Igwilo-Alaneme, Rita

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.

Abstract Background The number of arthroplasty procedures and infection-related complications, including prosthetic joint infections (PJIs) and surgical site infections (SSIs), continues to rise. Although current guidelines recommend cefazolin or cefuroxime as the first-line perioperative prophylactic antibiotic, substitutions with non-cephalosporins remain common, especially among patients with reported β-lactam allergies. These substitutions may increase infection risk and healthcare costs. Evidence comparing outcomes across antibiotic classes remains variable. Methods We conducted a systematic review and meta-analysis of studies comparing single-agent cephalosporin versus single-agent non-cephalosporin prophylaxis in adults undergoing primary arthroplasty. Cochrane, Embase, Medline, Scopus, and Web of Science were searched from database inception through January 2025. Random-effect or fixed-effect models were used to estimate pooled odds ratios (OR) and 95% confidence intervals (CI). Subgroup analyses stratified results by cephalosporin type, study era, and risk of bias. Results Twenty-three studies (7 randomized controlled trials and 16 observational studies) were included, encompassing 191 527 arthroplasties in the cephalosporin arm and 20 058 in the non-cephalosporin arm. The odds of PJI were lower with cephalosporins (OR 0.59; 95% CI, .46–.75). No overall difference was observed for SSI (OR 0.70; 95% CI, .36–1.36), though post-2013 studies and the cefazolin subgroup demonstrated a significant protective effect. Randomized trial estimates were limited and heterogeneous and did not reach statistical significance. Certainty of evidence was graded as moderate. Conclusions Cephalosporins, particularly cefazolin or cefuroxime, remain the preferred prophylactic agents for primary arthroplasty. This quantitative synthesis reinforces their protective association against prosthetic joint infection and supports adherence to guideline-endorsed prophylaxis.

Abstract Background Native vertebral osteomyelitis (NVO) is a life-threatening spinal infection with rising incidence and significant morbidity. Despite its growing burden, long-term data on clinical characteristics, management trends, and outcomes remain limited. Methods We conducted a 26-year multicenter retrospective cohort study of adults (≥18 years) diagnosed with NVO at Mayo Clinic sites between 1999 and 2024. Demographic, microbiologic, treatment, and outcome data were analyzed across five time periods. Predictors of treatment failure were assessed using a multivariable competing risk model. Results Among 1255 patients (median age 67; 66% male), lumbosacral involvement was most common (65%), and 21% had multilevel involvement. Pathogens were identified in 77%, most commonly Staphylococcus aureus (49%; Methicillin-susceptible S. aureus 37%, methicillin-resistant S. aureus 13%). Over time from 1999–2004 to 2020–2024, Gram-negative bacilli increased from 6% to 14% (P = .048). Comorbidities including chronic kidney disease (10% to 21%), active chemotherapy (6% to 11%), and immunosuppression (8% to 17%) increased significantly. Additionally, 1-year treatment failure declined (16% to 10%). In multivariable analysis, diabetes mellitus (subdistribution hazard ratio [sHR] 1.92, 95% CI 1.18–3.13) and multilevel involvement (sHR 1.67, 95% CI 1.17–2.38) were associated with increased incidence of treatment failure, while concurrent infections (sHR 0.57, 95% CI 0.37–0.87) and higher Charlson Comorbidity Index (sHR 0.62, 95% CI 0.43–0.90) were associated with lower failure. Conclusions This large multicenter cohort highlights increasing host complexity, shifting microbiology, and predictors of failure, emphasizing the importance of early risk stratification and tailored strategies, such as multidisciplinary evaluation and close follow-up of high-risk patients to improve outcomes.

Abstract Background In 2019, the US performed 290,000 breast reconstructions with an estimated infection rate of 3-35%. Tissue expander infections detract from desired aesthetic effects, delay adjuvant treatments, increase morbidity and mortality, and have high recurrence rates (20-40%). Little is known about risk factors for recurrent tissue expander infections, particularly the impacts of different treatment modalities. Methods We conducted a single-center retrospective cohort study of adult women post-mastectomy who developed microbiologically-proven tissue expander infection between the period of 2017 – 2024. Outcomes including 12-month infection recurrence and risk factors for recurrence were compared between surgical versus nonoperative groups, as well as between three surgical strategies (i.e., one-stage, two-stage, explantation). Unadjusted and adjusted logistic regression models were used to assess the associations between the treatment modalities and the outcomes. Univariate models assessed the relationship between the covariates of interest and infection recurrence. Results 107 patients were included, with the majority treated with combination of antibiotics and surgical therapy (Table 1). There was no significant difference in outcomes when the operative versus antibiotics alone cohorts were compared (Table 2). The odds of infection recurrence and rehospitalization in patients who underwent two-staged exchange or explantation were significantly lower when compared with the one-staged group (Table 3). Univariate modeling found severity and radiation therapy to be numerically more common in the group experiencing recurrence, with a trend towards statistical significance (Table 4). Conclusion Our study demonstrates reduced risk of recurrent tissue expander infection with two-staged exchange or explantation, compared to one-staged exchange. Though limited by small sample size, the strengths of our study include our presentation of the real-world variability of these syndromes and their management, adjustment for infection severity and other potential confounders; and the focus on microbiologically-defined infections. Disclosures All Authors: No reported disclosures

Abstract Background Native vertebral osteomyelitis (NVO) is a life-threatening spinal infection with considerable clinical burden. Although increasing literature has described its features and associated treatment failure, large-scale cohorts with long-term follow-up remain limited. Herein, we evaluated a large cohort of patients with NVO to characterize the clinical manifestations, management, and long-term outcomes, and to further explore factors associated with treatment failure.Table 1.Baseline characteristics of patients with native vertebral osteomyelitisTable 2.Treatment, failure rates, and mortality in patients with native vertebral osteomyelitis Methods We conducted a retrospective multicenter cohort study of adults (≥18 years) with NVO across Mayo Clinic sites between 1999 and 2024. Data on demographics, clinical manifestations, antimicrobial therapy, and surgical intervention were collected. Cumulative incidence of treatment failure was estimated as a function of follow-up accounting for the competing risk of death. Independent predictors of treatment failure were evaluated in a multivariable Cox regression model with time-dependent covariates.Table 3.Multivariable predictors of treatment failure in patients with native vertebral osteomyelitisFigure 1.Cumulative incidence of death and treatment failure following diagnosis of native vertebral osteomyelitis(A) Short-term (12-month) cumulative incidence of death and treatment failure (magnified view of the first year from panel B).(B) Long-term (up to 7 years) cumulative incidence of death (dotted orange line) and treatment failure (solid blue line). Results Among 1,255 patients included (median age 67 years; 66% male), lumbosacral involvement was most common (65%), with multilevel vertebral involvement ( &gt;2 levels) in 21%. Epidural abscesses were present in 43%, paravertebral abscesses in 42%, and psoas abscesses in 20%. Pathogens were identified in 77%, most commonly S. aureus (50%; MSSA 37%, MRSA 13%), followed by Streptococcus species (22%), and Gram-negative bacilli (11%) (Table 1). The median total antibiotic duration was 59 days (IQR, 42–132). Surgical intervention was performed in 13% after a median of 2 days (IQR, 1-5). Treatment failure occurred in 162 patients during a median follow-up of 2.8 years (6-month and 5-year cumulative incidence were 11% and 14%, respectively), with the median time to failure of 3.1 months. Cumulative mortality was 12% at 6 months and 33% at 5 years (Table 2, Figure 1). Diabetes (HR 1.90, 95% CI 1.16–3.12), multilevel vertebral involvement (HR 1.75, 95% CI 1.22–2.51), and MRSA infection (HR 2.11, 95% CI 1.06–4.18) were independently associated with increased risk of treatment failure (Table 3). Conclusion This 25-year study highlights the persistent burden of treatment failure in NVO and associated risk factors, underscoring the importance of early recognition of high-risk features to optimize outcomes. Disclosures All Authors: No reported disclosures

Abstract Background Despite advancements in vaccination, mortality from Pneumococcal blood stream infections remains high (∼20%). Risk factors include host comorbidities (e.g., immunosuppression, kidney disease, alcohol use, smoking) and certain serotypes. While intensive care unit (ICU) admission and septic shock are associated with poor outcomes, predictors of severe disease remain underexplored. Characteristics of patients with ICU admission within 24 hours of invasive pneumococcal disease diagnosis Epidemiology, clinical characteristics, metastatic complications and management of invasive pneumococcal disease (IPD) Methods We conducted a retrospective review of hospitalized adults with Streptococcus pneumoniae bacteremia between 2013-2023. Clinical comorbidities, laboratory values, vaccination status, microbiologic data, and treatment strategies were collected. Descriptive statistics and univariate logistic regression were used to assess predictors of ICU admission using R Studio v4.4.3 Univariate logistic regression analysis for predictors of ICU admission within 24 hours of diagnosis of streptococcus pneumoniae blood stream infection Rates of streptococcus pneumoniae blood cultures over the years- seasonality trends Results A total of 185 patients were included; the majority were male (60%) with a median age of 64 years (Table 1). Immunocompromising conditions were present in 60%, and only 43% were up to date with pneumococcal vaccination. Metastatic infection was identified in 28% of cases, most commonly meningoencephalitis (74%), musculoskeletal involvement (28%), and endocarditis (12%). ICU admission within 24 hours of presentation was required in 55% of patients (Tables 2 and 3). Predictors of ICU admission included active smoking (OR 2.20), substance use within the past five years (OR 3.45), presence of metastatic foci (OR 2.39), and neurologic complications (OR 6.10). Up-to-date pneumococcal vaccination demonstrated a trend toward a protective effect. 30-day and 90-day mortality rates were 18.9% and 25.4%, respectively. Other predictors of 30-day mortality included smoking history, higher Charlson comorbidity index (CCI), hemodynamic shock at admission, and lab abnormalities such as hypoalbuminemia and elevated liver enzymes. Among the 69 isolates with available serotype data, serogroups 22 and 15 were most frequently identified. Conclusion Pneumococcal bloodstream infections are associated with substantial mortality, particularly among patients requiring ICU admission. Smoking, recent substance use, and the presence of metastatic complications were significantly associated with severe disease and ICU admission. Up-to-date pneumococcal vaccination demonstrated a protective effect. Disclosures All Authors: No reported disclosures

Abstract Background Streptococcus agalactiae (group B Streptococcus [GBS]) may cause pneumonia or may colonize the respiratory tract, making its clinical significance uncertain when detected in respiratory specimens. This study aimed to assess whether clinicians interpreted GBS detected by the BIOFIRE Pneumonia Panel (BF-PP) as a pathogen implicated in pneumonia. Methods This retrospective cohort study included adult patients hospitalized with suspected pneumonia at Mayo Clinic, Rochester, between September 2020 and February 2025. Cases were independently classified into pathogen and nonpathogen groups by 2 infectious diseases (ID) specialists, with a third reviewer resolving disagreements. Clinical characteristics and outcomes of both groups were recorded. A subgroup analysis of patients who had an ID consultation was performed. Results A total of 109 cases were included. GBS was considered a pneumonia pathogen in 47.7% of cases and a nonpathogen in 52.3%. ID consultation was performed in 33.0% of cases, with GBS considered a pathogen in 30.6% of those. Common comorbid conditions included pulmonary, gastrointestinal, neurologic, and cardiovascular disease and obesity. Rates of endotracheal intubation were similar in the pathogen and nonpathogen groups (51.9% vs 50.9%, respectively), with the in-hospital mortality rate being numerically but not significantly higher in the former versus the latter (21.2% vs 14.0%; P = .33); findings were similar in the ID-assessed subgroup. In 76.1% of GBS detections, other microorganisms—most commonly Staphylococcus aureus—were codetected. Only 10.2% of BF-PP GBS-positive specimens were culture positive for GBS. Conclusions While GBS is not an uncommon pneumonia pathogen, the clinical significance of its detection by BF-PP is uncertain in many cases.

Aims Native vertebral osteomyelitis (NVO) and infective endocarditis (IE) are increasingly seen as interconnected conditions, sharing similar risk factors — such as advanced age and immunosuppression — and overlapping microbial profiles, notably Staphylococcus aureus and streptococci. When these infections occur together, they present distinct challenges in diagnosis and treatment, which can obscure clear outcomes and mortality estimates. Therefore, we aimed to systematically assess the combined mortality associated with concurrent NVO and IE and to detail the clinical characteristics of affected patients. Methods We conducted a systematic review following the PRISMA framework, searching MEDLINE, Embase, the Cochrane Library, and Scopus for relevant studies published between 1970 and October 2023. Studies included were those reporting mortality outcomes for at least ten adult patients with both NVO and IE. Two independent reviewers screened the literature, extracted data, and evaluated study quality using a modified Newcastle-Ottawa Scale. We then performed a random-effects meta-analysis to pool in-hospital, 1-month, 1-year, and 3-year mortality rates. Results A total of 16 studies (12 retrospective, 3 prospective, and 1 mixed design) involving 641 patients (mean age 67.1 years) with concomitant NVO and IE were included. The pooled in-hospital mortality rate was 10.0% (95% CI: 5.2–14.7%), with mortality rates of 5.6% (95% CI: 2.2–9.0%) at 1 month, 12.1% (95% CI: 5.3–18.8%) at 1 year, and 14.5% (95% CI: 4.3–24.8%) at 3 years. There was significant heterogeneity among studies (I² ranging from 46% to 86%). Common comorbidities included diabetes (24.6%), renal failure (17.3%), and immunosuppression (11.1%). The predominant pathogens identified were streptococci (31.3%), S. aureus (27.3%), and enterococci (13.7%). Approximately 40.6% of patients underwent surgical intervention, though its effect on mortality remains inconclusive. Overall, the certainty of the estimates was limited by imprecision and impossibility of perform subgroup analysis. Conclusion The coexistence of NVO and IE is associated with significant mortality, emphasizing the need for earlier diagnosis, coordinated multidisciplinary management, and standardized treatment protocols. Future prospective, high-quality studies are crucial to determine optimal diagnostic and surgical strategies for managing this complex clinical scenario.

Abstract Background The introduction of shotgun metagenomic sequencing (sMGS) methods that identify the presence of microbial cell-free DNA (mcfDNA) in peripheral blood have shown promising results in various populations of patients. There is a pressing need to evaluate its application for osteoarticular infections (OAIs) in real-world setting. Baseline characteristics of the patients with suspected osteo-articular infections, including demographics, clinical characteristics, diagnosis, and KT results. Methods We retrospectively collected data on 73 adult patients who presented to the Mayo Clinic with suspected OAIs between 2019 and 2023, and for whom mcfDNA sMGS (Karius®, KT) testing was part of their diagnostic workup. We collected data on comorbidities, diagnostics, microbiological workout and its concordance with the KT. The primary objective was to evaluate its clinical impact on OAI diagnoses and management distinguishing into four categories: (1) KT was able to confirm an established diagnosis, (2) KT supported non-ID diagnosis, (3) KT established an unsuspected diagnosis, (4) KT did not add relevant information. Relevant microbiologic studies of patients with unsuspected diagnoses established by the KT (N=5) Results In our cohort KT was performed in 73 patients (Table 1). Among the infected individuals, KT yielded positive results in 22/43 (51.2%) cases. Out of these 22 cases, 11 (50%) showed agreement with conventional diagnostic workup, while in five (22.7%) cases, the KT established an unsuspected diagnosis, improving the diagnostic power from 11/43 (25.6%) to 16/43 (37.2%) (Table 2). Moreover, yielded a negative result in 19/26 (73.1%) patients with non-infectious diagnosis (Figure 1). Native Vertebral Osteomyelitis (NVO) diagnosis (p &lt; 0.001) or OAIs with concomitant presence of endocarditis or endovascular infection (p = 0.005) were statistically associated with a definite, probable, or possible diagnostic certainty of KT result (Table 3). Overall, KT influenced antibiotic therapy in six cases (8.2%). Table 3 Factors associated with diagnostic certainty categories Conclusion This is the first retrospective study aiming to assess the real-world usefulness of the KT on the clinical management of patients with OAIs, with a special focus on NVO. It underscores KT's real-world application in cases where traditional diagnostic methods fall short. In highly complex OAIs cases, KT added 11.6% to the diagnostic power by establishing unsuspected diagnosis in 5 of 43 infective patients. Patients with NVO or OAIs with concomitant endocarditis or endovascular infections particularly benefited from KT testing. Figure 1 Distribution of KT results and their respective outcome according to the final diagnosis of suspected OAIs cases. Disclosures All Authors: No reported disclosures

Abstract Background Culture-negative native vertebral osteomyelitis (CN-NVO) is increasingly common, rising from 0.3 to 1.8 cases per 100,000 between 1995 and 2008. The lack of microbial identification complicates optimal treatment and creates prognostic uncertainties. We describe our decade-long clinical experience with CN-NVO, focusing on patient characteristics, treatment, and outcomes. Patient Characteristics Methods We retrospectively analyzed adult patients with radiographic evidence of NVO between January 1, 2011, and July 31, 2021. CN-NVO required clinical indicators such as back pain and fever, elevated inflammatory markers, and negative cultures from at least one spine biopsy. Patients with infected instrumentation were excluded. Diagnostic Evaluation Values represent median, lower quartile, and upper quartile for continuous variables unless otherwise specified, 2 whereas frequencies and percentages are presented for categorical variables. ^ All results returned negative *Biopsies number two and three did not result in additional findings or change clinical management. Results Seventy-two patients were included. Their characteristics are presented in Table 1. Most (77.8%) had received antibiotics within the 4 weeks preceding the biopsy. Disc space enhancement on MRI was the primary finding, with the lumbar spine being the most frequently involved (Table 2). Blood cultures were positive in 39.4% of the patients within 3 months of symptom onset. Streptococcus spp. (n=9, median time between positive culture and diagnosis: 6.5 days [IQR 2.25, 26.75]) and Staphylococcus aureus (n=7, 40 days [IQR 37.5, 51.5]) were most common. Definitive antibiotics were administered in 98.6% of the cases, primarily IV β-lactam + vancomycin. Oral antibiotics (PO) were used in 46.5% of the patients, primarily as step-down therapy (91%) (Table 3). Surgery was required in 8.5% of the patients for abscess drainage or relief of spinal cord compression. Treatment failure occurred in 9.4% of patients, and 37.5% died during the median follow-up of 568.5 days, with two deaths related to the infection. Treatment and Outcomes ^ defined as requiring another course of antibiotics and/or surgery for suspected ongoing infection ¶ Clinical findings include back pain or fevers; laboratory findings indicate abnormal or uptrend in inflammatory marker values # Defined as MRI findings concerning ongoing or worsening infection as per the interpretation of the Radiologist, Infectious Disease physician, and/or Orthopedic Surgeon Conclusion Patients with CN-NVO often require prolonged antibiotic therapy, typically combination regimens, with favorable treatment outcomes. Our treatment failure rate is similar to other studies, although comparability may be limited by heterogeneity in definitions. Mortality rates in the range of 6 and 36% have been reported, with the higher end driven mostly by comorbidities. Enhanced diagnostics and standardized treatment protocols are needed to further improve patient outcomes. Disclosures All Authors: No reported disclosures