Big Data Opportunities for Global Infectious Disease Surveillance
The definitive extent of infectious disease occurrence at the national level (red is certain presence, green is certain absence)  is combined with assemblies of known occurrence, presence points (red dots), to generate putative pseudo-absence points (blue dots). The presence and pseudo-absence data are then used in the analyses, with selected environmental covariates to predict disease risk, formally the probability of occurrence of the target disease. In this example a risk map of dengue is shown, shaded from low probability of occurrence in blue to high probability of occurrence in red . The arrows represent data flows.