Investigating Communicable and Non-Communicable Diseases in Rural Madagascar

Abstract

This dissertation examines the high burden of infectious diseases and factors influencing health outcomes in rural Madagascar through the lens of the One Health Disparities (OHD) framework. Using a multi-dimensional approach. I identified how variation in exposure and susceptibility contributes to infection risk. Specifically, I found that Blastocystis exposure is associated with hand hygiene practices, while decreased sleep efficiency is linked to greater infection susceptibility. I also investigated the association of sleep, stress, hypertension and did not identify an association between sleep and stress or between sleep and hypertension, but I did identify gender and age-related health outcomes. First, in Chapter 2, I investigated Blastocystis infection in a low-resource setting, focusing on wealth, hand hygiene, and animal contact, as potential predictors of infection. Among 783 participants, 76.5% were infected with Blastocystis. Overall, I identified individuals who washed their hands without soap had higher odds of infection, while gender disparities also played a role, women having higher odds of infection. This study underscores the importance of hand hygiene and access to clean water in reducing infection risk and highlights gaps in our understanding of Blastocystis pathways of transmission. Next, in Chapter 3, I explored the relationship between sleep, stress, and hypertension. Using actigraphy-based measurements from 33 participants, I found that while perceived stress did not correlate with sleep, significant gender differences in sleep patterns emerged. Additionally, age was associated with elevated blood pressure, with cases observed as early as 20 years old. These findings highlight the importance of early hypertension screening and further research on the sociocultural drivers of cardiovascular risk in young adults. Finally, in Chapter 4, I examined the role of sleep in infection susceptibility using actigraphy data and serological analysis. I identified a significant negative association between sleep efficiency and antibody richness, suggesting that better sleep quality may support immune resilience. These findings emphasize the importance of incorporating sleep quality into global health research.