I. Introduction
The use of maps to explain and predict patterns of disease spread and to support epidemiological reasoning is well established in medical research [1]. Disease maps date back at least to the late 18th century, and feature among the prime examples of the usefulness of information visualisation [2], [1]. More recently, computing power and interactive techniques have allowed statistical modelling to be integrated into more sophisticated maps that support assessment of disease transmission risks [3]. Geographical information systems (GIS) have also been built which depict temporal as well as spatial data, allowing for a more principled integration of time-based data at different levels of coverage [4]. Good support for integrated visualisation of these dimensions is regarded as crucial for the successful use of such systems in epidemiology research, specially in the area of emerging infectious diseases [5].