The field of public health informatics calls for the conceptualization, design, development, deployment, refinement, maintenance and evaluation of surveillance systems (3) . This project exemplifies the positive outcomes that can result from collaborative efforts within the informatics framework. It is anticipated that this system will serve as a model for other counties across the state and will lead to improved reporting of flu vaccination records across the State of Ohio and perhaps beyond. Introduction Spatial cluster analysis is considered an important technique for the elucidation of disease causes and epidemiological surveillance. Kulldorff's spatial scan statistic, defined as a likelihood ratio, is the usual measure of the strength of geographic clusters (1). The circular scan (2), a particular case of the spatial scan statistic, is currently the most used tool for the detection and inference of spatial clusters of disease. Kulldorff's spatial scan statistic for aggregated area maps searches for clusters of cases without specifying their size (number of areas) or geographic location in advance. Their statistical significance is tested while adjusting for the multiple testing inherent in such a procedure. However, as is shown in this work, this adjustment is not done in an even manner for all possible cluster sizes (3).