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O’Horo, John C.

https://orcid.org/0000-0002-0880-4498

Mayo Clinic

Mayo Clinic

Citations 126

Azithromycin versus doxycycline in hospitalised adult patients with community-acquired pneumonia treated with beta-lactams: protocol for a pragmatic randomised clinical trial
Tekin, Aysun , Lal, Amos , Brogan, Autumn , Bellolio, Fernanda , O’Horo, John C. , Yadav, Hemang , Schulte, Phillip, Gajic, Ognjen, Barreto, E, Odeyemi, Yewande , Odeyemi, Yewande E , Lal, Amos , Bellolio, M Fernanda , O'Horo, John C , Tekin, Aysun , Gajic, Ognjen , Frazee, Erin N.

BMJ Open | July 27, 2026 | Volume: 16 | Issue: 7 | Pages: e118028

10.1136/bmjopen-2026-118028 Get It

Introduction Community-acquired pneumonia (CAP) is common and remains the leading infectious cause of death worldwide. Antibiotics remain the mainstay of treatment, but organisms are often not identified, necessitating empirical treatment. Current treatment guidelines recommend combination therapy with beta-lactams and macrolides or monotherapy with fluoroquinolones for non-severe CAP. However, rising antibiotic resistance and safety concerns have led to increased doxycycline use, despite limited evidence supporting its efficacy. Our goal is to conduct a pragmatic, open-label, randomised clinical trial comparing the effectiveness of azithromycin with that of doxycycline in combination with beta-lactam therapy in adult patients hospitalised for CAP. Methods and analysis Patients presenting to the emergency department or directly referred to the hospital with a clinical presentation concerning for CAP and need for hospitalisation are eligible. We plan to enrol 1120 adults hospitalised at six hospitals across four states, including rural, suburban and urban settings and academic and community hospitals. Randomisation will be 1:1 using an electronic health record (EHR)-embedded screening and randomisation tool triggered by the treating clinician’s orders for azithromycin or doxycycline. Outcomes will be ascertained pragmatically via EHR-based data retrieval and will not require additional study visits. Our primary outcome is days alive and out of the hospital through day 28. Secondary outcomes include oxygen-free days; a composite of a need for advanced respiratory support or in-hospital mortality with analyses of each component separately; an ordinal measure of clinical deterioration defined by a prespecified severity scale; and 60-day and 180-day mortality. Safety outcomes are the incidence of Clostridioides difficile infection and QT prolongation. Analyses will follow an intention-to-treat framework, with per-protocol analyses for sensitivity. The primary endpoint will be compared between groups using a stratified van Elteren test, with supportive analyses using proportional odds regression and analysis of covariance adjusted for key covariates. Ethics and dissemination The Mayo Clinic Institutional Review Board reviewed and approved this protocol with a waiver of written consent, requiring verbal consent to be obtained by the clinician initiating the antibiotics (IRB# 24–0 06 503). Findings will be disseminated through peer-reviewed publications and international conference presentations. Trial registration number NCT07164131 .
Development of a shared patient registry for measles exposure management amongst multiple stakeholder groups
Olson, Alyssa, Barth, Jean, Rasmusson, Jenna, Kriewall, Nicole, Kudrna, Cory, Sheley, Todd, Kramer, Tyler, Buckmeier, Jason, OHoro, John, Rasmusson, Jenna, Kriewall, Nicole E, Buckmeier, Jason R., O’Horo, John C.

Antimicrobial Stewardship & Healthcare Epidemiology | July 17, 2026 | Volume: 6 | Issue: S1 | Pages: s189-s189

10.1017/ash.2026.10735 Get It

Background: We had a large-scale measles exposure event affecting 626 patients. Management of exposed patients was urgent, involving quarantine, post-exposure prophylaxis (PEP), and symptom monitoring on a case-by-case basis. Cases were initially tracked and managed using a combination of multiple spreadsheets amongst stakeholders as well as lists within the electronic health record (EHR). Using shared spreadsheets and lists created significant challenges with maintaining and editing multiple copies and updating workbooks simultaneously. Methods: Infection Prevention and Control (IPAC) worked with primary care personnel and EHR developers to create a shared registry that would prioritize communication and follow-up for exposed patients based on age and immunity. Patients are initially added to the shared registry within the EHR by reviewing non-registry reports and tagging patients, identified using exposure timeframes that overlapped with the index measles cases, in a manner that transferred them to the shared registry. From this registry, measles, mumps, and rubella vaccine status can be confirmed, immune status can be identified, and criteria for PEP assigned. High-risk patients are then contacted with recommendations from IPAC and primary care. Communication and follow-up are tracked directly within the shared registry to ensure appropriate patient management. The exposure management registry is further leveraged throughout the measles outbreak timeframe by allowing real-time monitoring of patients that require additional precautions or guidance related to their exposure. Result: The shared registry enhanced documentation accuracy and transparency between stakeholders. It led to availability of real-time status of exposed patients for the duration of the measles outbreak timeframe. Overall, the registry enabled time-sensitive patient communication to all exposed patients and rapid identification of those who needed PEP. Communication could happen rapidly and seamlessly between care teams within the organization, and the necessary information could be shared quickly with public health authorities as required. Conclusion: Large scale exposures are a challenge to manage and ensure appropriate action and communication occurs. Errors can be prevented by having a single shared exposure management registry. A registry enables care teams to quickly identify and prioritize patients for measles follow-up, communication, PEP, and ongoing management across outbreak timeframes. This process reduces both time and operational burdens of exposure follow-up tracking outside of the EHR.
Prevention of Secondary Cases after a Measles Exposure at an Academic Medical Center
Barth, Jean, Siple, Leah, Olson, Alyssa, Rasmusson, Jenna, Faller, Rebecca, Meyer, Michelle, Baxter, Becky, Loberg, Emily, Apenhorst, Debra, Higbe, Leah, Mahler, Sarah Bellows, Maurer, Sheryl, Whitehurst, Heidi, Paden, Felice, Higbe, Sheila, OHoro, John, Levy, Emily, Huskins, W. Charles, Sampathkumar, Priya , Rasmusson, Jenna, Apenhorst, Debra, Beam, Elena , O’Horo, John C. , Huskins, W. Charles

Antimicrobial Stewardship & Healthcare Epidemiology | July 17, 2026 | Volume: 6 | Issue: S1 | Pages: s176-s176

10.1017/ash.2026.10710 Get It

Background: Measles is a highly transmissible virus. A single case can result in significant exposures within a healthcare facility and prompt action is needed to prevent secondary cases. In October 2025, Infection Prevention and Control (IPAC) was notified of a patient being admitted to our facility with recent international travel and symptoms consistent with measles. The patient was unvaccinated and had five healthcare facility visits prior to measles being suspected and subsequently confirmed. Objective: To describe our facility’s effective identification, prioritization, and prophylaxis of individuals exposed to measles. Methods: IPAC leveraged the electronic medical record to identify potentially exposed patients. Patients were quickly assessed for age and immune status, then prioritized and assigned to primary care teams. These teams promptly contacted patients and coordinated PEP administration. Results: Across five encounters, the index patient exposed 539 other patients. Due to delayed notification, our teams had less than four days to administer PEP for those exposed and still within PEP window. PEP administration began within hours of the index case’s positive test and patients received PEP within three days (Table 1). No secondary measles cases occurred within our facility. Conclusion: Timely and coordinated multidisciplinary effort enabled us to rapidly respond to our first measles case and control secondary transmission. Although the index case resulted in a large exposure, patients that were exposed and eligible for PEP were quickly prioritized to prevent secondary transmission.
Performance Improvement in Healthcare Facility Measles Management
Siple, Leah, Barth, Jean, Faller, Rebecca, Olson, Alyssa, Rasmusson, Jenna, Meyer, Michelle, Baxter, Becky, Loberg, Emily, Higbe, Leah, Apenhorst, Debra, Mahler, Sarah Bellows, OHoro, John, Levy, Emily, Huskins, W. Charles, Sampathkumar, Priya , Rasmusson, Jenna, Apenhorst, Debra, Beam, Elena , O’Horo, John C. , Huskins, W. Charles

Antimicrobial Stewardship & Healthcare Epidemiology | July 17, 2026 | Volume: 6 | Issue: S1 | Pages: s154-s155

10.1017/ash.2026.10679 Get It

Background: Advanced planning and adaptable response strategies are essential for preventing measles transmission in healthcare facilities. Objective: To describe a measles management plan and subsequent modifications in response to a cluster of measles cases. Methods: Drawing on previously published work (doi:10.1017/ice.2025.49), the Infection Prevention and Control (IPAC) team initiated a multi-disciplinary team and developed a measles preparedness plan with the following domains: Guidance and education; early detection and testing; isolation and patient movement; contact tracing and exposure management (Table 1). In October 2025, a patient was admitted during their fifth healthcare encounter and was diagnosed with measles. Two family members were later hospitalized with measles. Delayed recognition of the first case prompted enhancements to our preparedness framework (Table 1). Results: The first case resulted in 539 exposed patients. The second resulted in 87 exposures, and the third resulted in no exposure. Despite the extensive exposure, zero secondary measles were reported. Conclusion: Proactive planning enabled rapid response to our first case and controlled secondary transmission. Despite extensive planning, delayed identification of the first case caused significant exposures. As the cluster unfolded, we refined our plan, resulting in zero exposures from the last patient and zero secondary cases, despite over 850 exposures. These efforts may guide other healthcare facilities in improving their measles preparedness and response.
Developing a Measles Flagging System within the Electronic Health Record
Rasmusson, Jenna, Sampathkumar, Priya , OHoro, John, Barth, Jean, Olson, Alyssa, Nelson, Ben, Faller, Rebecca, Siple, Leah, Rasmusson, Jenna, O’Horo, John C.

Antimicrobial Stewardship & Healthcare Epidemiology | July 17, 2026 | Volume: 6 | Issue: S1 | Pages: s154-s154

10.1017/ash.2026.10678 Get It

Background: In 2025, 50 measles outbreaks drove 87% of confirmed cases reported in the United States. As a highly infectious virus with an estimated R ranging from 12-18, we sought rapidly scalable and implementable measles preparedness measures for our facilities. Methods: The electronic health record (EHR) has flags that can be placed on patient records to denote the presence of, or concern for, active, transmissible infections. These flags are highly visible in the EHR and represent a good usability heuristic as front line providers are already trained to look for this information. Infection Prevention and Control (IPAC) worked with nursing informatics to develop measles-specific flags for suspected, confirmed and exposed patients in the EHR, expanding flagging functionality in preparation for potential measles cases and exposures. The flagging was tied to registry functionality to allow for tracking of exposed and confirmed cases longitudinally for supporting IPAC investigations in addition to clinical operations. Results: Three different flags were developed in the EHR to address measles. Specific criteria were created for each flag, as shown in Table 1. Table 1: Attached as Image Conclusion: As a highly contagious virus, measles presents unique challenges to healthcare facilities managing both cases and exposures. Measles flags within the EHR can be leveraged to assist facilities with case tracking, exposure management, and infection prevention and control.
P-1039. Cost of CAUTI: A Retrospective Study of 314 catheterized patients
Garcia, Bismarck Bisono, Nadeem, Saffa, Katragadda, Silpita , O’Horo, John C.

Open Forum Infectious Diseases | January 12, 2026 | Volume: 13 | Issue: Supplement_1 | Pages: No page available

10.1093/ofid/ofaf695.1234 Get It

Abstract Background Catheter-associated urinary tract infection (CAUTI) is one of the most prevalent nosocomial infection reported and is associated with significant resource expenditure across health care facilities. Methods We conducted a retrospective review of newly catheterized patients at a tertiary hospital over 12-months period. Demographic, clinical, and diagnostic data were collected. Based on the National Health Safety Network (NHSN) criteria, patients were divided into two groups: health care associated infection (HAI) and criteria not met (CNM). Outcome measures included secondary bloodstream infections, hospital re-admission, death, and microbiological relapse at 30 days of hospital discharge. These outcomes were compared between groups. Results A total of 314 patients were identified, of whom 55 (17.5%) met the criteria for HAI. Demographic, clinical and microbiological data are summarized in Tables 1-3. In comparison to the CNM group, the HAI group showed higher rates of fever, urinary frequency, bladder pain or tenderness, costovertebral angle tenderness, positive blood cultures, growth of urinary microorganisms >100,000 colony forming units (CFU), and imaging evidence of infection (p< 0.01). Blood stream infections were observed in 20 (6.6%) patients, with 12 of these in the HAI group, and were attributed to a urinary source in 7 cases. Composite outcomes were affected by fever (p< 0.01), imaging evidence of infection (p< 0.01) and presence of renal abscess, whereas the age of catheter, dysuria, bladder tenderness, urinary frequency, urinary CFU threshold didn't achieve statistical significance. After adjusting for the Charlson Comorbidity Index, the HAI group showed higher rates of re-occurrence of blood stream infections, re-admission and mortality within 30 days (Table 4). Conclusion Fever, imaging evidence of infection, and renal abscess were significant predictors of adverse composite outcomes, whereas catheter age, dysuria, bladder tenderness, urinary frequency, and urinary CFU threshold were not. Refinement of the NHSN surveillance definition of CAUTI may enhance targeted resource allocation for prevention efforts. Disclosures All Authors: No reported disclosures
Clinical Practice Guidelines by Infectious Diseases Society of America 2025 Guidelines on Management and Treatment of Complicated Urinary Tract Infections--Introduction and Methods
Trautner, Barbara W. , Cortés-Penfield, Nicolás , Gupta, Kalpana , Moran, Gregory J. , Colgan, Richard, Ashraf, Muhammad Salman , Connolly, S.J., Grigoryan, Larissa, Nicolle, Lindsay, Schaeffer, A J, Yawetz, Sigal, Lavergne, Valéry , Grigoryan, Larissa , Grigoryan, Larissa , Schaeffer, Anthony , Hirsch, Elizabeth B. , Horstman, Molly J. , O’Horo, John C. , Drekonja, Dimitri Maximilian , Huttner, Angela , Lazenby, Gweneth B. , Nicolle, Lindsay E., Schaeffer, Anthony

Clinical Infectious Diseases | December 11, 2025 | Volume: 82 | Issue: Supplement_3 | Pages: i24-i35

10.1093/cid/ciaf459 Get It

Clinical Practice Guidelines by Infectious Diseases Society of America: 2025 Guidelines on Management and Treatment of Complicated Urinary Tract Infections – Timing of Intravenous to Oral Antibiotics Transition for Complicated Urinary Tract Infections
Trautner, Barbara W. , Cortés-Penfield, Nicolás , Gupta, Kalpana , Moran, Gregory J. , Colgan, Richard, Ashraf, Muhammad Shamvil, Connolly, S.J., Grigoryan, Larissa , Lazenby, Gweneth B. , Nicolle, Lindsay E., Schaeffer, Anthony , Yawetz, Sigal, Lavergne, Valéry , Grigoryan, Larissa , Schaeffer, Anthony , Gupta, Kalpana , Hirsch, Elizabeth B. , Horstman, Molly J. , O’Horo, John C. , Ashraf, Muhammad S, Drekonja, Dimitri Maximilian , Huttner, Angela

Clinical Infectious Diseases | December 11, 2025 | Volume: 82 | Issue: Supplement_3 | Pages: i68-i78

10.1093/cid/ciaf461 Get It

Abstract Background These recommendations provide guidance on the optimal timing for transitioning from intravenous to oral antibiotics in patients with complicated urinary tract infection (cUTI), especially in presence of associated Gram-negative bacteremia. Methods The panel's recommendations are based upon evidence derived from systematic literature reviews which focused on comparative benefits and harms of transitioning to oral therapy versus continuing parenteral therapy of the total duration of treatment, including publications since 2000. These recommendations adhere to a standardized methodology for rating the certainty of evidence and strength of recommendation according to the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Results The guidelines panel suggests transitioning to oral antibiotics in patients with cUTI who are clinically improving, able to take medication, and for whom an effective oral option is available, rather than continuing parenteral therapy for the remaining treatment duration, regardless of the presence of associated Gram-negative bacteremia. An effective oral option needs to be active against the causative pathogen and achieve therapeutic levels in the urine and relevant tissue. Conclusions Parenteral and oral antibiotics used to complete treatment courses for cUTI provide similar efficacy and adverse events, especially in the context of shorter duration of therapy. This recommendation places a high value on reducing avoidable intravenous catheter-related adverse events, costs, and resources, as well as taking into account practical aspects of antibiotic administration.
Clinical Practice Guidelines by Infectious Diseases Society of America (IDSA): 2025 Guidelines on Management and Treatment of Complicated Urinary Tract Infections--Duration of Antibiotics for Complicated UTI
Trautner, Barbara W. , Cortés-Penfield, Nicolás , Gupta, Kalpana , Horstman, Molly J. , Moran, Gregory J. , Colgan, Richard, Ashraf, Muhammad Shamvil, Connolly, S.J., Grigoryan, Larissa , Lazenby, Gweneth B. , Nicolle, Lindsay E., Schaeffer, Anthony , Yawetz, Sigal, Lavergne, Valéry , Grigoryan, Larissa , Schaeffer, Anthony , Gupta, Kalpana , Hirsch, Elizabeth B. , O’Horo, John C. , Ashraf, Muhammad S, Drekonja, Dimitri Maximilian , Huttner, Angela

Clinical Infectious Diseases | December 11, 2025 | Volume: 82 | Issue: Supplement_3 | Pages: i79-i88

10.1093/cid/ciaf462 Get It

Abstract Background These recommendations provide guidance on the optimal duration of antibiotics in patients with complicated urinary tract infection (cUTI), especially in presence of associated Gram-negative bacteremia. Methods The panel's recommendations are based upon evidence derived from systematic literature reviews which focused on comparative benefits and harms of shorter (5–7 days) vs prolonged (10–14 days) duration of antibiotics, including publications since 2000. These recommendations adhere to a standardized methodology for rating the certainty of evidence and strength of recommendation according to the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Results The guidelines panel suggests that patients with cUTI who are improving on effective therapy can be treated with shorter duration of antimicrobials (either 5–7 days of a fluoroquinolone or 7 days of a non-fluoroquinolone) rather than longer courses of antibiotics, regardless of the presence of associated Gram-negative bacteremia. An effective antimicrobial agent achieves therapeutic levels in the urine and relevant tissue and is active against the causative pathogen. However, men with febrile UTI in whom acute bacterial prostatitis is suspected may benefit from a longer treatment duration (10–14 days), and a short courses of oral beta lactams may require higher doses for efficacy. Conclusions Shorter durations of antibiotics for cUTI provide similar efficacy as longer courses, except in men with febrile UTI in whom acute bacterial prostatitis is suspected. This recommendation places a high value on antibiotic stewardship considerations as well as reducing the burden of antimicrobial administration from a healthcare perspective and reducing the burden of taking antibiotics from a patient perspective.