Ecosystem change, market participation, and human health in villages proximate to Parc National de Marojejy.

Abstract

Human activities, including agricultural practices, have marked impacts on ecosystems that can affect food security, health, and livelihoods. These changes can affect human health by increasing infectious disease transmission between humans and animals. Furthermore, increased engagement with market economies through selling cash crops and purchasing consumer goods (i.e., market integration) can alter diet and behaviors, which may contribute to chronic diseases. The area around the Parc National de Marojejy in the SAVA region of northeast Madagascar has undergone considerable land use and economic changes in recent decades. Using One Health and evolutionary medicine frameworks, we conducted several empirical studies in multiple villages to explore linkages among animal and human health, ecosystem change, and market integration. We employed a range of methods including household and social network surveys, focus groups, and biological samples from humans, and wild and domestic animals. We confirmed the presence of infectious disease agents such as Leptospira, Blastocystis, canine hookworm (Ancylostoma ceylanicum), human hookworm (Necator americanus), hantaviruses, astroviruses paramyxoviruses, and coronaviruses. Among chronic diseases, hypertension was high among the study population, and people tend to exhibit short and fragmented sleep. Access to healthcare remains a challenge in the region, but participation in vanilla markets could lower these barriers by providing health insurance through vanilla certification schemes. We found that variation in land use, shared habitats, contact points, and social networks can all influence the potential for disease transmission. We are currently engaged in more in-depth studies in additional villages to better understand how environmental changes and economic development in Madagascar are contributing to a changing health landscape.