Visualization; open source; localized; situational awareness; biosurveillance Introduction An increase in tuberculosis (TB) among homeless men residing in Marion County, Indiana, was noticed in the summer of 2008. The Marion County Public Health Department (MCPHD) hosted screening events at homeless shelters in hopes of finding unidentified cases. To locate men who had a presumptive positive screen, the MCPHD partnered with researchers at Regenstrief Institute (RI) to create an alert for healthcare providers who use the Gopher patient management system in one of the city's busiest emergency departments. A similar process was used at this facility to impact prescription behavior (1). A similar method was also used at the New York City Department of Health and Mental Hygiene (2).