Surveillance systems collating individual-level data may limit timely information sharing during rapidly evolving, infectious disease outbreaks. We present a digital outbreak alert and notification system ( MUIZ) in which institutional-level data are reported, allowing real-time outbreak monitoring in elderly care facilities (ECF). We describe trends in the number of outbreaks, mean case number per outbreak, and case-fatality rate (deaths/recovered + deaths) of SARS-CoV-2 in ECF notified through MUIZ in the Rotterdam area (April 2020-March 2022). Overall, 369 outbreaks were reported from 128 ECF that registered with MUIZ (approximately 85% of all ECF), and 114 (89%) notified at least one SARS-CoV-2 outbreak. Trends were consistent with the concurrent national epidemiology and societal control measures in place. MUIZ is a simple outbreak surveillance tool that was highly adopted and acceptable to users. Dutch PHS regions are increasingly adopting the system and it has potential for adaptation and further development in similar institutional outbreak settings.