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: …

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 …

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 …

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), …

Prevalence And Correlates Of Antipsychotic Use Without An Indicated Diagnosis Among Long-Stay Residents In Nursing Facilities In Massachusetts, Hongyi (Sophie) Liu

Public Health Theses

Background: In 2012, the Centers for Medicare & Medicaid Services (CMS) implemented initiatives to reduce unnecessary antipsychotic medication use in elderly nursing home residents to ensure quality of care. While antipsychotic use among long-stay nursing home residents has decreased nationwide, Massachusetts still exceeds the national average and ranks 6th in the U.S. This study aims to evaluate and identify both facility-level characteristics and resident-level correlates of antipsychotic use without an indicated diagnosis among long-stay residents in Massachusetts nursing homes. Methods: The study examined 30,857 long-stay residents across 345 nursing facilities in CY2023, using data from the Minimum Data Set (MDS), …

Under-Five Malaria And Malnutrition Syndemic In Rajasthan, Nandini Sinha

Public Health Theses

Background: The syndemic of severe acute malnutrition (SAM) and malaria in under-five children in Rajasthan presents a critical public health challenge. Current SAM and malaria programs are implemented as siloed interventions despite the potential benefits of integrated approaches. A better understanding of the interactions between these factors is important to strengthen the delivery of integrated services.

Objective: This study investigates the relationship between under-five SAM and malaria infections at the block level in Rajasthan to inform targeted, integrated interventions. By running regression analysis, we will identify associations between these co-occurring health threats to guide state-level policy integration. To the best …

Identifying The Multilevel Factors Influencing Provider Recommendations For Adolescent Vaccines, Mallory Kathryn Ellingson

Yale Graduate School of Arts and Sciences Dissertations

Health care provider (HCP) recommendations are a key predictor of vaccineacceptance among parents of adolescents. However, HCP recommendations for adolescent vaccines are not universal. In order to address disparities in HCP recommendations, we must first understand why recommendations vary. The factors that influence a HCP recommendation are multilevel. At the individual level, a HCP’s own knowledge, attitudes and beliefs about a vaccine can influence how or if they recommend the vaccine to a patient. At the interpersonal level, the characteristics of the patient can impact how a HCP perceives disease risk or need for a vaccine in their patient. At …

Light At Night And Cancer Incidence: A Gis-Based Study In The Us, Linshuoshuo Lyu

Public Health Theses

Aims: Light at night (LAN) can cause circadian disruption and was found to be a potential risk factor for several cancers. This study aims to confirm the adverse effect of LAN on hormone-related cancers and explore the association between LAN and the prevalence of various cancer types under an ecological study design. Methods: County-level age-adjusted cancer incidence data was obtained from the CDC Cancer Statistics (2016 to 2020), while LAN data (1996 to 2000) was obtained from the satellite imagery of Version 4 Defense Meteorological Satellite Program. Linear mixed effect regression models (LMMs) were performed to assess the relationship of …

Do Rental Assistance Programs Relieve Overcrowding In U.S. Children?, Frank Zhu

Public Health Theses

Introduction: Crowded living conditions are associated with many negative health outcomes, with significant implications for children, as they are particularly shaped by their home environment and more likely to live in crowded conditions, given their larger household size. How rental assistance programs may shape and improve household crowding has not been previously explored. Methods: This study leveraged data from NHANES linked with HUD administrative rental assistance records. We examined changes in crowding measures in U.S. children using linear and logistic regression models stratified by different rental assistance program types. Results: There was a statistically significant 40 percentage point reduction in …

Association Of Diurnal Temperature Range With Pediatric Influenza Hospitalization Rates In The United States, 2009 – 2019, Khang Duy Tran

Public Health Theses

Introduction: Climate change may have a negative impact on respiratory illnesses, such as influenza. Diurnal temperature range (DTR), an indicator of climate change, is the difference between the maximum and minimum temperature within a day or a week. As the climate warms, global DTR decreases, though there might be regions where DTR increases instead. Previous literature conducted in non-U.S. regions found both positive and negative associations between DTR and influenza infections. A group especially vulnerable to the effects of DTR are children less than 5 years of age due to their less-developed thermoregulation capability. This study thus aimed to explore …

“Am I Sick Or Just Discarded?”: Psychiatry, Health Care Reform, And The Rise Of Geriatrics In America, 1931-1954, Sophie E. Edelstein

Harvey M. Applebaum ’59 Award

Between 1931 and 1941, the United States population over the age of sixty-five increased by over 35 percent. These individuals, however, did not receive increased support. Rather, American politicians and society at large labeled the elderly a ‘burden,’ and passed off their care to the overworked medical personnel of state and federal mental institutions. Sparked by clinical exposure to the influx of elderly patients to mental institutions, Massachusetts psychiatrist David Rothschild identified an erroneous assumption in care practices for senile patients. In many cases, physicians preemptively diagnosed those admitted to state and federal institutions with some form of senile dementia, …

The Potential Link Between Pfas And Colorectal Cancer: A Narrative Review, Amina Mutalib

Public Health Theses

Background: Currently, there is information on the detrimental impacts of exposure to pollutants such as per- and polyfluoroalkyl substances (PFAS) but there is still limited information on the impact PFAS has on colorectal cancer.Aim: To review and examine the evidence available in the existing published literature showing an association between exposure to PFAS and colorectal cancer. Methods: In this narrative review using searches of PubMed, SCOPUS and Google Scholar, publications between 2003 and 2023 were identified to ensure the inclusion of all recent development in this area of research. Inclusion criteria included a focus on the association between PFAS/PFOS and …

Protection Against Cholera From Killed Whole-Cell Oral Cholera (Kocv) Vaccines: Systematic Review And Meta-Regression Of Randomized Control Trials And Observational Studies, Helena Hojeong Kwon

Public Health Theses

Introduction: Although killed whole-cell oral cholera vaccines (kOCVs) are widely used as a part of cholera control strategy, mixed evidence around the vaccine induced protection remains.Objectives: The primary objective of this systematic review was to update estimates of kOCV protection: vaccine efficacy and effectiveness. A secondary objective was to estimate the waning dynamic of kOCV protection by duration of follow-up. Methods: On August 15th, 2022, we searched for randomized control trials and observational studies that reported kOCV protection in low- and middle-income countries on PubMed, EMBASE, Scopus, ISI Web of Science, and The Cochrane Review Library with a start date …

Evaluating Environmental Risk Factors For Community-Associated C. Difficile Infection In New Haven County, Connecticut, 2016-2021, Hannah Liat Litwak

Public Health Theses

Background: Clostridioides difficile infection (CDI) is classified as an urgent threat to public health and has been increasing in incidence and severity. CDI is commonly considered hospital- acquired; however, rates of community-associated CDI (CA-CDI) have been increasing and now make up more than 50% of cases reported. Risk factors for CA-CDI exposure are poorly understood and inadequately studied. This study uses regression to evaluate if community characteristics are associated with CA-CDI incidence at the census tract level in New Haven County. The goal is to determine if where someone lives in proximity to these potential risk factors may contribute to …

Drivers Of Global Waterborne Disease Transmission Following Extreme Precipitation Events: A Systematic Review, Claire Latendresse

Public Health Theses

Precipitation events such as hurricanes, typhoons, and heavy rainfall can have devastating impacts on water and sanitation infrastructure around the world and have led to large-scale waterborne outbreaks. As climate change amplifies the frequency and intensity of extreme weather events, it is also triggering an increase in waterborne disease transmission. This master’s thesis consists of a systematic review of academic literature pertaining to extreme precipitation events and the pathways by which they trigger waterborne outbreaks.

A systematic review of the literature in PubMed was conducted to identify waterborne disease outbreaks associated with extreme precipitation. The initial search yielded 3,248 results …

A Geospatial Analysis Of Demographic Characteristics And Environmental Burdens In Communities Near Superfund Sites, Long Island, New York, Fintan Mooney

Public Health Theses

Nassau and Suffolk Counties of Long Island, New York, have over 30 federal Superfund sites, which may contribute to increased health inequities in nearby communities due to potential drinking water contamination and air pollutant emissions. We assessed the proximity to Superfund sites on Long Island in relation to community demographics and the presence of other environmental burdens. Data were obtained from the 2022 United States Environmental Protection Agency’s Environmental Justice Screening and Mapping Tool (EJScreen) and included proximity to Superfund sites (operationalized through the EJScreen distance weighting score), presence of other environmental hazards, and sociodemographic variables from the U.S. Census …

Characterizing Populations Living Near Concentrated Animal Feeding Operations: Implications For Health Equity And Environmental Justice, Leah Salzano

Public Health Theses

Current literature has highlighted that concentrated animal feeding operations (CAFOS) are associated with adverse health outcomes among populations living in close proximity to the farms and that, in certain states, vulnerable populations may be disproportionately exposed to CAFOs. However, none of the existing studies have assessed the sociodemographic makeup of areas highly exposed to CAFOs across a diverse geographic range. Using locations of CAFOs across six states with robust operations, we conducted logistic regression models assessing the likelihood of high exposure vs. low exposure at the census tract level for each 10% increase in sociodemographic variables (percent unemployed, percent minority, …

Analyzing The Trophic Structure Of Ancient Communities, Jack Oliver Shaw

Yale Graduate School of Arts and Sciences Dissertations

Since the proliferation of animal life during the Cambrian (ca. 541-485 million years ago), the biosphere has changed considerably, including long-term trends towards increasing taxonomic and functional diversity within and across ecosystems. Whether and how long-term trends in the evolution of life affected the Earth system is an active area of research, in part because the function and dynamics of ecosystems cannot be inferred by simply summing up the effect of all individuals present. Instead, the effect of diversity on ecosystem-level properties is modulated by the network of links between individuals, including trophic (e.g., predator-prey) and non-trophic (e.g., symbiosis and …

Evolutionary Dynamics Of Rapid, Microgeographic Adaptation In An Amphibian Metapopulation, Adam Zachary Andis Arietta

Yale Graduate School of Arts and Sciences Dissertations

Wild organisms can rapidly adapt to changing environments, even at fine spatial scales. This fact prompts hope that contemporary local adaptation may buffer some of the negative anthropogenic impacts to ecosystems. However, there are limits to the pace of adaptation. Understanding the adaptive potential—and limitations—of individual species at fine-resolution is an important task if we hope to accurately predict the repercussions of future climate and landscape change on biodiversity. My dissertation takes advantage of an uncommonly long-observed and closely-studied system to paint a comprehensive picture of evolution over time in association with shifts in ecological contexts. In this dissertation, I …

Critical Theory In Revolt: Angela Davis, Rudi Dutschke, Hans-Jürgen Krahl And The Frankfurt School, 1964-1972, Cecilia Sebastian

Yale Graduate School of Arts and Sciences Dissertations

This dissertation charts an alternative history of Frankfurt School Critical Theory through its critical reception and appropriation by students involved in anti-authoritarian, anti-capitalist, and anti-imperialist social movements in the United States and West Germany in the 1960s and 1970s. There, many student readers of the tradition, including those named in the title, found opportunities to refine and critique their mentors’ ideas about capitalism and the state, racism and fascism, technology and mass culture, and the nexus of theory and praxis. They resisted the domestication of Critical Theory into the purely academic discourse of philosophy, sociology, and political theory, and instead …

The Impacts Of Unconventional Oil And Gas Development On Drinking Water And Children’S Health, Cassandra J. Clark

Yale Graduate School of Arts and Sciences Dissertations

Unconventional oil and gas development (UOGD) combines horizontal drilling with hydraulic fracturing (the pressurized injection of millions of gallons of water and chemicals) to extract fossil fuels such as natural gas from deep rock deposits. UOGD has led to community concern over environmental hazards, such as water contamination, and health hazards, such as cancer. This dissertation examines the impacts of UOGD on communities in the Appalachian Basin from the perspective of three disciplines: exposure science, environmental justice, and epidemiology (background and overall aims summarized in Chapter 1). Chapter 2 investigates whether UOG exposure through household groundwater is captured by spatial …

Multidisciplinary Studies On The Social And Health Implications Of Stormwater Management And Flash Flooding, Alisha Yee Chan

Yale Graduate School of Arts and Sciences Dissertations

Research on stormwater management and flash flooding is of the upmost importance given the increase in severity of storm events from climate change and the rising installation of impervious surfaces from urbanization. This dissertation presents three studies that reveal social and health implications of stormwater management and flash flooding. Stormwater control measures (SCMs) (i.e., green infrastructure) are advantageous methods of stormwater management. However, studies suggest that urban greening may be associated with gentrification, displacing racially/ethnically minoritized groups due to increased housing costs and loss of feelings of belonging. For the first study presented in this dissertation, I analyzed whether there …

A Silent Injustice: Air Pollution As A Contributing Factor Of Covid-19 Health Disparities, Spencer Johnson

The Yale Undergraduate Research Journal

COVID-19, the disease caused by SARS-CoV-2 has had a disproportionate impact on Black communities throughout the United States. This paper suggests that air pollution may be a factor for why Black individuals experience markedly poorer health outcomes after contracting COVID-19. It establishes that not only are Black Americans exposed to disproportionate amounts of air pollution, but also that many air pollution-related ailments are the exact ones that have been clinically proven to make COVID-19 more fatal. AV Whe UniWed SWaWeV diVcXVVeV ZhaW a ³neZ noUmal´ entails for healthcare practice and public health policy, this paper makes the case for why …

Making The Invisible Visible: Ageism As A Social Determinant Of Elder Abuse, E-Shien Chang

Yale Graduate School of Arts and Sciences Dissertations

Background: Elder abuse affects one in six community-dwelling older adults globally every year and can lead to great bodily and psychological harm and death. Despite elder abuse has been recognized as a global health problem, there are several knowledge gaps that have impeded the development of elder abuse prevention science. At the structural level, evidence regarding the effects of broader societal attitudes, laws and policies in enabling abusive acts toward older persons is lacking but critical for tailored preventions. At the individual level, existent research has disproportionately focused on victims rather than abusers, a problematic trend given abuser characteristics can …

Caesarean Delivery Among Women Of Color Is Associated With Risk Of Early Childhood Developmental Delays In Brazil, Haley Case

Public Health Theses

Background. Poverty, racism, and other sources of oppression threaten children’s nurturing environments and associated early childhood development (ECD). Women of Color and their children are disproportionately exposed to risk factors for poor ECD in Brazil. There is a growing body of evidence supporting the claim that unnecessary cesarean section (CS) is associated with poor maternal health outcomes and ECD delays. There is an existing gap in the literature on risk factors, including obstetric factors, of poor ECD among children of Women of Color in Brazil.

Objective. The objective of this thesis was to investigate factors, including obstetric characteristics of CS …

Co-Distribution Of Ambient Light At Night And Incidence Of Human Cancers And Covid-19, Yidan Meng

Public Health Theses

Introduction and BackgroundThere are increasing concerns about the effects of artificial lights on human health, including hormone-related disease and immune functions. In January 2020, the outbreak of COVID-19 disrupted everyone’s life, and people who infected have various severity. Thus, we want to analyze whether people exposed to different ambient light at night (LAN) levels make them more susceptible to COVID-19 for our summer research. Besides the effects of LAN on immune functions, we also discussed the association of LAN and multiple cancers in seven states of Northeastern U.S. We used similar statistical and geographic analysis methods and separate them into …

Investigation On The Association Between Unconventional Oil And Gas Development And Traffic Accident Rates In Ohio, Hubian Wang

Public Health Theses

The oil and gas drilling activities had greatly developed in Ohio in past decade. Unconventional natural gas development is a newly developed technology, which requires more heavy-truck trips in the drilling process. Limited studies investigated the association between drilling activities and increased rate of traffic accidents. Ecological study was conducted to analyze the association. Number of unconventional wells were obtained as exposure variable from Ohio department of natural source, and the data of traffic crashes were collected as outcome variable from Ohio department of public safety. Other variables including sociodemographic data and spatial distribution of primary roads were examining as …

Association Between Opening A Jail And Sexually Transmitted Infections In Rural Counties Across The United States, Tyler Harvey

Public Health Theses

Abstract

Objective

To estimate the effect of openings jail in rural counties on county-level chlamydia, gonorrhea, and syphilis prevalence rates.

Methods

We used county-level data from the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (2005-2017) to obtain chlamydia, gonorrhea, and syphilis rates, and the American Correctional Association’s National Jail and Adult Detention Directory (2013-2014) to locate rural jail openings. Using a generalized synthetic control method, we estimated the effect of opening jails in 41 rural counties between 2010 and 2012 across the United States on sexually-transmitted infections.

Results

We found an average treatment effect for chlamydia prevalence …

Targeting The Inequality In Quality Improvement, Raquel Maria Davis

Public Health Theses

Objective. To use Casalino et al.’s (2007) proposed causal pathways of how pay-for-performance (P4P) can exacerbate racial/ethnic health care disparities as a framework for analyzing the literature and determine the adequacy of the evidence.

Data Sources/Study Setting. Existing literature (gray and peer-reviewed) on pay-for-performance and racial/ethnic health disparities identified from the Ovid Medline database.

Conceptual Framework. Casalino et al.’s four casual pathways include: “Pathway 1: Reduction in income for physicians in poor minority communities,” “Pathway 2: ‘Color-blind’ quality improvement programs,” “Pathway 3: ‘Teaching to the test’ might disproportionately affect minorities,” and “Pathway 4: Avoiding patients perceived as likely to lower …

Prep Uptake, Adherence, And Persistence: Qualitative Interviews With Women Experiencing Ipv, Ipv Service Providers, And Healthcare Providers, Amy Janet Caplon

Public Health Theses

Background: Intimate partner violence (IPV) has been associated with HIV susceptibility and

acquisition. Studies have found that women who had experienced IPV were at least three times more likely to have a diagnosis of HIV. Women are interested in taking PrEP, however barriers to uptake, adherence, and persistence are not widely known, and present knowledge excludes experiences of healthcare providers and IPV service providers. In this qualitative study, we examined the perceived facilitators and possible solutions to PrEP uptake, adherence, and persistence. This was done using a sample of women experiencing IPV, Reproductive Health Providers, PrEP Providers, and IPV service …