Leadership
Our Director
Dr. Thomas Walsh is an internationally distinguished physician-scientist, clinician, scholar, mentor, educator, and humanitarian, who serves as Founding Director of the Center for Innovative Therapeutics and Diagnostics (citdx.org), the Henry Schueler Foundation Scholar in Mucormycosis, Investigator of the Save Our Sick Kids Foundation, Adjunct Professor of Pathology of the Johns Hopkins University School of Medicine, and Adjunct Professor of Medicine and Microbiology & Immunology of the University of Maryland School of Medicine. He also serves as Visiting Professor in Infectious Diseases and Medical Mycology, Aristotle University School of Medicine, and Visiting Professor in the National and Kapodistrian University of Athens School of Medicine.
After receiving his M.D. (AΩA, ΦΒΚ) at The Johns Hopkins University School of Medicine, Baltimore, MD, Dr. Walsh trained over 10 post-doctoral years in infectious diseases, antimicrobial pharmacology, medical mycology, innate host defenses, pathology, and oncology at Johns Hopkins University, University of Maryland, and the National Cancer Institute, leading to board-certification in Medicine, Infectious Diseases, and Oncology. During his 23 years at the National Cancer Institute in Bethesda, MD, Dr. Walsh became the Chief of the Immunocompromised Host Section in the Pediatric Oncology Branch, where he directed a combined laboratory and clinical translational research program dedicated to the pharmacotherapeutics, immunopharmacology, and molecular detection of invasive fungal diseases in pediatric and adult patients with cancer, hematopoietic cell transplantation, and HIV infection. Following nearly a quarter century of dedicated government service, Dr. Walsh was recruited to serve in 2010 as the Founding Director of the first Weill Cornell/New York Presbyterian Hospital Transplantation-Oncology Infectious Diseases Program, where over 12 years, as Professor of Medicine, Pediatrics, Microbiology & Immunology, he led the development of the Transplantation-Oncology Infectious Diseases Program consisting of a leading-edge Translational Research Laboratory, highly productive Clinical Research Unit (CRU), and expert Patient Care Service, as well as having introduced major educational and mentoring initiatives, and providing direct compassionate patient care.
As the author of more than 1,100 publications and investigator for more than 100 clinical protocols, he and his colleagues have laid the scientific foundation for major advances and standards of care in diagnosis, treatment, and prevention of invasive mycoses in immunocompromised pediatric and adult patients with cancer, hematopoietic cell transplantation, and other immunocompromised conditions. His translational research is responsible for elucidating the pharmacological and therapeutic properties of virtually every major systemic antifungal agent currently used in pediatric and adult patients for life-threatening mycoses. In response to the global public health crisis of multidrug resistant Gram-negative bacterial infections, he and his staff further expanded their clinical research and laboratory investigations to develop new antimicrobial therapeutic agents in novel preclinical model systems leading to clinical trials against these life-threatening diseases. In summary, Dr. Walsh’s translational research from laboratory to clinic trials to standards of care has greatly advanced sciences and saved the lives of numerous immunocompromised patients worldwide.
Teaching and Mentoring
Dr. Walsh has mentored more than 200 students, residents, post-doctoral fellows, microbiologists, medical mycologists, pharmacists, immunologists, nurses, technologists, and junior faculty from 39 different countries in the fields of Medical Mycology, Microbiology, Immunology, Pharmacology, and Infectious Diseases. Sixty-two mentees are members of historically disadvantaged minorities and 116 are women. Many are now emerging or established leaders, including program directors, division chiefs, and department chairs, in the fields of antimicrobial pharmacology, antifungal therapeutics, medical mycology, host defenses, clinical microbiology, immunology, and infectious diseases with particular focus on invasive fungal infections and multidrug resistant bacterial infections, as Associate Professors or full Professors of Pediatrics, Medicine, Pathology, Microbiology, Immunology, and Pharmacy in leading universities, while other mentees have achieved important leadership roles in the USPHS, NIH, FDA, and EMA.
During the past two decades, Dr. Walsh has served as mentor or co-mentor on six K-23 and K-08 awards to University medical center junior faculty, all of whom have made stellar achievements in the fields of pediatrics, medicine, antimicrobial pharmacology, microbiology, immunology, pathology, and epidemiology, including Awards from the American Society for Microbiology, Children’s Oncology Group, and Pediatric infectious Diseases Society.
Dr. Walsh’s dedicated mentoring and inspiring clinical teaching in Medical Mycology, Microbiology, Host Defenses, Pharmacology, and clinical Infectious Diseases has been recognized through numerous awards and stellar student evaluations. During the past three decades, Dr. Walsh has taught more than 9,000 medical students and graduate students in his lecture series at Johns Hopkins University, University of Maryland, and Weill Cornell Schools of Medicine.
Dr. Walsh’s profound impact in teaching and mentoring a generation of clinicians and scientists resonates in the words of one of his mentees, who said, “My mentor was the making of who I am.” Other mentees recently shared, “I deeply thank you for your support and thoughtful mentorship over the years, as you have been a big part of why I received this award. I hope that I can be as good of a mentor to others as you have been to me.”
Antifungal Pharmacology and Therapeutics
Within the field of antifungal pharmacology and experimental therapeutics, Dr. Walsh and his team have methodically investigated the pharmacology, experimental therapeutics, and clinical activity of all major classes of antifungal agents (polyenes, lipid formulations, triazoles, and echinocandins), as well as numerous experimental classes.
Dr. Walsh co-founded a consortium of colleagues and pediatric institutions, which conducted the critical studies of safety, tolerability, and pharmacokinetics of 10 systemic antifungal agents. These studies were essential for the treatment of life-threatening fungal diseases in pediatric patients worldwide, as well as for their regulatory approval for their use in treatment and prevention of mycoses in children. Through his organizing abilities, expertise, and vision, this consortium systematically studied the safety and pharmacokinetics of all of the major systemic antifungal agents for life-saving treatment of life-threatening infections in immunocompromised children during the past three decades: amphotericin B lipid complex, liposomal amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole, caspofungin, micafungin, and anidulafungin. The result of this translational research has provided pediatricians worldwide with the knowledge of the dosage, safety, and efficacy in pediatric patients for the treatment of life-threatening invasive fungal diseases. Dr. Walsh also founded a consortium of 30 institutions that conducted landmark phase II and phase III clinical trials for treatment and prevention of invasive fungal diseases in adult patients with hematological malignancies and hematopoietic cell transplantation (HCT). These clinical studies were grounded in strong preclinical and translational research foundations from Dr. Walsh’s laboratory. During the past three decades, he and his staff have developed 27 rabbit models of invasive pulmonary, disseminated, CNS, esophageal, gastrointestinal, oropharyngeal and catheter-related infections that closely replicate the profoundly immunocompromised patients with neutropenia or stem cell transplant in our oncology/HCT population. The models of primary pulmonary aspergillosis, fusariosis, mucormycosis, scedosporiosis, Exserohilum rostratum meningitis, as well as disseminated and catheter related models of invasive candidiasis, and trichosporonosis are microbiologically, histologically, immunologically, and radiologically highly replicative of the conditions of which are encounter in patients. The antifungal activities in these novel model systems have laid the foundation for and have been predictive of the therapeutic outcome in numerous clinical trials, which in turn have revolutionized antifungal therapy over the past quarter century against these lethal fungal diseases.
Molecular Biomarkers for Diagnosis and Therapeutic Response
Beginning with the first detailed description of the correlation between responses of galactomannan antigenemia to antifungal therapy in experimental invasive pulmonary aspergillosis in 1992, he and his co-workers have systematically characterized the in vitro and in vivo factors contributing to the expression circulating enolase, D-arabinitol, galactomannan, non-Aspergillus galactomannan, D-mannitol, (1→3)-β-D-glucan, glucuronoxylomannan, and molecular and circulating DNA with genes of the ItS-1, ITS-2, 5.8S, 18S, and 28S regions the rRNA operon, as well as new proteomic markers. Proceeding from bench-to-bedside, he and his colleagues have studied these biomarkers in patients with invasive candidiasis, CNS Candida infections, pulmonary aspergillosis, and pulmonary mucormycosis. Their PCR assays have been adapted for several platforms for direct patient care. Dr. Walsh and his team were the first to preclinically characterize serum galactomannan as a biomarker for detection and therapeutic monitoring of invasive pulmonary aspergillosis. He and his staff also were the first to demonstrate CSF (1→3)-β-D-glucan as a biomarker for invasive fungal disease of the central nervous system. Further studies using magnetic resonance assays, cell free metagenomic platforms, and point-of-care systems are helping to identify sepsis and invasive fungal diseases earlier in the course of infection to allow for targeted antifungal therapy, as well as for the rapid detection of antimicrobial resistance.
Immunopharmacology and Host Defenses
Dr. Walsh’s Laboratory has laid important foundations in our understanding of the role of the immunopharmacology of cytokines, immune augmentation of innate host defense and their relation to antifungal chemotherapy. Working in collaboration with Dr. Emmanuel Roilides and colleagues from several laboratories, Dr. Walsh’s Program elucidated and documented the functional biology of G-CSF, GM-CSF, M-CSF, interferon–γ, TNF-α, TGF-β, IL-13, IL-10, IL-8, IL-4 and other molecules in augmenting, suppressing, or modulating innate host response of neutrophils, monocytes, monocyte-derived macrophages, and pulmonary alveolar macrophages against Candida spp., Aspergillus spp., Mucorales, Fusarium spp., Scedosporium spp., and Exserohilum rostratum. They have characterized elements of the signal transduction pathways of these cytokines and have demonstrated the role of rhuG-CSF, rhuGM-CSF and interferon–γ in reversing corticosteroid induced immunosuppression of monocytes, macrophages, and neutrophils. Understanding the immune activation properties of small molecule antifungal compounds has provided novel insight into their mechanisms of action. These pioneering studies have led to key clinical advances and new initiatives in host-directed immunotherapeutics in children and adults with refractory invasive fungal diseases.
Multidrug Resistant Bacterial Infections
Dr. Walsh and his team have responded robustly to the rapidly emerging public health threat of multidrug resistant (MDR) Gram-negative bacterial infections through laboratory investigation and clinical research to develop new antimicrobial therapeutic agents and strategies in novel model systems leading to clinical trials to combat these life-threatening diseases. Using highly predictive rabbit model systems of Pseudomonas aeruginosa, Klebsiella pneumoniae (KPC), Acinetobacter baumannii, and Stenotrophomonas maltophilia pneumonia, and MRSA catheter bloodstream infection, we are investigating new antimicrobial agents in the battle against MDR organisms. They are also harnessing the power of bacteriophages using the whole virus, as well as their purified lytic enzymes, to treat disseminated MDR infections in murine models and pneumonias in rabbit models. The data from these models are leading to new clinical protocols for treatment of these infections in patients.
Translational Antimicrobial Development
Dr. Walsh and his team through their translational research efforts have contributed to the preclinical and clinical research of 19 antimicrobial agents from bench to bedside in pediatric and/or adult patients: amphotericin B, amphotericin B lipid complex, liposomal amphotericin B, flucytosine, caspofungin, micafungin, anidulafungin, fluconazole, itraconazole, voriconazole, posaconazole, ravuconazole, isavuconazole, ibrexafungerp, novobiocin/rifampin, trimethoprim/sulfamethoxazole, ceftazidime, ceftazidime/avibactam, and ceftolozane/tazobactam, and cefiderocol.
COVID-19
During the period from 2020-2022, Dr. Walsh and his team responded robustly to the challenges of COVID-19. These responses included direct care of the most seriously ill hospitalized patients, particularly during the apogee of the pandemic in 2020. Clinical research protocols investigated by the Clinical Research Unit include the epidemiology, clinical manifestations, host defenses, molecular detection, and innovative therapeutics, which include remdesivir, monoclonal antibodies, convalescent plasma, host response, and a wide range of immunomodulators investigated through industry and NIH sponsored grants. Dr. Walsh also served on the Weill Cornell COVID-19 Clinical Research Task Force, which helped to guide implementation of clinical trials for treatment of COVID-19. Further work supported by the Hellenic/American Fellowship/Mentorship, AHEPA, and the Henry Schueler 41&9 Foundation has identified a new class of orally bioavailable small molecules (thiadiazoles and benzothiazoles) that are potent inhibitors of the SARS-CoV-2 main protease. Dr. Walsh and his team also served as educator resource of COVID-19 to numerous medical, institutional, industrial, and lay communities.
Citation Indices and Metric
Dr. Walsh’s work has been extensively cited in the biomedical literature. Ranked among the most highly cited investigators in microbiology and medical mycology, his publications have received 149,930 citations with an h-index of 174 and an i10 index of 849 as of January 31, 2026.
Organizational Leadership
Dr. Walsh has demonstrated outstanding leadership throughout his career in many related areas of Infectious Diseases. He has served as President and Councilor of the MMSA, Councilor of the International Immunocompromised Host Society, Chair and Councilor of the Medical Mycology Division of the ASM, and as President of the Medical Mycological Society of New York (MMSNY). He has organized and chaired numerous educational sessions at national and international meetings, chaired working groups within the NIAID MSG and BAMSG, served on editorial boards and as reviewer for numerous journals in infectious diseases and medical mycology, co-chaired the IDSA Guidelines Committees for Aspergillosis, served on multiple national and international grant review committees, organized the first two Henry Schueler Foundation International Forum on Mucormycosis, chaired the CPIC Guideline Committee on implementation of genotypic data guiding the use of voriconazole, and co-founded International Consortium for Study of Osteoarticular Mycoses with Institute Pasteur in France.
Emergency and Humanitarian Response to National and Regional Disasters and Service to Local Communities
Dr. Walsh has responded to numerous disasters and provided critically needed outreach service to his community over the past three decades. He served in an emergency capacity in the care of patients on September 11, 2001 in New York City following the terrorist attack on the World Trade Center, provided direct medical care and evaluations of children and adults who were exposed to anthrax in the attack on the Brentwood Postal Office in Washington DC, served as incident commander for the field hospital at the Ronald Regan Funeral, deployed and served as immunization team leader for victims of Hurricane Katrina and as incident medical commander for victims of Hurricane Rita in Louisiana with the USPHS. He also served the victims of Hurricanes Irene and Sandy with the New York City Medical Reserve Corps. Dr. Walsh also founded and currently directs an annual faith-based regional clothing and food drive known as CASA (Clothing and Sustenance for All), which has provided multiple tons of clothing and food for destitute and homeless adults and children. He most recently co-coordinated for CASA 2024-2025 a multi-state, church-based humanitarian mission to collect, deliver, and distribute rescue supplies (food, clothing, blankets, and supplies) for the destitute families of Hurricane Helene in Western North Carolina, many of whom were still living in tents in freezing weather.
Clinical Resource and Dedicated Service to Patients
Dr. Walsh serves as a key institutional, national, and international expert in the care of pediatric and adult patients with invasive fungal diseases and other opportunistic infections. Dr. Walsh provides state of the art, advanced, and compassionate care to immunocompromised patients with a wide range of infectious diseases. For nearly four decades, he has directly impacted on the lives of several thousand individual patients with life-threatening mycoses and other serious infectious diseases. Dr. Walsh also has contributed his expertise in bringing the best advances from bench to bedside in outreach care of more than 1,100 pediatric and adult patients with life-threatening mycoses from more than 280 health care institutions in the United States and 94 medical centers from 38 other countries. Many of the physicians caring for these patients and their families have stated that Dr. Walsh’s intervention and guidance were essential for the survival and successful outcome of their patients and loved ones: www.missionfromtheheart.org.