An important component of RODS that currently is used only at the UPMC Health System in Pittsburgh is the Health System Resident Component (HSRC). The HSRC is located within the firewall of a health system and connects directly to the HL7 message router. The HSRC currently receives a diverse set of clinical data from the HL7 message router including culture results, radiology reports, and dictated F i g u r e 3. Health care registrations view in the Main screen of RODS. The Main screen alternates views every 2 minutes among data types available in the public health jurisdiction. The figure shows eight plots of health care registration data-total visits, botulinic, constitutional, gastrointestinal (GI), hemorrhagic, neurological, rash, and respiratory. After 2 minutes, over-the-counter data will be displayed. The Main screen can be used as a ''situation room'' display. emergency room notes. Its purpose is to provide additional public health surveillance functions that would not be possible if it were located outside of the firewall due to restrictions on the release of identifiable clinical data. The HSRC uses patient identifiers to link laboratory and radiology information to perform case detection. In the past, we have used HSRC to monitor for patients with both a gram-positive rod in a preliminary microbiology culture report and ''mediastinal widening'' in a radiology report. The HSRC is a case detector in a distributed outbreak detection system that is capable of achieving much higher specificity of patient diagnostic categorization through access to more information.