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Global Health Financing Of Diagonal Interventions: Building Resilient And Sustainable Health Systems In Sub-Saharan Africa, Lucy Kim

Master in Public Policy Theses

Background: Global health financing has historically prioritized disease-specific “vertical” programs over broader “horizontal” strengthening of general health systems. Vertical programs in HIV have led to unprecedented reductions in mortality worldwide, but HIV remains a significant public health threat in sub-Saharan Africa, where vertical strategies have long been criticized for creating fragmented health systems. In response, global health strategies have shifted towards combining vertical investments with broader horizontal activities, commonly referred to as “diagonal” programming. While evidence suggests that diagonal programming has the potential to create more resilient and sustainable health systems, evaluating its value for money is challenging due to …

Methylenetetrahydrofolate Reductase (Mthfr) Polymorphisms And Neural Tube Defects In African Populations: A Global Meta-Analysis And Population Genetic Characterization In Uganda, Nana Ekua Entsiwa Adenu-Mensah

Yale Medicine Thesis Digital Library

Background: Neural tube defects (NTDs) affect 1.9 per 1,000 births globally, with the highest burden occurring in African populations that remain underrepresented in genetic epidemiology. The methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms reduce enzyme activity and have been associated with increased NTD risk in several populations, though their relevance across African regions remains unclear.

Methods: We conducted: (1) an updated systematic review and meta-analysis of MTHFR C677T and A1298C polymorphisms and NTD risk (66 studies, ~22,000 participants); (2) population-level genotype characterization of 978 Ugandan children using whole-genome sequencing; and (3), a comparative analysis of MTHFR C677T allele frequencies across …

A Questionnaire Assessing Attitudes And Readiness For Hiv Pre-Exposure Prophylaxis Therapy For Community Members At-Risk For Hiv Acquisition In Liberia, Yishak Bedaso

Yale Medicine Thesis Digital Library

AbstractA Questionnaire Assessing Attitudes And Readiness For HIV Pre-Exposure Prophylaxis Therapy For Community Members At-Risk For HIV Acquisition In Liberia Yishak Bedaso;1 Jessica Tuan, MD, MS;2 Yassah M. Barclay-Korboi;3 Onyema Ogbuagu MBBCh, FACP, FIDSA4 Affiliation: 1. Yale School of Medicine, New Haven, CT, USA 2. Columbia University Vagelos College of Physicians and Surgeons, Department of Infectious Diseases, New York, NY, USA 3. JFK Memorial Hospital, Monrovia, Liberia. 4.Yale Antivirals & Vaccines Research Program, Section of Infectious Diseases, Yale School of Medicine, New Haven, CT, USA; Despite how effective Pre-exposure prophylaxis (PrEP) is in preventing HIV, uptake among women in sub-Saharan …

A Machine Learning Tool For Predicting End-Stage Renal Disease Within One-Year Of Heart Transplantation, Cole Tetsuo Cassady

Yale Medicine Thesis Digital Library

End-stage renal disease (ESRD) after heart transplantation is a common complicationwhich increases risk of mortality. Simultaneous heart-kidney transplantation (SHKT) lowers this risk. Eligibility for SHKT relies on pre-transplant estimated glomerular filtration rate (eGFR) with ongoing discussion regarding optimal eligibility guidelines. We present an eXtreme Gradient Boosting Decision Tree (XGBoost) machine learning model for predicting ESRD within one year of heart transplant procedure in candidates ineligible for kidney-alone transplantation. The model was trained using readily available elements from pre-transplant evaluation and performed with an area under the receiver operating characteristic curve (AUROC) of 0.71. The model discrimination was statistically significantly better …

Prevalence Of K13 Mutant Malaria Parasites In Busia, Uganda, Ahmed Elzamzami

Yale Medicine Thesis Digital Library

Artemisinin derivatives form the backbone of all antimalarial combination therapies usedworld-wide. Resistance to this critical drug class is a growing problem in the highest malaria transmission regions of the world. First detected in southeast Asia, independent mutations conferring partial resistance to artemisinin’s have now emerged in East Africa.27, 32 Retrospectively, these mutations have been detected as early as 2016 in Uganda.36 Previous work by the Parikh lab highlights the efficacy of 3-day vs 5-day artemether-lumefantrine treatment regimen for uncomplicated malarial episodes in Busia, Uganda in 2019.41 Infections were followed and classified as recrudescent, a reinfection, SBP1 slow clearing, or an …

Tone Matters: Advancing Equity Through A Pilot Intervention To Increase Exposure Of Clinical Findings In Skin Of Color, Lamley Amanuah Lawson

Yale Medicine Thesis Digital Library

Background: The ability to accurately recognize cutaneous manifestations of disease is a foundational clinical skill. However, current undergraduate medical education heavily relies on lighter skin tone prototypes, leaving trainees underprepared to diagnose conditions in patients with melanin-rich skin.Research Aims: This study aimed to evaluate the efficacy of a brief, targeted, visually comparative digital intervention by measuring its impact on medical students' immediate diagnostic accuracy and self-reported clinical confidence in identifying dermatologic conditions across a diverse range of skin tones. Hypothesis: We hypothesized that a brief, targeted digital educational intervention featuring side-by-side visual comparisons of dermatologic conditions across a range of …

Implementing Hepatitis C Screening And Treatment In Primary Care, Michele Castellano Wetmore

Yale School of Nursing Digital Theses

AbstractHepatitis C (HCV) is a curable hepatic disease. With direct-acting antivirals, it can be treated in 95% of cases. When left untreated, it can cause severe liver disease, including hepatocellular carcinoma and even death. The World Health Organization’s (WHO) goal is to eliminate HCV by 2030. This Quality Improvement (QI) project, conducted at a Federally Qualified Health Center (FQHC) from 8/4/2025 to 11/4/2025, will address the barriers to elimination and show that providing local services closes gaps. Screening and treating HCV within primary care has become a strategic approach to enhance access to treatment. This involves developing and utilizing a …

Predicting Healthcare-Seeking For Childhood Diarrhea Across Low- And Middle-Income Countries, Madi Baltagulov

Public Health Theses

Healthcare-seeking behavior (HSB) for childhood diarrhea is a central but persistently uncertain input for rotavirus burden models and vaccine cost-effectiveness analyses. Demographic and Health Surveys (DHS) provide the only nationally representative measurements, yet they are expensive and absent from the majority of low- and middle-income countries (LMICs). This thesis asks whether publicly available country-level indicators can substitute for DHS data when survey estimates are unavailable.Using the most recent DHS conducted between 2011 and 2024 in 51 LMICs (78,008 children under five with diarrhea), I fit a multilevel modified Poisson regression and a two-stage random-effects meta-regression with four World Bank moderators: …

Stigma, Coping & Resilience Among Hiv+ Pwid In St. Petersburg, Rf, Gabrielle Bogut

Public Health Theses

Russia and the other countries that comprised the Soviet Union constitute the one region in which the HIV epidemic continues to expand. Unlike most other regions, more than a quarter of HIV cases in Russia resulted from unsafe injection among people who inject drugs (PWID), and St. Petersburg is among the cities with the highest rates and case counts of HIV. Our study sought to identify actionable psychosocial characteristics influencing receipt of antiretroviral therapy (ART) in PWID. This study assessed survey results from 225 HIV-positive individuals recruited from a Russian NGO that provides PWID with harm reduction services. Individuals were …

Scaling Up Long-Acting Hiv Prep: Perspectives From Health Practitioners On Implementation Of Twice Yearly Lenacapavir, Taylor Braunstein

Public Health Theses

BackgroundLenacapavir (LEN), a twice-yearly subcutaneous injectable Pre-Exposure Prophylaxis (PrEP) medication for HIV, was approved by the Food and Drug Administration (FDA) in 2025. LEN represents a significant advancement in HIV prevention, demonstrating 99.96-100% efficacy in the PURPOSE 1 and 2 clinical trials12,21. Despite its promise in HIV prevention, high list prices, complex loading regimens, and implementation uncertainties pose barriers to widespread uptake. This study examines provider perspectives on the acceptability, feasibility, and appropriateness of LEN as PrEP, as well as perceived implementation barriers and facilitators. Methods This mixed-methods, cross-sectional study recruited licensed US practitioners (RNs, NPs, PAs, MDs, DOs, and …

Clostridioides Difficile Infection Trends And Treatment Concordance With Idsa/Shea Guidelines In The Connecticut Emerging Infections Program Catchment Area, 2011-2024, Rachael Hopkins

Public Health Theses

Background: Clostridioides difficile infection (CDI) is a gastrointestinal infection causing colon inflammation, diarrhea, and potential life-threatening complications. In 2021, treatment guidelines for CDI were updated by the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA). This study analyzed Connecticut Emerging Infections Program (EIP) data to assess CDI incidence trends (2011-2024) and evaluate physician concordance with 2021 guidelines for incident cases (2022-2024). Methods: The Connecticut EIP conducted CDI surveillance in New Haven County (2011-2023) and South Central and Naugatuck planning regions (2024). Incidence rates were calculated using census data. Concordance was defined as treatment …

Cost-Effectiveness Analysis Of Twice-Yearly Injectable Lenacapavir Versus Daily Oral Prep For Hiv Prevention Among Men Who Have Sex With Men In China, Xueqing Guo

Public Health Theses

Men who have sex with men (MSM) remain a key at-risk population in China’s HIV epidemic while the real-world effectiveness of daily oral pre-exposure prophylaxis (PrEP) among MSM has been limited by low uptake and suboptimal drug adherence. Lenacapavir, a first-in-class capsid inhibitor administered twice yearly, emerged as a highly efficacious, long-acting prevention strategy with the potential to reduce drug burdens associated with current PrEP strategy. However, its high price ($28,000 per patient per year) raises major affordability concerns, and its economic value in China remains understudied. This study aimed to evaluate the cost-effectiveness of lenacapavir compared with daily oral …

Using The Behavior Change Wheel To Understand The Role Of Antimicrobial Stewardship Programs, Siqi Jiang

Public Health Theses

Objectives: This review aimed to summarize recent antimicrobial stewardship programs (ASPs) implemented in pediatric outpatient settings and analyze how these interventions influence appropriate antibiotic use.Methods: PubMed and Scopus were searched for studies published between 2016 and 2026 globally. Studies were included if they evaluated an antimicrobial stewardship intervention in a pediatric outpatient setting. Only English studies are included. Studies that describe the results of implementations and policies related to ASP are included, including randomized controlled trials, quasi-experiments, natural experiments, quality improvement studies and observational studies, and longitudinal studies. Interventions in selected articles were analyzed using the COM-B (Capability, Opportunity, Motivation-Behavior) …

Kinetics Of Antibody Responses To Hookworm Excretory/Secretory Products In A Hamster Model Of Infection And Cure, Jacquelyn Kauffman

Public Health Theses

Hookworms are a major global health burden in resource-limited settings despite ongoing control programs. This makes understanding host immune responses to infection and treatment critical to improve diagnostics and interventions. This study investigates the long-term kinetics of antibody responses following infection with Ancylostoma ceylanicum in a hamster model. Over a one-year study, groups of six hamsters were assigned to uninfected, infected, or infected then treated groups, with antibody responses measured using ELISAs. All infected animals had elevated IgG, IgM, and IgA responses by day 21 post infection. Mebendazole-treated hamsters had significantly reduced, but not eliminated, antibody levels, with IgM responses …

Nowcasting Dengue Cases In Poor Surveillance Nations Using Meteorology And Climate-Similar Countries, Hanna Kim

Public Health Theses

Dengue fever poses a growing public health burden across the Caribbean, yet surveillance infrastructure remains inconsistent and timely outbreak detection in data-poor nations becomes limited. This study investigates whether shared meteorological patterns between Caribbean countries can be leveraged to nowcast dengue activity in low-surveillance settings using climate-matched, well-surveilled nations as epidemiological proxies. Weekly and monthly dengue case data for six countries, the Dominican Republic, Jamaica, Puerto Rico, Trinidad and Tobago, Cuba, and Haiti, were extracted from the OpenDengue database for 2005–2024, and satellite-derived climate data were obtained from the NASA POWER API. Pairwise climate correlations revealed strong temperature synchrony across …

Pediatric Rheumatic Heart Disease Screening For Secondary Antibiotic Prophylaxis: An Explainable Shannon Energy Approach Using Heart Phonocardiogram In Northeast Brazil, Zhuohui Lin

Public Health Theses

Rheumatic Heart Disease (RHD), caused by Group A Streptococcus (GAS), remains a significant global health burden, particularly among children in low- and middle-income countries. Untreated GAS infection can lead to acute rheumatic fever and subsequent chronic valvular damage of RHD, such as mitral valve (MV) regurgitation. Hence, early detection is critical for the administration of Secondary Antibiotic Prophylaxis to prevent disease progression. Although deep learning models demonstrate high diagnostic accuracy, limited explainability restricts clinical adoption, especially in resource-limited settings. In this proof-of-concept study, we evaluated Shannon energy (SE) transformation as a proxy to differentiate holosystolic murmurs associated with RHD-related mitral …

Climate, Land Use, And Lyme Disease Risk In The United States, Mohan Li

Public Health Theses

Lyme disease is the most common vector-borne bacterial infection in the United States. It remains an important public health concern due to its high disease burden, expanding geographic distribution, and complex transmission cycle. Climate change is frequently regarded as a driver of Lyme disease emergence, as many previous studies suggested. However, ongoing debate about the magnitude and mechanisms of climate effects complicates the interpretation of this relationship. This review synthesizes evidence on how climate influences Lyme disease through both direct and indirect pathways, with a focus on studies relevant to the United States and North America.Climate directly affects Lyme disease …

Characterization Of Tick Exoproteins Interacting With Anaplasma Phagocytophilum, Yilei Qin

Public Health Theses

Anaplasma phagocytophilum (Ap) is an Ixodes-transmitted obligate intracellular bacterium thatinfects neutrophils and causes human granulocytic anaplasmosis. Ap alternates between an infectious dense-cored (DC) form and a replicative reticulate cell (RC) form, and successful transmission depends on coordinated interactions at the vector–pathogen interface. Tick extracellular and secreted proteins (the tick exoproteome) likely contribute to Ap survival and transmission, yet many proposed tick factors remain computationally annotated with limited experimental validation. In this thesis, I prioritize candidate tick exoproteins, identified from yeast- display screens using whole Ap organisms, and evaluate them using a two-step validation strategy. First, I quantify tissue-specific expression of …

Invasive Pneumococcal Disease: Outcomes And Vaccine Effectiveness By Risk Profiles Among A Pediatric Cohort From 2002 – 2025, Keyner Rojas

Public Health Theses

AbstractBackground: Invasive pneumococcal disease (IPD) remains a significant cause of morbidity and mortality among children globally, despite the widespread use of protein conjugate vaccines (PCVs). While the introduction and implementation of these vaccines have drastically reduced the incidence of vaccine-type invasive disease, shifts in circulating serotypes raise concerns of serotype replacement. Methods: This study is a retrospective observational study of pediatric IPD cases in Massachusetts from 2002 – 2025. Over the course of these 23 years, the Massachusetts Department of Public Health has operated an enhanced population-based, statewide surveillance system for IPD. Isolates of Streptococcus pneumoniae from normally sterile sites …

Vibriosis In Connecticut: Case Trends And Seasonality, 1997–2024, Lisa Michelle Stutzman

Public Health Theses

Vibrio bacteria species, including V. vulnificus and V. parahaemolyticus, cause vibriosis, which can present as gastrointestinal illnesses, wound infections, or septicemia. In the United States the geographical range of these infections is growing, with the northward expansion of Vibrio along the Atlantic coast highlights the importance of understanding trends in vibriosis in Connecticut. This analysis is based on surveillance data from the Connecticut Emerging Infections Program from January 1, 1997–December 31, 2024. Analyses were restricted to culture-confirmed cases to ensure consistent case definitions and conducted on data aggregated to the state level. Descriptive statistics were used to characterize trends in …

Effectiveness Of The Release Of Wmel Wolbachia-Infected Aedes Aegypti Mosquitoes On The Incidence Of Chikungunya In Campo Grande, Brazil, Vivienne Zhong Ying Su

Public Health Theses

Chikungunya is a mosquito-borne arboviral disease primarily transmitted by Aedes aegypti and Aedes albopictus that is rapidly emerging in new geographical settings because of climate change, viral adaptation, and globalization. Brazil has experienced the significant expansion of chikungunya over the past decade and has adopted novel vector control interventions, including Wolbachia-based population replacement, as part of its public health response. While the effectiveness of wMel Wolbachia on dengue incidence has been demonstrated across multiple settings, evidence on its effect on chikungunya risk remains limited. Large-scale releases of wMel-infected Aedes aegypti mosquitoes were implemented in the city of Campo Grande, Brazil …

Redefining Hospital-Acquired Rsv: Epidemiologic Burden And Probabilistic Classification In A Large Health System, Anna Trinh

Public Health Theses

Healthcare acquired respiratory syncytial virus (HA RSV) is an important but under recognized infection in adult patients. Current surveillance definitions classify RSV as healthcare acquired when a positive test occurs ≥48–72 hours after admission, despite a broad incubation period of 2–8 days which would allow community acquired infections to present several days into hospitalization. This thesis has two aims: (1) to describe the epidemiology of adult HA RSV cases in the Yale New Haven Health System (YNHHS) from 2021–2025, and (2) to develop an incubation period-based probabilistic model to assess the plausibility of each HA RSV classification. Among 2,905 laboratory-confirmed …

Influenza-Associated Hospitalizations And Socioeconomic Status In Southern Connecticut, 2022-2025, Allison Traiger

Public Health Theses

Background: Influenza is a common respiratory illness in the United States responsible for hundreds of thousands of influenza-associated hospitalizations each year. To implement effective preventative interventions, it is crucial to understand which populations are most at risk of severe illness and hospitalization. Prior studies have found that increased rates of poverty and crowding are associated with increased rates of hospitalization.Methods: This study explores the connection between neighborhood poverty, crowding, and influenza-associated hospitalization through the connection of hospitalized influenza cases with their census tract-level socioeconomic indicators. Addresses of hospitalized cases were geocoded and linked to data on poverty and crowding from …

Asymptomatic Tb Duration And Transmission Models, Zhichao Zhou

Public Health Theses

Tuberculosis (TB) transmission is sustained in part by asymptomatic disease states that limit the effectiveness of passive case finding interventions that rely on symptom-based diagnosis. Here we develop a transmission model that represents the duration of asymptomatic disease with a gamma-distributed waiting time. By chaining multiple asymptomatic sub-states, we find that the gamma-distributed model provides a better fit to the observed distribution of the duration of asymptomatic disease than a simple one-state model which imposes an assumption of an exponentially-distributed duration of asymptomatic disease. Comparing the fitted gamma-distributed model and the simple model, we quantify how assumptions about the distribution …

Mass Sars-Cov-2 In A State Correctional System During The Pandemic, Charlotte Kim

Yale Medicine Thesis Digital Library

Mass screening has been shown to be more efficient in identifying infections in correctional facilities compared to symptom-based screening, but little is known about the impact of systematic mass screening on timely isolation of infectious cases over the course of the entire pandemic. Between March 2020 and May 2023, the Connecticut Department of Correction (CT DOC) performed a multifaceted SARS-CoV-2 testing strategy for its incarcerated population, which included RT-PCR for mass screening, as well as rapid antigen testing for contact tracing, symptom-based screening, and other miscellaneous reasons. Testing data reveals that mass screening identified 48% of all positive results, whereas …

Pancreatic Cancer Risk After Chronic Hepatitis C Virus Infection: A National, Population-Based Study, Rachel Levinson

Yale Medicine Thesis Digital Library

Studies of the association of hepatitis C virus (HCV), a known oncovirus, and pancreatic ductal adenocarcinoma (PDAC) are limited. We aimed to assess the relationship between chronic HCV infection, HCV genotype, and PDAC. In this retrospective cohort study, we identified individuals in the Veterans Health Administration from 2001 to 2021 with HCV testing. We categorized HCV status as those without HCV, those exposed (without chronic infection), or those with chronic infection. We evaluated incident PDAC by HCV status using Cox proportional hazards regression, adjusting for pertinent confounders. We further investigated the association between HCV genotype and risk of PDAC. Of …

Long Covid And Vulnerability To Climate Change’S Health Effects: An Informational Booklet For Healthcare Settings, Rachel Nussbaum

Public Health Theses

According to the World Health Organization, around 10–20% of people infected by COVID-19 may go on to develop symptoms that can be diagnosed as Long COVID, also known as the post-acute sequelae of COVID-19 (PASC). While the risk of Long Covid among people who received the primary vaccine series fell to 3.5% in one study, as of September 2024, over 1.3 million Americans were being infected with SARS-CoV-2 every day, and reinfections increase the likelihood of experiencing Long Covid in some studies. Continued transmission of SARS-CoV-2 has led to roughly 400 million people experiencing infection-associated chronic conditions, creating an accumulating …

Enhancing Disease Surveillance In Conflict Settings: An Ecological Case Study On Cholera In Sudan At The Intersection Of Environmental And Conflict Drivers, Kinsey Medlin

Public Health Theses

Cholera outbreaks are complex and driven by an interaction of environmental circumstances and conflict-related disruptions, yet few studies have integrated both in the context of conflict regions. This ecological study examines cholera transmission dynamics in Sudan from 2016 to 2025, exploring temporal associations using cross-correlation analysis and applying generalized additive mixed models (GAMMs) to analyze the influence of remotely sensed environmental variables (rainfall, temperature, NDVI, NDWI) and conflict indicators (civilian targeting, political violence, demonstrations) on cholera cases. Weekly cholera surveillance data, combined with satellite-derived environmental variables and conflict event datasets, were modeled across two time periods: pre-conflict (2016-2018) and active …

Cross-Sectional Study On The Distribution And Epidemiology Of Plasmodium Ovale Species In Asymptomatic And Symptomatic Individuals In Gulu, Uganda, Xiaohan Xu

Public Health Theses

Despite global progress in malaria control, Plasmodium ovale remains an under-recognized contributor tothe malaria burden in sub-Saharan Africa. Its ability to form dormant liver-stage hypnozoites enables silent, recurrent transmission that often escapes detection by routine diagnostics. This cross-sectional study investigated the prevalence, species distribution, and clinical profile of P . ovale infections in Gulu, Uganda, comparing asymptomatic individuals from the community to symptomatic patients presenting at Gulu Regional Referral Hospital. Molecular diagnostics, including qPCR, nested PCR, and hemi-nested PCR, were used to detect and differentiate P . ovale curtisi and P . ovale wallikeri. Geographic sampling was conducted across 33 …

Risk Factors Of Respiratory Syncytial Virus (Rsv) Infection In Infants: A Study Using New York State Inpatient And Outpatient Databases, Mengjing Yang

Public Health Theses

Respiratory syncytial virus (RSV) infection is the main cause of respiratory diseases in infants, but the sociodemographic differences in RSV risk have not been fully understood for New York State infants within the first two years of life. This study aims to investigate the distribution and risk factors of respiratory syncytial virus infection in infants and young children under 2 years old in New York State.We conducted a retrospective cohort study using the data from the New York State Inpatient Database (SID) and the State Emergency Department Database (SEDD) from 2016 to 2019. Analyze sociodemographic characteristics, including birth weight, gender, …