CALGARY -- Drumheller Institution confirmed two staff members have tested positive for COVID-19 Thursday,  a spokesperson for Correctional Service Canada confirmed.

The employees who tested positive recently are self-isolating at home. Public health authorities are conducting contact tracing efforts, in an effort to limit the spread of the virus.

Correctional Service Canada and Alberta Health Services have contacted all staff to set up COVID-19 tests.

Thursday, there were no confirmed COVID-19 cases among inmates at Drumheller Instutition. Testing is voluntary for inmates, who are encouraged to consent to be tested if offered. Mass testing of inmates was being conducted Thursday at Drumheller.

For the moment, the institution is not accomodating visits. There's no movement into the facility except for essential staff, or out of the facility except for essential medical escorts. The institution, the spokesperson said, is operating on a modified routine for health purposes in order to maintain safety of staff and offenders.

An outbreak at the Calgary Correctional Centre has grown to 118 confirmed cases, including 100 inmates, after a number of inmates who previously tested negative were re-swabbed.