PROJECT SUMMARY The NIA IMPACT Collaboratory COVID related supplement that funded the Long Term Care Data Cooperative [U54AG063546-02S6] established a cooperative that is compiling a centralized repository of nursing home electronic medical record (EMR) data from three different EMR vendors. Numerous nursing home companies using one of these three vendors have signed up as members, authorizing their EMR vendor to transfer clinically relevant data, complete with identifiers, to a centralized repository operating under the auspices of the American Health Care Association (AHCA) a membership association of most US nursing homes [https://www.ahcancal.org/Data- and-Research/Pages/LTC-Data-Cooperative.aspx]. In addition to the regulatory required Minimum Data Set information, EMR data being consolidated include all prevalent and incident diagnoses, orders, medication administration records, change of condition records, daily vital signs, incident reports, vaccinations, behavior tracking, daily changes in cognitive and physical functioning, and for some facilities, laboratory and diagnostic test results. To facilitate use of these data for the purpose of conducting public health surveillance, in close collaboration with leadership and research analysts at the Centers for Disease Control and Prevention, Brown University investigators propose to Investigate the validity of infection data in the nursing home EMR by exploring the viability of using the EMR data to identify two infectious conditions among nursing home residents. These will be selected in consultation with CDC officials and could range from the occurrence of SARS-CoV-2 and other pulmonary viruses to other common conditions like C-Difficile with the goal of creating indicators of the incidence of each type of infection that appears valid and reliably detected.