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Ilges, Dan

0000-0003-0778-3901

Mayo Clinic

Department of Pharmacy, Mayo Clinic Arizona, Pheonix, AZ, USA.

Citations 23

Risk Factors Associated with Positive Intraoperative Valve Tissue Cultures and the Subsequent Impact on Infective Endocarditis Management and Outcomes
Bhattarai, Nirjan , Stevens, Ryan W. , Baddour, Larry M. , DeSimone, Daniel C. , Chesdachai, Supavit , Hindy, Joya-Rita , Dierkhising, Ross , Ilges, Dan , Baddour, Larry , DeSimone, Daniel C , Stevens, Ryan W , Ilges, Dan

Open Forum Infectious Diseases | September 17, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1093/ofid/ofag568 Get It

Abstract Background Cardiac valve tissue obtained during the surgical management of infective endocarditis (IE) and sent for culture may influence postoperative antibiotic therapy. We sought to identify clinical and microbiologic risk factors associated with positive valve cultures (PVC) and IE relapses in a cohort of patients undergoing surgical management. Methods This is a retrospective, multi-center study of patients with surgical management during the acute (<42 days) course of IE-directed antibiotic therapy. The rate of PVC, IE relapse, and mortality were collected. Univariate and multivariable logistic regressions were performed to identify risk factors associated with PVC. Results Of 113 patients included, 36 (31.9%) had PVC. Univariate and multivariable analyses showed preoperative antibiotic duration and pathogens were associated with PVC. Median (IQR) days of preoperative antibiotics were 6.5 (4.0-11.0) for patients with PVC compared to 13.0 (8.0-21.0) for those with negative valve cultures (NVC). In a multivariable model, preoperative antibiotic administration decreased the risk of PVC (OR 0.85 per day, CI 0.77-0.91). Enterococcal IE increased the risk of PVC compared to streptococcal IE (OR 4.16, CI 1.07-17.48). Of note, 33 (63.2%) patients with NVC received a median (IQR) of 8 (5, 18.5) days of intravenous antibiotics per patient. Only one IE relapse was identified and occurred in a patient with NVC. Conclusions Both preoperative antibiotic duration and causative pathogen were associated with PVC. IE relapses were rare and unrelated to PVC. There may be an opportunity to shorten postoperative antibiotic durations following surgical management in patients with IE.
Settling the score: the past, present, and future of antimicrobial spectrum scoring
Ilges, Dan , Stevens, Ryan W. , Stevens, Ryan W , Ilges, Dan

Clinical Infectious Diseases | July 31, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1093/cid/ciag471 Get It

Anticalcitonin: limited utility of a context-dependent biomarker demonstrated in another real-world data set
Ilges, Dan , Shah, Aditya , Stevens, Ryan W. , McCreary, Erin K, Stevens, Ryan W , Ilges, Dan , McCreary, Erin K

Clinical Infectious Diseases | June 30, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1093/cid/ciag396 Get It

Ambulatory antibiotic prescribing for acute sinusitis: a multicenter, retrospective cohort study evaluating appropriateness
Hannan, Kellie N. Arensman , Ilges, Dan , Le, Kimberly T. , Mara, Kristin C. , Stevens, Ryan W., Jensen, Kelsey , Arensman Hannan, Kellie , Mara, Kristin C , Jensen, Kelsey , Ilges, Dan , Le, Kimberly Thi , Stevens, Ryan W.

Antimicrobial Stewardship & Healthcare Epidemiology | June 25, 2026 | Volume: 6 | Issue: 1 | Pages: No page available

10.1017/ash.2026.10743 Get It

Abstract Objective: Antibiotics are frequently prescribed for acute sinusitis despite national guidelines recommending antibiotics only if specific symptom criteria are met. We aimed to define the proportion of acute sinusitis encounters meeting criteria for antibiotic prescribing, characterize prescribing practices, and identify factors associated with guideline-discordant prescribing. Design: This retrospective cohort study included 1,000 randomly selected adult ambulatory encounters with a primary diagnosis of acute sinusitis between January 1, 2024 and March 31, 2024. Encounter notes were reviewed for appropriate antibiotic prescribing criteria as per national guidelines. Encounters were evaluated for drug selection and duration concordance based on local guidelines. A multivariable logistic regression analysis was performed to identify predictors of inappropriate antibiotic prescribing. Setting: Emergency departments, urgent care centers, and primary care clinics. Results: Antibiotic prescribing criteria were met for 67.6% of included encounters. Antibiotics were prescribed in 93.5% of encounters that met prescribing criteria, and 80.2% of encounters that did not. Both drug selection and duration were guideline-concordant in 49.2% of total encounters. On multivariable analysis, predictors of inappropriate antibiotic prescribing included cough (OR 2.15, 95% CI 1.08–4.29; P = 0.03) and symptom duration between 7 and 9 days (compared to <6 days; OR 7.70, 95% CI 3.24–18.31; P < 0.001). Electronic encounters were associated with lower odds of prescribing compared to in-person encounters (OR 0.03, 95% CI 0.01–0.09; P < 0.001). Conclusions: Most encounters for acute sinusitis result in an antibiotic prescription, despite prescribing criteria not being met. These findings may aid antimicrobial stewardship programs in benchmarking and optimizing antibiotic prescribing for acute sinusitis.
Crushed posaconazole delayed-release tablets via enteric feeding tube administration: practical considerations for clinicians
Bhattarai, Nirjan , Ilges, Dan , Stevens, Ryan W. , Stevens, Ryan W , Ilges, Dan

Journal of Antimicrobial Chemotherapy | May 28, 2026 | Volume: 81 | Issue: 7 | Pages: No page available

10.1093/jac/dkag201 Get It

Abstract Posaconazole delayed-release (DR) tablets are labelled as ‘do not crush’ medications. Despite this designation, emerging research demonstrates successful attainment of therapeutic serum concentrations, suggesting that they may be pharmacokinetically superior to the immediate-release (IR) suspension when given via enteric feeding tube (EFT). While crushed posaconazole DR tablets may be better suited than the IR suspension to attain therapeutic serum concentrations, several practical factors must be considered, including lack of dose equivalency between crushed DR tablets for EFT administration and DR tablets swallowed whole and the risk of EFT occlusion. This article summarizes the current evidence on posaconazole serum concentrations with crushed DR tablets administered via EFT, explores risks of this practice and provides mitigation strategies for application in the clinical setting, including proposed dosing and administration practices.
Point-Counterpoint: Should MRSA nares testing be used as a tool for vancomycin de-escalation outside of pneumonia?
Ilges, Dan , Dickinson, Drew T. , Bosquez, Jennifer M., Graf, Erin H. , Graf, Erin H , Ilges, Dan , Bosquez, Jennifer M.

Journal of Clinical Microbiology | April 21, 2026 | Volume: 64 | Issue: 5 | Pages: No page available

10.1128/jcm.01309-25 Get It

ABSTRACT Vancomycin is broadly used to treat gram-positive infections in both inpatient and outpatient settings. Its use is primarily for the treatment of methicillin-resistant Staphylococcus aureus (MRSA), which is a common cause of pneumonia, skin and soft tissue infections, and bloodstream infections. Vancomycin therapy requires close clinical monitoring to maintain therapeutic efficacy and, importantly, patient safety. Vancomycin use is associated with acute kidney injury in up to 20% of cases, a number that can be driven down by pharmacokinetic dosing protocols. However, the best mitigation against adverse outcomes associated with vancomycin is to ensure it is only used when needed and rapidly de-escalated when not. As such, many stewardship programs, who are tasked with the safe and effective use of antimicrobial agents, have focused on optimizing vancomycin use. There is a strong correlation with MRSA colonization and infection, and a negative MRSA nares screen has a good negative predictive value for MRSA pneumonia (although this association is less well documented for other infections). As such, detection of MRSA in nares swabs, by nucleic acid amplification tests (NAATs) or culture, is a logical tool for stewarding vancomycin. However, the application of MRSA screening tests as MRSA diagnostics is complex, as these tests are cleared by the U.S. Food and Drug Administration for the detection of MRSA colonization, and not for therapeutic decision making. In this issue of the Journal of Clinical Microbiology, the issue of MRSA nares tests is debated by a clinical pharmacy team and the laboratory. The authors review the clinical evidence and regulatory background in which an MRSA nares NAAT may be used to inform treatment decisions.
Fosmanogepix Treatment for Coccidioidomycosis Under an Expanded Access Program
Cohen, Stuart H. , Allyn, Paul , Rathe, Jennifer , Nanayakkara, Deepa , Hutfles, Gerald, Vijayan, Tara , Smith, Ethan A , Saling, Christopher , Ilges, Dan , Schlamm, Haran T., Thompson, George R. , Rathe, Jennifer , Hutfles, Gerald , Vijayan, Tara , Smith, Ethan A , Ilges, Dan , Thompson, George R , Allyn, Paul R , Chow, Felicia C.

Clinical Infectious Diseases | April 18, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1093/cid/ciag271 Get It

Abstract Coccidioidomycosis is an invasive fungal infection that can disseminate and cause severe disease. Fosmanogepix (“gepix”), a first-in-class antifungal available via expanded access (NCT06433128), was successful in 8/11 patients (meningitis, 6/8 [75%]; nonmeningeal dissemination, 2/3 [66%]) and was well tolerated for a median treatment duration of 208 days.
Impact of positive donor blood cultures on solid organ transplant recipient outcomes
Ford, Edith , Votruba, Cassandra , Saling, Christopher , Vikram, Holenarasipur R. , Ilges, Dan , Vikram, Holenarasipur R. , Ilges, Dan

Infection Control & Hospital Epidemiology | April 10, 2026 | Volume: 47 | Issue: 6 | Pages: 547-552

10.1017/ice.2026.10454 Get It

Abstract Objective: To define the incidence of donor-derived infection (DDI) in recipients of solid organ transplant (SOT) from donors with positive blood cultures and to assess the impact of shorter versus longer duration of targeted preemptive antibiotic therapy (PAT). Design: Retrospective, single-center, cohort study. Setting: Mayo Clinic Arizona. Patients: Recipients transplanted between 1/1/2019 and 7/1/2024 who received an organ from a donor with positive blood cultures. Methods: The primary outcome was incidence of DDI. Secondary outcomes included duration of PAT and incidence of donor blood culture contamination. Results: Among 199 SOT recipients from 167 unique donors with positive blood cultures, two recipients developed confirmed DDI within 30 days of SOT. Both cases were gram negative bacillary bacteremia not treated in donors and occurred immediately posttransplant prior to adequate recipient PAT. Six-month graft survival and recipient survival were 96.5% and 97.5% respectively. 139 recipients (69.8%) received PAT for a median duration of 7 days. There was no difference in rate of infections between recipients provided with ≤7 days versus 8–14 days of PAT for donor blood cultures; however, recipients who received 8–14 days had more Clostridioides difficile infections (CDIs) within 60 days of SOT (7.7% vs 1.5% ≤ 7 days, P = .040) and were more often discharged on intravenous antibiotics (32.3% vs 11.3%, P < .001). Conclusion: We observed a low rate of DDI following receipt of organs from donors with positive blood cultures. DDI occurred in cases without adequate donor/recipient treatment. Longer durations of targeted PAT resulted in more CDI and intravenous antibiotics on discharge.
Trends in Long-Duration Antibiotic Prescribing Following Focused Outpatient Antimicrobial Stewardship Efforts Across a Large Healthcare Enterprise
Ilges, Dan , Jensen, Kelsey , Draper, Evan , Thompson, E., Quillen, Jaxon , Hannan, Kellie Arensman, Ton, Angie , Prigge, Kimberly , Vergidis, Paschalis , Virk, Abinash, Hannan, Kellie N. Arensman , Arensman Hannan, Kellie , Ton, Angie Nu , Prigge, Kimberly A , Virk, Abinash , Stevens, Ryan W , Vergidis, Paschalis , Jensen, Kelsey , Ilges, Dan , Quillen, Jaxon K , Virk, Abinash , Stevens, Ryan W.

Clinical Infectious Diseases | April 8, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1093/cid/ciag244 Get It

Abstract Background Outpatient antibiotic stewardship programs (ASP) are recommended by the CDC and Joint Commission. We analyzed the impact of annual, focused syndrome-specific ASP interventions on trends in long-duration antibiotic prescribing (LDAP). Methods This was a retrospective, observational, multicenter cohort study from November 2020 through June 2025. All ambulatory encounters generating systemic antibiotic prescriptions within the healthcare enterprise were screened. Hospitalizations, emergency department visits, and infectious diseases encounters were excluded. Encounters generating ≥1 systemic antibiotic with &gt;7 days duration were categorized as long-duration. Targeted departments (primary and urgent care) received direct intervention (eg, education, peer-comparison reporting, data tracking). LDAP was modeled over time by month and compared by diagnosis group (ASP-priority diagnoses vs nonpriority) and provider specialty department (ASP-targeted vs nontargeted) using linear regression models. Results Of 642 579 encounters included, 42.2% were long duration. LDAP in ASP-targeted departments dropped from 46.8% to 34.8% (difference −12 percentage points [pp]), whereas nontargeted departments dropped from 45.5% to 39.1% (difference −6.4 pp). The estimated annual LDAP decrease was 3.4 pp in targeted versus 2.4 pp in nontargeted departments (difference 1.0 pp, P = .009). Within targeted departments, significant LDAP decreases were seen both in priority and nonpriority diagnoses, whereas nontargeted departments showed no change in LDAP in priority diagnoses. In a sensitivity analysis of nonpriority diagnoses, ASP-targeted departments had a larger estimated annual decrease in LDAP versus nontargeted (difference 1.4 pp, P &lt; .001). Conclusions Annual syndrome-specific ASP interventions correlated with improvements in LDAP, including outside of priority syndromes in targeted departments. LDAP is a viable metric for evaluating ambulatory ASPs.
Outpatient penicillin allergy de-labeling in primary care—whom to target
Ton, Angie , Ilges, Dan , Ilges, Dan

Antimicrobial Stewardship & Healthcare Epidemiology | March 27, 2026 | Volume: 6 | Issue: 1 | Pages: No page available

10.1017/ash.2026.10331 Get It

Abstract Education and allergy referral via nurse-driven online messaging to patients (n = 1,284) with penicillin allergy labels (PALs) reduced PALs by 8.6%. The percentage decrease of “unknown” (14.8%) and “rash” (7.9%) PALs were higher vs “hives” (6.1%) and “itching” (1.4%) reaction types.