Thesis (MPH.) -- University of Limpopo, 2021 / Background: Chronic illnesses, including non-communicable diseases (NCDs), continue to be a public health concern, globally, and contribute to the high burden of diseases. These health challenges have led to the introduction of community health workers (CHWs) in both developed and developing countries as a way of dealing with these challenges. It is more than five years since ward-based outreach teams (WBOTs) were introduced into the Julesburg area in order to respond to the needs of the community, based on the government’s focus on quadruple burden of diseases. The researcher is aware of the increasing workload, unclear roles and responsibilities, different approaches to CHWs’ work taken, and the ever-changing focus of their work, based on the community needs and diseases that the community faces at a particular time. It is for this reason that the researcher is interested in understanding the CHWs’ experiences and the manner in which they cope with challenges when working in their ever-changing environment, workload, work focus and roles and responsibilities. Methods: A qualitative exploratory, descriptive and contextual study approach was used; data was collected using focus group discussions with CHWs and one-on-one interviews with key informants, using their supervisors to gather more information that could not have been shared by CHWs. Result: The findings from the focus group discussions revealed that the CHWs have a high workload, while receiving stipend and are not permanently employed. CHWs have had experiences that make them feel unimportant and not needed, as well as enduring poor working conditions without sufficient personal protective equipment (PPE). Even though they experience dissatisfaction, they are passionate about continuing with their community-based work for many years, evidenced by those who have up to 22 years of service.

Over the past decade, and accelerated due to the COVID-19 pandemic, there has been increasing adoption of decentralized diagnostic testing, where the testing is brought closer to the patient. This trend has largely been fueled by the development of more accurate diagnostic tools and faster and more reliable data connectivity. Decentralized testing has been shown to greatly reduce turnaround times while increasing accessibility to users in remote regions. However, there are challenges that limit its widespread adoption. In this dissertation, we detail the development of tools and technologies to overcome these barriers and expedite the shift towards decentralized diagnostic testing. First, we demonstrate the ability to develop point-of-care (POC) diagnostic tests with performance that rivals that of traditional lab-based methods. We developed a rapid, multiplexed, microfluidic serological test for Lyme disease, a tick-borne disease caused by the Borrelia burgdorferi bacterium. The recommended testing, the standard 2-tiered (STT) approach, is not sensitive for early-stage infections, is labor-intensive, has long turnaround times, and requires the use of two immunoassays (enzyme-linked immunosorbent assay (ELISA) and the Western Blot). We developed a standalone multiplexed sandwich ELISA assay and adapted it to the mChip microfluidic platform. We validated the assay on a rigorously characterized panel of human serum samples and demonstrated that our approach outperforms the STT algorithm on sensitivity while matching its specificity. The form factor of this technology is amenable to use in physician’s offices and urgent care clinics. We also showed exploratory work towards adapting the mChip platform for diagnosis of Zika disease, a mosquito-borne disease caused by the Zika virus, and acute kidney injury, a syndrome characterized by loss of kidney excretory function. Next, we worked on increasing the adoption of rapid diagnostic tests for self- and partner-testing designed to be used in at-home settings. We developed a smartphone application to be used alongside the INSTI Multiplex test for detecting HIV and syphilis infections. The application was designed to provide users with i) instructions on running the test, ii) an automated deep-learning-based image interpretation algorithm to interpret the rapid test results from a smartphone image, iii) a way to save test results and display/share them, and iv) resources for follow-up care. We adopted a user-centered, iterative design process where we worked with a cohort of study participants composed of men who have sex with men and transgender women at high risk for contracting sexually transmitted infections. We then field tested the application with 48 participants over a duration of three months and found high acceptability for the application, both in terms of functionality and helpfulness. Finally, we sought to address a key limitation with deep-learning-based image classification techniques, specifically, the requirement for large numbers of annotated images for training. We developed a deep-learning image interpretation algorithm that could be quickly adapted to new rapid test kits using only a fraction of the images that would otherwise be needed for training the model. The interpretation algorithm followed a three-step, modular process. First, the rapid test kit and the membrane were extracted from the smartphone image. Second, the constituent zones were cropped from the extracted membrane. Finally, a classifier detected the presence or absence of a line in the individual zones. Fast adaptation was demonstrated by adapting a base model, trained using images of a single COVID-19 rapid test kit, to four different rapid test kits, each with different form factors, using few-shot domain adaptation. After training with 20 or fewer images, the classification accuracies of all the adapted models were > 95%. This approach can provide a digital health platform for improved pandemic preparedness and enable quality assurance and linkage to care for consumers operating new LFAs in widespread decentralized settings. Together, these methods provide a suite of tools that could expedite the shift towards decentralized, POC testing.

El presente trabajo de investigación tiene como objetivo evaluar la deseabilidad, factibilidad comercial y la viabilidad financiera de crear e implementar un restaurante especializado en comida saludable para personas que necesiten cuidar su alimentación para controlar enfermedades no trasmisibles (diabetes, hipertensión, obesidad y otros). El plan de negocio contiene el análisis de mercado teniendo en cuenta las tendencias mundiales que muestran un crecimiento sostenido por el interés de mantener una vida saludable a través de una alimentación sana. El restaurante va dirigido a personas con enfermedades no transmisibles con NSE A y B, mayores de 18 años con poder adquisitivo, modernas, progresistas y sofisticadas que priorizan su alimentación con cuidados nutricionales. Adicionalmente, se realizó un sondeo de mercado a fin de poder identificar información necesaria que valida y ayuda definir el modelo de negocio. El restaurante estará ubicado en Miraflores, el cual funcionará brindando almuerzos y cenas. La carta será diseñada y supervisada por un Chef altamente calificado y un nutricionista especializado. Para el inicio de las operaciones se necesitará una inversión de s/ 541,073 dicho monto se utilizará en la compra de equipos y capital de trabajo. La estructura de capital estará distribuida con 60% de deuda y 40% de capital propio teniendo una relación D/E de 1.5. Finalmente, luego de realizar el análisis financiero se obtiene un VAN de s/ 271,680 y una TIR de 32% considerando una tasa de descuento del 13.65%, por lo que se concluye que el proyecto es rentable, viable y genera valor. / The present research work aims to evaluate the desirability, commercial feasibility and financial viability of creating and implementing a restaurant specialized in healthy food with special attention to people who want to take care of their diet to control non-communicable diseases (diabetes, hypertension, obesity and others). The proposed business contains the market analysis considering world trends that show sustained growth in the interest of maintaining a healthy life through healthy eating. The restaurant is aimed at people with non-communicable diseases with NSE A and B, over 18 years of age with purchasing power, modern, progressive and sophisticated who prioritize their diet with nutritional care. In addition, a market survey was carried out in order to identify necessary information that validates and helps define the business model. The restaurant will be in Miraflores, which will operate providing lunch and dinner. The menu will be designed and supervised by a highly qualified Chef and a specialized nutritionist. For the start of operations, an investment of s / 541,073 will be needed. This amount will be used for the purchase of equipment and working capital. The capital structure will be distributed with 60% debt and 40% equity, having a D / E ratio of 1.5. Finally, after carrying out the financial analysis, a NPV of s / 271,680 is obtained and an IRR of 32% considering a discount rate of 13.65%, which is why it is concluded that the project is profitable, viable and generates value. / Trabajo de investigación

Many infectious diseases are spread through interactions between susceptible and infectious individuals. Keeping track of where each exposure to the disease took place, when it took place, and which individuals were involved in the exposure can give public health officials important information that they may use to formulate their interventions. Further, knowing which individuals in the population are at the highest risk of becoming infected with the disease may prove to be a useful tool for public health officials trying to curtail the spread of the disease. Epidemiological models are needed to allow epidemiologists to study the population dynamics of transmission of infectious agents and the potential impact of infectious disease control programs. While many agent-based computational epidemiological models exist in the literature, they focus on the spread of disease rather than exposure risk. These models are designed to simulate very large populations, representing individuals as agents, and using random experiments and probabilities in an attempt to more realistically guide the course of the modeled disease outbreak. The work presented in this thesis focuses on tracking exposure risk to chickenpox in an elementary school setting. This setting is chosen due to the high level of detailed information realistically available to school administrators regarding individuals' schedules and movements. Using an agent-based approach, contacts between individuals are tracked and analyzed with respect to both individuals and locations. The results are then analyzed using a combination of tools from computer science and geographic information science.

This study investigated caregivers' perceptions with regard to vaccine-preventable diseases in terms of six constructs of the Health Belief Model. A qualitative research design that is explorative, descriptive and contextual in nature was employed in order to understand and describe the perceptions influencing access and utilisation of services that lead to missed immunisation opportunities and consequently outbreaks of vaccine-preventable diseases. The data-collection techniques were individual unstructured in-depth interviews, field notes and clinical records. The sample consisted of twenty two (N=22) caregivers who volunteered to be interviewed. The study has highlighted that caregivers' perceptions or cognitive factors play an important role for having children in completing immunisation schedule to protect the public from vaccine-preventable diseases. It is recommended that mass media programmes are needed to address the role of vaccines in reducing high morbidity and mortality rates caused by vaccine preventable diseases and improvement in access to immunisation services. / Health Studies / MPH (Health Studies)

Obesity and obesity-related diseases – such as type 2 diabetes – have become the most crucial indicators of population health in the 21st century. Formerly understood as ‘diseases of affluence’, obesity is now prevalent in the Global South posing serious risk to socioeconomic development. This is particularly true for rapidly developing countries where nutrition transitions are most apparent. There are many factors which impact on risk of obesity (e.g. gender, culture, environment, socioeconomic status, biological determinants). The problem is further aggravated within small island developing states where food security is exacerbated by factors associated with globalization and development. The thesis examines the surge of obesity and type 2 diabetes within Caribbean populations, using Barbados as a case study. A holistic approach was applied using an ecological health model. Moving away from the lifestyle model, the theoretical framework underpinning included sub-theories (e.g. social constructivism, feminism, post-colonial theory, concepts of memory and trauma).

Chong, Ka Chun. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 125-141). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Obesity and obesity-related diseases – such as type 2 diabetes – have become the most crucial indicators of population health in the 21st century. Formerly understood as ‘diseases of affluence’, obesity is now prevalent in the Global South posing serious risk to socioeconomic development. This is particularly true for rapidly developing countries where nutrition transitions are most apparent. There are many factors which impact on risk of obesity (e.g. gender, culture, environment, socioeconomic status, biological determinants). The problem is further aggravated within small island developing states where food security is exacerbated by factors associated with globalization and development. The thesis examines the surge of obesity and type 2 diabetes within Caribbean populations, using Barbados as a case study. A holistic approach was applied using an ecological health model. Moving away from the lifestyle model, the theoretical framework underpinning included sub-theories (e.g. social constructivism, feminism, post-colonial theory, concepts of memory and trauma).

This study investigated caregivers' perceptions with regard to vaccine-preventable diseases in terms of six constructs of the Health Belief Model. A qualitative research design that is explorative, descriptive and contextual in nature was employed in order to understand and describe the perceptions influencing access and utilisation of services that lead to missed immunisation opportunities and consequently outbreaks of vaccine-preventable diseases. The data-collection techniques were individual unstructured in-depth interviews, field notes and clinical records. The sample consisted of twenty two (N=22) caregivers who volunteered to be interviewed. The study has highlighted that caregivers' perceptions or cognitive factors play an important role for having children in completing immunisation schedule to protect the public from vaccine-preventable diseases. It is recommended that mass media programmes are needed to address the role of vaccines in reducing high morbidity and mortality rates caused by vaccine preventable diseases and improvement in access to immunisation services. / Health Studies / MPH (Health Studies)

Obesity and obesity-related diseases – such as type 2 diabetes – have become the most crucial indicators of population health in the 21st century. Formerly understood as ‘diseases of affluence’, obesity is now prevalent in the Global South posing serious risk to socioeconomic development. This is particularly true for rapidly developing countries where nutrition transitions are most apparent. There are many factors which impact on risk of obesity (e.g. gender, culture, environment, socioeconomic status, biological determinants). The problem is further aggravated within small island developing states where food security is exacerbated by factors associated with globalization and development. The thesis examines the surge of obesity and type 2 diabetes within Caribbean populations, using Barbados as a case study. A holistic approach was applied using an ecological health model. Moving away from the lifestyle model, the theoretical framework underpinning included sub-theories (e.g. social constructivism, feminism, post-colonial theory, concepts of memory and trauma).