| This dissertation investigates the interrelationships between macro-political, social, and economic polices, human migration, agricultural development, and malaria transmission on the Brazilian Amazon frontier. The ultimate goals are to: (i) identify the local determinants of malaria transmission, and thereby provide the necessary information for the design of more efficient malaria mitigation policies; and (ii) establish a spatially explicit methodology for analysis of malaria risk in complex ecosystems on the Amazon frontier. The analysis is focused on the Machadinho Settlement Project, located in the state of Rondonia. Field survey data collected in 1985 (the inception of the settlement), 1986, 1987 and 1995, provide information on health, demographic, economic, social, ecological, behavioral, and agricultural characteristics. I adopted a three-step methodological approach that combined spatial analysis, geostatistical tools, and fuzzy-set models. This innovative approach facilitated the analysis of malaria risk factors at a local level. Applying Grade of Membership models I obtained nuanced profiles of low and high malaria risk for each of the four years studied, and for different levels of spatial aggregation. The results highlighted major variation over time and space, and characterized the subtle interface between natural and man-made environments for malaria transmission. They also showed that, as the spatial level of aggregation was refined, more detailed risk profiles were obtained. The risk profile representations facilitated the specification of a set of strategies that should be implemented in colonization projects, targeted in both time and space, for increasing the effectiveness and reducing the costs of malaria mitigation in frontier settlements. Important features of the proposed mitigation strategies include: (i) all persons arriving at new settlement projects should be tested and treated for malaria before they occupy their plots; (ii) environmental management should be a central focus in the early stages of settlement; (iii) personal behavior should be the focus of interventions after there is substantial land clearance and stabilization of the area; (iv) financial support for house construction must be guaranteed; (v) education about malaria should be provided to all settlers in the early stages of the project; (vi) promotion of a diverse array of supportive community organizations is essential. |
