A Geographic Approach to Identifying Disease Clusters

Abstract

In recent years, several interesting trends have come together to help pave the way toward a better understanding of disease diffusion. First, geography’s traditional interest in map pattern analysis has been augmented by geographic information systems technology. Second, the identification of relatively new diseases, such as AIDS and ebola, and rapidly spreading diseases, such as West Nile virus and dengue, has stimulated interest in finding ways to thwart their diffusion. Third, ecologists and epidemiologists have come to recognize the usefulness of the spatial viewpoint. Finally, statisticians, ecologists, and geographers have developed new ways of identifying statistically significant disease clusters. As a result of these trends, the study of disease clusters has shed new light on the ecological characteristics of infectious diseases and on many environmentally induced health problems. In this paper, I will discuss a relatively new set of cluster statistics: local statistics. The emphasis, however, will be to show how these statistics aid in identifying the possible clustering and transmission of the dengue fever vector, the Aedes aegypti mosquito, in Iquitos, Peru. The female Aedes aegypti is the main carrier of the viruses responsible for dengue fever. The mosquito transmits the viruses by human blood feeding, which is part of the mosquito egg-laying process.