The MAHERY team has done substantial human health and epidemiological research in the Maroantsetra region and throughout Madagascar. Our nutrition research in Madagascar comprises three main projects: 1) a 15-month prospective cohort study of 700 individuals in 150 households that quantified the effects of ecological degradation of terrestrial systems on maternal and child health, in light of heavy reliance on the consumption of wildlife for human nutrition; 2) a 26-month prospective cohort study of nearly 1,000 individuals in 225 households in coastal Madagascar to understand the role of fisheries management on access to seafood for nutrition; and 3) a cross-sectional study of nearly 8,000 individuals in approximately 1,200 households in four regions of Madagascar to evaluate the role of seasonality and human migration in affecting food security and disease transmission. In all three of these projects, we are collecting very fine-scale dietary data (including food diaries), fecal samples, fingernails, anthropometric data, breastmilk, dried blood and frozen plasma samples. In each project, all individuals will have full nutritional profiles including zinc, ferritin, transferrin receptor, vitamin A, vitamin B12, AGP, CRP, and fatty acid profiles.
With rich qualitative and survey data and the above-listed biological samples, I am posed to answer interesting questions about the role of infectious disease (i.e. malaria, intestinal parasites, etc.) in affecting human nutritional status, the role of nutritional status in predisposing the onset of various infectious diseases, how diet affects the isotopic carbon, nitrogen, and mercury signatures in fingernails, how the exposure to wildlife or intestinal parasites may alter the microbial community in the human microbiome in either positive or negative directions, the relationship between the exposure to wildlife and zoonotic disease, and how dietary intake and maternal nutritional status affects the nutrient content of breast milk.
Our primary hypothesis is that changes in access to agricultural, aquatic and terrestrial systems for food leads to changes in risk of important nutritional deficiencies and that these various forms of malnutrition will, in turn, alter the burden of disease in affected populations. Because malnutrition is a preeminent public health risk factor and because diet is linked to the state of the natural environment for many populations in the developing world, investigation into the dietary impacts of changes in natural systems is fertile ground for researching linkages between ecosystem health and human health. Aquatic and terrestrial wildlife is the primary source of meat and income for more than a billion people in economically developing countries. Many of these people have diets in which the majority of calories come from a staple crop rich in carbohydrates but poor in many key nutrients. Terrestrial or marine wildlife provides critical vitamins, minerals, and macronutrients to supplement these starchy staple crops. Using a planetary health lens, we will continue to examine the role that natural resource management approaches can play in improving child health by ensuring access to critical nutrients.
The MAHERY research team also investigates the role of malaria in affecting human nutritional status and the role of nutritional status in predisposing an individual to the onset of infectious diseases, such as malaria. Ben Rice, a MAHERY board member, and graduate student at Harvad University is leading this work. We are also collaborating with Caroline Buckee, Sarah Volkman, Dan Hartl and Manoj Duraisingh of the Dept. of Immunology and Infectious Diseases at HSPH to understand the following aspects of malaria ecology in this region of Madagascar: 1) genotypic variation of malaria in these remote communities (this is of particular interest because Madagascar has the presence of all four types of human malarias); 2) use of our dietary intake and nutritional data to understand relationships between malaria and nutrition; 3) the relationship between Duffy negativity and P. vivax and P. falciparum; and 4) the presence of drug-resistant loci in malaria strains.
The fecal samples we are collecting will permit us to estimate a true prevalence and incidence of intestinal parasites and infections and conduct studies of the microbial community in the human microbiome. We have already used microscopy for parasite identification for many of these samples and will continue to process the remaining samples. Armed with these results, we can begin to understand the role these parasites may have on human nutrition, because we have detailed dietary intake data, incidence data on parasites, and nutritional status results from blood plasma.Prospectively, we are in the process of initiating a comprehensive, mHealth disease surveillance system in four communities in Madagascar, utilizing OpenSRP- a tablet-based surveillance system developed by Anu Shankar and colleagues. The primary objective of this work is to create and pilot a basic infrastructure for community-level epidemiological health surveillance so that 1) the government can have access to non-clinic-based disease prevalence and incidence data; and 2) local interventions can address health issues that are relevant to communities and have an established baseline to analyze impact. This platform is a new and innovative technique to register a full census of individuals within communities and to track local Malagasy’s health over time. These health incidence data can be connected with climate and habitat mapping and tracking data to understand the connections between microhabitats (forest structure, land-use planning, etc.), seasonal weather (and future weather predictions given climate change), and extreme weather events (frequent cyclones) and human health. By empirically connecting the environment and health with rich data streams, policy-makers and engaged community members will be able to develop interventions, adaptations and mitigation efforts to protect both the environment and human health.
1. Golden, C. D., Anjaranirina, E. J. G., Fernald, L. C. H., Hartl, D. L., Kremen, C., Ralalason, D. H., Ramihantaniarivo, H., Randriamady, H. J., Rice, B. L., Vaitla, B., Volkman, S. K., Vonona, M. A., and Myers, S. S. 2017. Cohort Profile: The Madagascar Health and Environmental Research (MAHERY) Study in Northeastern Madagascar. International Journal of Epidemiology. doi: 10.1093/ije/dyx071
- 2. Rice, B. L., Golden, C. D., Anjaranirina, E. J. G., Botelho, C. M., Volkman, S. K., & Hartl, D. L. (2016). Genetic evidence that the Makira region in northeastern Madagascar is a hotspot of malaria transmission. Malaria Journal, 15(1), 596.