Overview
My research focuses on the pathogenesis, prevention, and treatment of HIV and tuberculosis in resource poor settings including Haiti and Tanzania. The training of United States and international physician scientists is an integral part of my research activity.
HIV research initially focused upon treatment and prophylaxis of opportunistic infections and then transitioned to studies of antiretroviral therapy (ART). I conducted the first large trial of ART in a developing country. This study of the first one thousand patients with AIDS treated with ART in Haiti demonstrated treatment outcomes comparable to those achieved in the United States and provided rigorous scientific evidence in support of international efforts to make ART available to AIDS patients worldwide. I was also Project Director of a randomized clinical trial that demonstrated that early ART decreases mortality four-fold and decreases tuberculosis incidence by two-fold. This study prompted the World Health Organization to change international HIV treatment guidelines. I have also conducted HIV prevention trials including studies of HIV vaccines and strategies to increase male circumcision uptake. I am currently conducting research to optimize care for HIV-infected adolescents in Haiti. I am also conducting studies in Tanzania on the interactions between schistosomiasis and HIV and on the pathogenesis of HIV induced cardiovascular disease.
Tuberculosis research includes clinical trials to optimize treatment of both latent and active TB with a focus on HIV co-infected patients. I conducted a randomized clinical trial in HIV infected adults demonstrating that, after the successful treatment of tuberculosis, post-treatment isoniazid prophylaxis decreased the risk of TB recurrence 5-fold. Current translational studies aim to understand the persistence of M. tuberculosis in the human host and to develop new drugs that kill non-replicating mycobacteria. This includes studies of the efficacy of new drug candidates for treatment of M. tuberculosis.
I have also conducted empirical studies to inform ethical guidelines for the conduct of research in resource poor settings and to examine the ability of illiterate research volunteers in Haiti to understand the consent form and provide voluntary consent. Further studies established educational strategies to improve comprehension and assure voluntary participation.
Highlights
- 1Scientific reports · 2022
- 2Antimicrobial agents and chemotherapy · 2020
- 3Antimicrobial agents and chemotherapy · 2021
Publications
Funding
Active
10 grants- KPP01AI202868-06Determinants of TB Control, Relapse, and ReinfectionNational Institute of Allergy and Infectious Diseases · 2026–2031
- Co-IR01AI176943-01A1Impact of TB coinfection on HIV reservoirNational Institute of Allergy and Infectious Diseases · 2023–2028
- Co-IR01HL143788-08S1A longitudinal cohort study to evaluate cardiovascular risk factors and disease in Haiti - 2 - Foreign supplementNational Heart, Lung, and Blood Institute · 2018–2028· 3 renewals
- Co-IR01HL160332-01HIV, Sleep, Nocturnal Non-dipping, and Cardiovascular Disease: a Tanzanian CohortNational Heart, Lung, and Blood Institute · 2021–2027
- MPIP30AI168433-05Tri-Institutional Tuberculosis Research Advancement CenterNational Institute of Allergy and Infectious Diseases · 2022–2027
- PID43TW011826-05S2Mwanza-Tanzania Research Training Program in HIV Clinical Investigation (Foreign Subsite Supplement)Fogarty International Center · 2021–2027· 6 renewals
- PI75D30121C10170Tuberculosis Trials Consortium (TBTC) Clinical Research ServicesCenters for Disease Control and Prevention · 2021–2026
- MPIUM1AI069421-17GHESKIO HIV Clinical Trial Unit (CTU)National Institute of Allergy and Infectious Diseases · 2007–2026 · via GHESKIO Centers· 2 renewals
- KPU19AI162568-05S1Determinants of TB control, relapse and reinfection - Foreign Funding SupplementNational Institute of Allergy and Infectious Diseases · 2021–2026· 2 renewals
- Sub-PID43TW011295-05Research Training Program in Adolescent HIV in HaitiFogarty International Center · 2020–2025 · via GHESKIO Centers
Completed grants (24)
- Co-IR01MH118107-01Reducing Post-Hospital Mortality in HIV-Infected Adults in TanzaniaNational Institute of Mental Health · 2018–2025
- PIK24AI098627-10Global Health Research Training in HIV and TuberculosisNational Institute of Allergy and Infectious Diseases · 2012–2024· 2 renewals
- MPID43TW009337-11Vanderbilt-Emory-Cornell-Duke Consortium for Global Health Fellows (VECDor) VUMC 63328Fogarty International Center · 2017–2023 · via Vanderbilt University Medical Center· 6 renewals
- PISA 204457-01Amendment to Colorado Agreement (Fitzgerald)University of Colorado · 2020–2023Contract
- PIR01HD091935-04FANMI: Community Cohort Care for HIV-infected Adolescent Girls in HaitiEunice Kennedy Shriver National Institute of Child Health and Human Development · 2017–2022
- KPK23MH111409-01Expanding HIV testing among Ugandan adults who utilize traditional healersNational Institute of Mental Health · 2018–2022Career
- MPIU19AI111143-06S1Tri-Institutional TB Research Unit: Persistence and LatencyNational Institute of Allergy and Infectious Diseases · 2014–2021· 3 renewals
- MPIR25TW009337-05VUMC 58375: Vanderbilt-Emory-Cornell-Duke Consortium for Global Health Fellows (VECDor)Fogarty International Center · 2012–2021 · via Vanderbilt University Medical Center· 12 renewals
- Sub-PIR01AI124349-05Human Genetics of TB Resistance in HIV-Infected PersonsNational Institute of Allergy and Infectious Diseases · 2016–2021 · via McGill University
- PID43TW010062-05S1Research Training Program in the Diagnosis, Treatment, and Prevention of AIDS-related MDR-TB in Haiti - Supplement for Meeting AttendanceFogarty International Center · 2015–2021Training· 5 renewals
- Sub-PID43TW010138-04Strengthening Research Capacity for Junior Faculty in TanzaniaFogarty International Center · 2015–2020 · via Kilimanjaro Christian College
- KPK23AI110238-05Schistosomiasis, Mucosal Immunity, and HIV SusceptibilityNational Institute of Allergy and Infectious Diseases · 2014–2020Career
- PISA 192405-01Service Agreement - FANMI/POC Adherence TestingUniversity of Colorado · 2019–2020Contract
- Co-IW81XWH-18-1-0133Urinary Biomarkers of Tuberculosis: Potential for diagnosis and beyondU.S. Department of Defense · 2018–2019
- PID43TW009606-04S1Haiti Research Training Progam in the Prevention of AIDS Cervical CancerFogarty International Center · 2013–2019· 2 renewals
- Co-IR01HD081929-04Impact of Immune Changes of Pregnancy on TuberculosisEunice Kennedy Shriver National Institute of Child Health and Human Development · 2014–2018 · via The Johns Hopkins University
- MPIU19AI111276-03Visualizing Differentially Detectable M. Tuberculosis in SputumNational Institute of Allergy and Infectious Diseases · 2015–2017 · via Boston Medical Center (Corporation)
- Sub-PIR25TW009334-04VUMC 55756: Vanderbilt-Emory-Cornell-Duke Consortium for Global Health FellowsFogarty International Center · 2015–2017 · via Vanderbilt UniversityNo publications yet
- KPU2GGH000545-05Training in Integrated HIV Clinical-Based Services - GHESKIO NetworkCenters for Disease Control and Prevention · 2011–2016 · via GHESKIO CentersNo publications yet
- PIR01CA142422-03 EWNatural History and Pathogenesis of HPV/HIV Co-Infection in HaitiNational Cancer Institute · 2010–2014
- Sub-PIU2RTW006896-10Haiti AIDS Research Training: Models to ImplementationFogarty International Center · 2009–2014 · via GHESKIO Centers
- Sub-PI5 R25 TW009337-02 (VVUMC 40295: Vanderbilt-Emory-Cornell-Duke Consortium for Global Health FellowsFogarty International Center · 2012–2014 · via Vanderbilt University
- PIR21AI064021-02AIDS Diarrhea and Antiretroviral Drug AbsorptionNIAID · 2005–2008 · via NIH RePORTER
Honors & distinctions
- Member · Association of American Physicians · 2018
- Member · American Society for Clinical Investigation · 2015
Clinical research
Completed & closed trials (1)
- PIA Longitudinal Cohort Study of HIV-negative Cavitary Tuberculosis Patients in HaitiNational Institutes of Health · CLOSED TO ACCRUAL (as of 2026)
News mentions
- Dr. Warren Johnson Honored with Weill AwardJune 4, 2025
The Weill Award recognizes an exceptional faculty member whose transformational work enhances health care worldwide.
- Diagnose to Cure: Developing RNA-based TB TestingApril 25, 2025
Weill Cornell Medicine investigators are developing a new test for TB that circumvents many of the current diagnostic challenges.
- Drug-Resistant Tuberculosis Responds Rapidly to Bedaquiline-based Second-Line TherapyFebruary 27, 2024
Patients who have drug-resistant tuberculosis (TB) have a similar microbiological response to bedaquiline-based second-line medications as patients with drug-sensitive TB taking first-line regimens, according to researchers at Weill Cornell Medicine in New York and GHESKIO in Haiti.
- $5 Million NIH Center Grant Will Support Next Generation TB ResearchSeptember 7, 2022
Weill Cornell Medicine has been awarded a five-year, $5 million grant from the National Institutes of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health to establish a new multi-institutional center for tuberculosis (TB) research and training the next generation of TB investigators.
- Partnering with Traditional Healers Improves Uptake of HIV Tests in Rural UgandaOctober 19, 2021
Collaborating with traditional healers to deliver point-of-care HIV tests to individuals in rural Uganda quadrupled testing rates compared with standard referrals to HIV clinics.
Show 4 more mentions
- Study Illuminates Role of Gut Microbes in the Response to TB TreatmentMarch 10, 2021
Gut bacteria play an important role in the body’s response to treatment for tuberculosis (TB), according to researchers at Weill Cornell Medicine and Memorial Sloan Kettering.
- Weill Cornell Medicine Establishes Office of International Affairs, Led by Dr. Michael G. StewartFebruary 21, 2020
Dr. Michael G. Stewart, an esteemed clinician and leader, has been appointed senior associate dean for international affairs and affiliations and is leading both the Office of International Affairs and the Office of Affiliations, which manages the institution’s affiliations with academic medical centers and healthcare organizations nationwide.
- Weill Cornell Faculty Member Honored with International Award in MedicineJune 25, 2019
Dr. Robert Peck, an assistant professor of medicine and of pediatrics at Weill Cornell Medicine, has been awarded the 2019 Dr. Nathan Davis International Award in Medicine by the American Medical Association Foundation.
- Coordinated Action Needed to Fix the Gender Gap in Global Health Leadership, Study SaysMarch 1, 2019
Despite comprising up to 80 percent of global health faculty members and workers, women hold only a fraction of global health leadership roles.
Mentoring
- KLKatherine LiMD mentee · Class of 2019