Michael Charles
· Cornell Provost’s New Faculty Fellow and Assistant ProfessorVerifiedCornell University · Biological and Environmental Engineering
Active 1996–2026
About
Dr. Michael Charles is an Assistant Professor in the Department of Biological and Environmental Engineering at Cornell University. He also serves as an Affiliate Faculty member of the American Indian and Indigenous Studies Program and is a Faculty Fellow of the Cornell Atkinson Center for Sustainability. Dr. Charles earned his B.S. in Chemical and Biomolecular Engineering from Cornell University, followed by his M.S. and Ph.D. in the same field from The Ohio State University. His research expertise centers on developing computational sustainability frameworks that incorporate dynamic ecological models. As a Diné (Navajo) scholar, he is committed to establishing mutually respectful partnerships with Indigenous communities. His vision integrates engineering fundamentals, computational methods, and community-centered relationships to translate research into actionable outcomes. Beyond his academic research, Dr. Charles actively collaborates with the International Indigenous Peoples’ Forum on Climate Change, advocating for Indigenous rights, leadership, and self-determination within United Nations Climate Negotiations.
Research topics
- Medicine
- Computer Science
- Demography
- Virology
- Biology
- Sociology
- Cartography
- Archaeology
- Geography
- Genetics
- Environmental health
- Immunology
- Pathology
Selected publications
The Lancet Infectious Diseases · 2026-05-01
articleOpen accessBACKGROUND: The extensive genetic diversity of HIV presents major challenges to treatment and prevention. We aimed to estimate the global and regional distribution of HIV-1 subtypes and recombinants during 1990-2024. METHODS: We conducted a systematic literature review by searching PubMed, Embase, Global Health, and CINAHL for country-specific HIV-1 subtyping data published between Jan 1, 2022, and Jan 22, 2025, and a global survey of the Global HIV Molecular Epidemiology Collaboration for unpublished data collected between 2016 and 2024. We included primary HIV-1 subtyping data with ≥20 samples and known country and years of sample collection during 1990-2024. We excluded publications and survey responses that had no or incomplete subtyping data, were restricted to specific HIV-1 variants, included superinfections, or used secondary data. These data were combined with HIV-1 subtyping data previously collected between 1990 and 2021. Data were aggregated by country for six time periods (1990-99, 2000-04, 2005-09, 2010-14, 2015-19, and 2020-24). Proportions of HIV-1 subtypes, circulating recombinant forms (CRFs), and unique recombinant forms (URFs) were calculated by country and period and were weighted using UNAIDS country estimates of numbers of people living with HIV to estimate regional and global HIV-1 variant proportions. The systematic review is registered with PROSPERO, CRD42017067164. FINDINGS: HIV-1 subtyping data were available for 1 395 222 samples from 154 countries during 1990-2024. In 2020-24, subtype C accounted for 48·7% (95% CI 48·3-49·1) of global HIV-1 infections, followed by subtype A (11·5%; 10·9-12·1), subtype B (10·3%; 10·0-10·5) URFs (5·3%; 4·4-6·3), CRF02_AG (5·1%; 4·5-5·8), CRF01_AE (5·1%; 4·8-5·4), other CRFs (3·9%; 3·3-4·5), subtype G (3·1%; 2·1-4·1), subtype D (3·0%; 2·7-3·3), and CRF07_BC (2·1%; 2·0-2·1). Subtypes F, H, J, K, and L combined accounted for 1·1% of infections and unspecified recombinants for 0·9% (0·7-1·0). HIV-1 variants are differentially distributed across regions, with subtype C dominating in southern Africa; Ethiopia, Eritrea, and Djibouti; and south Asia; subtype A in east Africa and eastern Europe and central Asia; subtype B in North America, Latin America, and western and central Europe; CRF01_AE in southeast Asia; and CRF07_BC in east Asia. Central Africa exhibited the greatest HIV-1 diversity. Global HIV-1 variant distributions were broadly stable during 2000-24, but notable regional changes included increases of HIV-1 recombinants in western and central Europe and of CRF07_BC in east Asia. INTERPRETATION: Global and regional HIV-1 genetic diversity is complex and evolving, affecting the efficacy of diagnostic and viral load assays, emergence of drug resistance, and vaccine development. Continued surveillance of spatiotemporal trends in HIV-1 genetic diversity is essential. FUNDING: Nuffield Department of Population Health, University of Oxford, UK.
International Journal of STD & AIDS · 2026-01-24
articleOpen accessBackground Tuberculosis (TB) is the leading cause of death among people living with HIV (PLHIV). Globally in 2023, an estimated 161,000 PLHIV died of TB. TB preventive treatment (TPT) can reduce TB mortality yet scale up remains a challenge. We documented Zimbabwe’s experience in scaling TPT among PLHIV. Methodology We analyzed routine aggregate data from the President Emergency Plan for AIDS Relief (PEPEFAR) database, Data for Accountability Transparency and Impact Monitoring (DATIM). We conducted a desk review of national guidelines, reports, training manuals, policy and strategic plans. Program reports were reviewed to understand scale up best practices, successes and challenges. Results TPT coverage (cumulative number completed TPT divided by PLHIV on ART) increased from <1% (144/950,235) in 2018 to 101% (1,040,460/1,029,583) in 2024, in PEPFAR supported health facilities. Adults had a higher TPT coverage of 102% (1,006,544/990,818) than children 87% (33,916/38,765). TPT completion (number started TPT divided number completing TPT) was significantly higher among adults, 99.2% compared to children, 97.9%, difference 1.2 percentage points (CI 0.98-1.50, p < 0.01). Key interventions resulting in improved TPT coverage and completion, included removal of the 3-months waiting period for PLHIV to initiate TPT, introduction of shorter regimens, pharmacovigilance, implementation monitoring, stakeholder engagement, and communication of updated policies. Conclusion We report a significant increase in TPT coverage and completion rates. We observed lower TPT coverage and completion among children compared to adults. TPT scale-up lessons from Zimbabwe can inform TPT expansion in countries of similar context.
Observational Studies · 2025-01-01
articleOpen accessDespite data from randomized trials demonstrating the benefits of tuberculosis preventive treatment (TPT) for people living with HIV, there remain gaps in the large-scale programmatic provision of TPT and understanding of its impact. The PROTECT study is a multi-country study that aims to evaluate the effectiveness of TPT programs on tuberculosis incidence and mortality. The study leverages electronic health records, which poses challenges in the design, analysis, and interpretation of the data. In this work, we describe the general analysis approach that will be adopted across countries for evaluation of the effectiveness of TPT programs.
Tropical Medicine and Infectious Disease · 2025-10-27
articleOpen accessTuberculosis preventive treatment (TPT) is a mainstay for reducing the tuberculosis (TB) burden among people living with human immunodeficiency virus (PLHIV). Context-specific challenges hinder TPT uptake and completion among PLHIV. During 2022-2024, a mixed-methods design was used to evaluate the TPT cascade and explore its facilitators and barriers among PLHIV availing care from 12 PEPFAR-supported health facilities in Uganda. The quantitative component included analysis of routine programmatic data, and the qualitative component included focus group discussions and in-depth interviews with healthcare workers and PLHIV. A total of 1349 PLHIV were enrolled in the evaluation. Among PLHIV newly initiated on ART (≤3 months), 74% started TPT, and 98% of them completed it. In PLHIV already on ART, 87% had initiated TPT (76% before and 11% during this evaluation), with a treatment completion rate of 98%. The facilitators for TPT implementation included access to shorter TPT regimens, integration of services, and adherence counseling. Barriers included knowledge gaps, pill burden, TPT drug stock-outs, and documentation inconsistencies. The TPT completion rate was higher than the national target (90%), but the TPT initiation remains low. Improved access to shorter regimens, adherence counseling, better documentation, and service integration can sustain the completion rate and improve the initiation rate in Uganda and possibly elsewhere.
Hepatitis B Surface Antibody Clearance After Vaccination in People With HIV
Open Forum Infectious Diseases · 2025-12-09
articleOpen accessAbstract Background People with HIV (PWH) are at higher risk of developing chronic hepatitis B, and therefore vaccination against HBV is highly recommended. Clearance of hepatitis B surface antibody (anti-HBs) over time is poorly described in PWH. Methods We retrospectively included vaccinated PWH with anti-HBs ≥10 IU/L from the French Dat’AIDS database. Those with a cured hepatitis B were excluded. For each participant, all anti-HBs levels were collected until March 2024. Anti-HBs peak was defined as the highest anti-HBs value and corresponded to entry into the analysis. Factors associated with anti-HBs clearance below 10 IU/L were identified using a multivariable Cox model. Results 11 082 PWH were included, 4480 had peak anti-HBs levels between 10 and 99 IU/L, 3268 between 100 and 499 IU/L, 1205 between 500 and 999 IU/L, and 2129 ≥ 1000 IU/L. Median follow-up was 3.8 [1.6, 7.1] years. Antibody clearance over time was similar in the three groups with peak anti-HBs ≥100 IU/L, and significantly slower than in the group with anti-HBs &lt;100 IU/L. Peak anti-HBs level was the variable with the greatest impact on anti-HBs clearance in the multivariable analysis. Compared with participants with anti-HBs &lt;100 IU/L, having peak anti-HBs values of 100–499 IU/L, 500–999 IU/L and ≥1000 IU/L were protective factors for anti-HBs clearance, with hazard ratios of .26 [0.23, 0.30], 0.17 [0.13, 0.22] and 0.10 [0.07, 0.12], respectively, P &lt; .001. Conclusions Peak anti-HBs level is the key factor of antibody persistence in PWH. Those with anti-HBs levels below 100 IU/L should be monitored closely and considered for a booster dose.
Tropical Medicine and Infectious Disease · 2025-12-10
articleOpen accessSystematic screening of household contacts (HHCs) of people with tuberculosis (TB) and starting them on either TB treatment or tuberculosis preventive treatment (TPT) reduces TB incidence. This project supported HHC management in six health facilities in Zimbabwe through the provision of CXR services, reimbursement of transport costs for HHCs, and provision of fuel and refreshments for healthcare workers involved in contact tracing. We describe TB and TPT cascades among the HHCs of index patients with all forms of TB. We enrolled 251 index patients who listed 794 HHCs: 551 (69%) HHCs of 158 index patients were traced and 520 (94%) screened for TB. Of the 502 who were referred to clinics, 362 (72%) reached the clinic. Among 520 HHCs, 324 (62%) underwent CXR screening and 18 (5%) had CXRs suggestive of TB. The yield of TB was 2.3% (12/520), with CXR detecting eight people who had not reported TB symptoms. Of the 311 who were assessed for TPT eligibility, 126 (41%) started TPT and 119 were assessed for TPT outcomes. Of these, 111 (93%) had successful TPT outcomes. The median times to starting TB treatment and TPT were 7 days and 11 days, respectively. The intervention facilitated timely access to healthcare services and a high yield of TB detection.
Tropical Medicine and Infectious Disease · 2025-10-18
articleOpen accessTuberculosis preventive treatment (TPT) reduces the incidence of tuberculosis (TB) among people living with HIV (PLHIV), but its coverage remains suboptimal in most settings. We conducted a cross-sectional study to describe TPT uptake among PLHIV and factors influencing TPT initiation. Healthcare workers (HCWs) in selected facilities were trained and supported to strengthen TPT management among PLHIV, including children living with HIV (CLHIV). Of 1309 enrolled PLHIV, 1268 (97%) were eligible for TPT; 1078 (85%) initiated TPT, including 663/776 (86%) among those currently on ART and 415/492 (84%) among clients newly on ART. The major reasons for not starting TPT included stock-outs of TPT medicines, TB disease, and refusal of TPT, mostly by CLHIV and adults currently on ART. Optimal and sustained uptake of TPT can be achieved through ensuring uninterrupted stocks of TPT medicines, including shorter regimens and pediatric formulations, addressing knowledge deficits among HCWs, and improving demand for TPT by educating PLHIV and caregivers of CLHIV about the benefits and risks of TPT formulations.
MMWR Morbidity and Mortality Weekly Report · 2025-03-20 · 2 citations
articleOpen accessSenior authorTo help achieve the End TB Strategy target of a 90% reduction in tuberculosis (TB) incidence by 2030, member states of the United Nations High-Level Meetings on TB called for improving provision of TB preventive treatment (TPT) for household contacts of persons with TB, who are at increased risk for infection and disease. However, TPT use among household contacts worldwide remained at 21% in 2023. The International Union Against Tuberculosis and Lung Disease, the Uganda Ministry of Health, and CDC piloted a comprehensive approach for increasing case finding and TPT coverage among household contacts of persons with TB. During November 1, 2023-September 30, 2024, a total of 521 index patients with TB disease were registered at six health facilities in Uganda. Home visits to index patients identified 1,913 household contacts, 1,739 (91.0%) of whom underwent TB symptom screening at home; 321 (18.5%) reported TB symptoms. Of 309 (96.3%) persons with TB symptoms who were further evaluated, 284 (91.9%) provided a sputum specimen for laboratory testing, including 270 (84.1% of those with symptoms) who did so during the home visit; 214 (69.3%) underwent chest radiography. Overall, 80 TB cases were diagnosed; in 61 (76.3%) persons, the diagnosis was based on radiographic findings. Among 1,496 HHCs eligible for TPT, 1,239 (82.8%) initiated treatment and 1,178 (95.1%) completed it. Global scale-up of this approach might help reach global TB elimination goals.
European Journal of Cancer · 2024-10-01 · 1 citations
articleMMWR Morbidity and Mortality Weekly Report · 2024-03-21 · 6 citations
articleOpen accessTuberculosis (TB) is the leading cause of death among persons with HIV. In 2022, an estimated 167,000 TB-related deaths occurred globally among persons with HIV. TB preventive treatment (TPT) helps prevent TB disease and is recommended for persons at high risk for developing TB, including those with HIV. TPT, when taken with antiretroviral treatment (ART), can reduce TB-attributable deaths among persons with HIV. In 2018, the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) program committed to offer one course of TPT to all eligible clients receiving ART. This analysis describes trends in TPT initiation and completion among PEPFAR-supported programs in 36 countries in Africa, Central and South America, and Asia during fiscal years (FYs) 2017-2023. Overall, TPT initiation rates peaked in FY19, a possible sign of programmatic saturation. TPT initiation among clients who had been on ART <6 months reached 59%, and overall completion rates up to 87% were reported. Approximately 13 million persons with HIV have completed TPT since FY17, but widespread adoption of shorter regimens, patient-centered approaches, and electronic medical record systems might be needed to ensure full TPT coverage. Through PEPFAR's partnership with national HIV programs, TPT has become the standard of care for persons with HIV.
Recent grants
NIH · $181k
NIH · $654k · 2013
Frequent coauthors
- 92 shared
Jean W. Pape
Weill Cornell Medicine
- 66 shared
Linnie M. Golightly
Weill Cornell Medicine
- 65 shared
Glavdia G. Delva
Massachusetts Institute of Technology
- 64 shared
Rachel F. Daniels
University of Massachusetts Chan Medical School
- 64 shared
Sanchita Das
National Institutes of Health Clinical Center
- 64 shared
Leopoldo Villegas
- 64 shared
Sarah K. Volkman
Simmons University
- 64 shared
Laura A. Kirkman
Weill Cornell Medicine
Labs
Education
B.S., Chemical and Biomolecular Engineering (CBE)
Cornell University
M.S., Chemical and Biomolecular Engineering (CBE)
The Ohio State University
Ph.D., Chemical and Biomolecular Engineering (CBE)
The Ohio State University
Awards & honors
- Cornell Provost’s New Faculty Fellow
- Faculty Fellow of the Cornell Atkinson Center for Sustainabi…
- Resume-aware match score
- Save to shortlist
- AI-drafted outreach
See your match with Michael Charles
PhdFit ranks faculty by your research interests, methods, and publications — grounded in their actual work, not templates.
- Free to start
- No credit card
- 30-second signup