Digital Commons Network^™

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 …

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, …

The Role Of Climate Change In The Pandemic Agreement Negotiations, Cristina Arnes Sanz

Public Health Theses

Introduction: For over three years, Member States of the World Health Organization (WHO) have been negotiating a treaty to prevent, prepare for, and respond to future pandemics. The Pandemic Agreement is anticipated to be adopted at the World Health Assembly in May 2025. Growing scientific evidence underscores the effects of climate change on infectious diseases, including those that could lead to pandemics. This thesis examines how climate change has been addressed in the drafting and negotiations of the Pandemic Agreement.

Methods: All the references related to climate change in the transcripts of the publicly broadcast Intergovernmental Negotiating Body (INB) meetings …

Modeling Impacts Of Water Improvements On Typhoid In Urban South Asia, Chessley Blacklock-Votava

Public Health Theses

Introduction: Typhoid fever represents a significant burden of disease in urban areas across South Asia. While the recent implementation of routine typhoid conjugate vaccinations (TCVs) has demonstrated significant protective effectiveness against disease, it fails to mitigate environmental transmission through contaminated water, which individuals without access to improved water sources (IWS) may be infected by. Objectives: The primary aim of this study is to estimate the potential reductions to typhoid fever incidence that populations could experience when increasing proportions of the population that have IWS across three high-burden cities in South Asia. The relationship between this reduction and the proportion of …

Evaluating Saliva Based Glucose Testing For Accessible Diabetes Care In Tanzania, Shannon Dhindsa

Public Health Theses

Background: In Tanzania, limited healthcare infrastructure and reliance on invasive diagnostic methods significantly hinder effective diabetes screening and management. Individuals with diabetes often go undetected and have lower immune systems that make them prone to further infectious complications. Thus, properly managing this chronic condition can prevent additional infectious diseases. Salivary glucose testing offers a non-invasive, innovative alternative with the potential to transform the early detection and management of diabetes, especially in resource-constrained settings.

Design: This cross-sectional study, conducted at Muhimbili National Hospital's Diabetes Clinic in Dar es Salaam, evaluates the feasibility of salivary glucose testing using a colorimetric glucose-oxidase-peroxidase point-of-care …

A Commitment To Health For All: Reimagining Representation And Participation In The Who Beyond State-Centrism, Yen-Wen Liao

Public Health Theses

Despite its stated commitment to “health for all,” the World Health Organization (WHO) has long been subject to the influence of Member State politics. Specifically, the Organization’s state-based membership model and governance structure have continuously enabled powerful Member States to advance their political interests, leading to the exclusion and marginalization of populations based on the recognition or political status of their representatives. One such example is Taiwan, which has been repeatedly denied membership in the Organization despite the functional independence of its public health authority, leaving over 23 million people neglected amid two major health crises. These forms of exclusion …

Antibiotic-Resistant Nontyphoidal Salmonella And Campylobacter Isolates Associated With International Travel, Connecticut 2010 – 2023, Shilpa Mudumbe

Public Health Theses

Antibiotics are helpful for limiting duration and complications of Salmonella andCampylobacter isolates in selected age groups and people who are immunosuppressed. However, antibiotic-resistant (AR) foodborne pathogens have been on the rise in the United States over the past 10 years and are often linked to international travel (IT). Long-term trends on AR have not been examined in Connecticut (CT). This study evaluates trends in AR among nontyphoidal Salmonella and Campylobacter isolates in CT from 2010 to 2023 and examines the association between AR and IT. Data from submission of annual systematic samples of CT Salmonella and Campylobacter isolates to the …

Enhancing Dengue Forecasting With Remotely Sensing-Derived Vector Proxies And Random Forest Models: A Case Study For Sri Lanka, Shuyu Ye

Public Health Theses

Dengue fever is a growing global public health threat, especially in tropical and subtropical regions such as Sri Lanka, where seasonal outbreaks impose recurring burdens on health systems. Accurate and timely forecasting of dengue incidence is essential for public health preparedness, yet most existing models suffer from key limitations: they rely on historical case trends without accounting for real-time ecological dynamics, and often require entomological surveillance data that is not consistently available. This thesis addresses these gaps by proposing a machine learning forecasting framework that integrates remote sensing-derived environmental proxies to estimate latent mosquito vector abundance.Using Principal Component Analysis (PCA), …

Economic Burden Of Medically Attended Respiratory Syncytial Virus Illness Among Older Adults, Shirley Zhu

Public Health Theses

ABSTRACTIntroduction: Respiratory syncytial virus (RSV) is a common respiratory pathogen that causes a large burden of disease among older adults. Though there are interventions, the impact and cost-effectiveness of recently licensed RSV vaccines in the United States is not well understood for this population. Thus, reliable estimates on the economic burden of RSV among older adults are needed for future economic analyses.

Objective: The objective of this thesis is to evaluate the cost of medically attended RSV among older adults in the United States.

Methods: Medicare claims data were used to determine average cost per visit for outpatient, inpatient, emergency …

Enhancing Research Utilization Among Health Policymakers: Lessons From An Executive Certificate Program In Liberia, Felicia Annan-Mills

Public Health Theses

Evidence-based decision-making in health policy is a systematic and transparent approach to policymaking and program design using research evidence and other similar sources. It is essential for developing effective health policies and ensuring that programs align with political priorities and community needs and have strong empirical support for their efficacy and impact. Global health agencies like the World Health Organization and the West African Health Organization have developed guidelines for evidence-based decision-making in health for organizations to use as guiding tools in their policymaking. Regardless, there is still a gap in applying research evidence to practice programs for many countries …

Cost-Effectiveness Of New Monoclonal Antibody And Maternal Immunization For The Prevention Of Respiratory Syncytial Virus (Rsv) Disease In Infants: A Systematic Review, Yuwei Che

Public Health Theses

AbstractIntroduction: Respiratory syncytial virus (RSV) remains a major cause of morbidity and mortality among infants and young children worldwide. Given the lack of specific therapeutic treatments for RSV that are suitable for universal use, the development of effective prevention strategies is of paramount importance. Previously, palivizumab was utilized for long-term prophylaxis of RSV infections; however, it was only recommended for specific populations due to its high cost and limited overall effectiveness. In 2023, the U.S. FDA approved RSVpreF maternal vaccine (Abrysvo™, Pfizer), and nirsevimab (Beyfortus™, Sanofi and AstraZeneca) for the prevention of RSV to newborns. Two newly developed interventions have …