The Public Health Agency of Canada (PHAC) oversees the HIV and AIDS surveillance system (HASS), which collects and reports national data on HIV and AIDS diagnoses across Canada. Managed by the STBBI Surveillance Division, HASS monitors trends in HIV and AIDS diagnoses, tracks changes in demographic and transmission patterns, and ensures Canada meets both domestic and international reporting requirements. It provides valuable data on the epidemic's progression, helping to inform public health policies at the national, provincial/territorial, and local levels.The specific objectives of the project include providing aggregate data on infants and children exposed to HIV in utero, which will be included in PHAC’s annual HIV surveillance report. Additionally, the project aims to update the clinical status of children previously identified as perinatally exposed to HIV. These efforts ensure that Canada fulfills its national and international obligations related to perinatal HIV transmission and prevention. The HASS system also aims to describe the occurrence of HIV and AIDS in Canada and identify at-risk populations based on transmission modes.