The Health Protection and Promotion Act requires that each public health unit in Ontario collect information about people with reportable diseases in their jurisdiction and report it to the Ministry of Health and Long-Term Care (MOHLTC). This information is used for local, provincial and national surveillance.
RDIS stands for Reportable Disease Information System. From 1989 to 2005, it was the provincial database used by public health units to report information on cases of reportable diseases to the MOHLTC. In April 2005, iPHIS replaced RDIS and key data stored in RDIS dating back to 1989 was converted to iPHIS.
The numbers of cases of reportable diseases included in RDIS is an underestimate of the actual numbers since not all people with a reportable disease seek medical treatment, and therefore the disease goes unreported.