Geographic Information Systems (GISs) are composed of useful tools to map and to model the spatial distribution of events that have geographic importance as schistosomiasis. This paper is a review of the use the indicator kriging, implemented on the Georeferenced Information Processing System (SPRING) to make inferences about the prevalence of schistosomiasis and the presence of the species of Biomphalaria, intermediate hosts of Schistosoma mansoni, in areas without this information, in the Minas Gerais State, Brazil. The results were two maps. The first one was a map of Biomphalaria species, and the second was a new map of estimated prevalence of schistosomiasis. The obtained results showed that the indicator kriging can be used to better allocate resources for study and control of schistosomiasis in areas with transmission or the possibility of disease transmission. 1. Introduction Schistosomiasis mansoni is an endemic disease, typical of developing countries [1, 2]. In Brazil, the schistosomiasis is caused by the etiological agent Schistosoma mansoni, whose intermediate host is species of mollusk of the Biomphalaria genus. The S. mansoni was introduced in Brazil by the African slavery trade during the sixteenth century [3]. The Brazilian port of Salvador and Recife received most of the slaves [4], originated from endemic regions. In the early eighteenth century, there was a large migration of slave labor due to the decline of sugar production in the Northeast of Brazil and the discovery of gold and diamond in the Minas Gerais State. It is estimated that one fifth of the population at that time moved to Minas Gerais [5], using the “ways of S？o Francisco” [6] as the main access route. Probably, in these early migrants also came to schistosomiasis. In Minas Gerais, there are seven species of Biomphalaria genus: B. glabrata, B. straminea, B. tenagophila, B. peregrina, B. schrami, B. intermedia, and B. occidentalis [7–9]. Come in these, only B. glabrata, B. tenagophila, and B. straminea have been found naturally infected by S. mansoni [10, 11]. B. glabrata is of great epidemiologic importance, due to its extensive geographic distribution, high infection indices, and effectiveness in the schistosomiasis transmission. Moreover, its distribution is almost always associated with disease occurrence [12]. B. tenagophila was found naturally infected by S. mansoni in state of Minas Gerais, and it is responsible for the focus maintenance in the city of Itajubá [13]. B. straminea, although had not been found infected in state of Minas Gerais, was considered
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