get retested to evaluate for reinfection. The US military has previously been reported to have high rates of CT and GC, but follow-up rates are unknown. This study evaluates factors associated with follow-up CT or GC testing in active-duty service members (ADSMs). METHODS:Positive cases of CT and GC among ADSM who were stationed at Joint Base San Antonio between January and June 2023 were evaluated in a retrospective chart review. A patient had follow-up testing if they had a repeat test within 3 to 12 months after their initial positive test result. Follow-up rates were compared among groups based on demographics, clinical setting of testing, and presence of symptoms. RESULTS:Of the 200 ADSMs who tested positive for CT or GC during the study period, 101 (51%) were men, and the median age was 23 (interquartile range, 20-26). One hundred forty (70%) were junior enlisted (E1-E4). Women received follow-up testing at a higher rate than men (71% vs. 51%; P = 0.003), without significant difference in follow-up testing by clinic, race, service, or organism. Women who were symptomatic at the time of initial test had a significantly higher rate of follow-up testing than did the symptomatic men (76% vs. 49%; P = 0.003). CONCLUSIONS:Despite standardized follow-up testing recommendations, there were significantly lower follow-up testing rates in men, with the greatest difference in testing in patients who were symptomatic at presentation. Future work should standardize follow-up testing of CT or GC infections in men.

Abstract Background Coagulase-negative Staphylococcus (CoNS) are frequently cited as the most common cause of bacteremia in patients receiving extracorporeal membrane oxygenation (ECMO). CoNS bacteremia is concerning in ECMO as the biofilm it forms can adhere to the circuit. Alternatively, CoNS can be colonizing or contaminants, and there are no standard definitions of CoNS bacteremia in ECMO. Additionally, appropriate workup and follow-up for CoNS bacteremia in ECMO patients is unknown. This study evaluates the etiology and workup of CoNS in a cohort of patients receiving ECMO at a military medical center. Characteristics of the 13 patients receiving ECMO with Coagulase-negative Staphylococcus isolated from blood cultures Methods All patients who received ECMO between January 2022 and March 2024 were included in this retrospective study. All blood cultures were reviewed and patients with a positive blood culture for CoNS were included for further analysis including patient demographics, indication for culture, follow-up of culture results, treatment, and patient outcomes. Characteristics of CoNS with Repeated Blood Culture Positivity as Compared to Single Blood Culture Positivity in Patients Receiving ECMO. Results Of the 68 patients who received ECMO during the study period, there were 424 blood culture sets obtained, of which 20 (4%) yielded CoNS in 13 (19%) patients. Patients were predominantly male (85%) with a median age of 35 [IQR: 26-50] (Table 1). The most common indication for culture in this cohort was fever (62%) and most cultures were drawn from peripheral draws. All CoNS were monomicrobial and S. epidermidis (85%) accounted for the majority of cases. Only 5 (38%) patients had repeat growth of CoNS on repeat cultures, yet 8 (62%) were treated with antimicrobials (Table 2). Two (15%) patients, both with persistent culture positivity, were found to have infective endocarditis. Of patients with multiple isolations of CoNS, all survived to hospital discharge. No patient had reisolation of CoNS after treatment. Conclusion CoNS was frequently isolated in blood cultures from patients receiving ECMO. Despite the concern for biofilm formation, most CoNS was only isolated in one culture, and bacteremia was not associated with increased mortality, even when isolated repeatedly. Based on this data, it is reasonable to recommend treatment of CoNS bacteremia, only when isolated on repeat cultures. Standardization of CoNS bacteremia reporting, in addition to treatment in ECMO is needed. Disclosures All Authors: No reported disclosures