Alberta reported 57 new cases of COVID-19 on Tuesday, the largest single-day number recorded so far since the pandemic began.

The province also reported its second fatality from the illness, with the death of a woman in her 80s in a Calgary nursing home.

Two other patients and one staff member at the McKenzie Towne Continuing Care Centre in southeast Calgary have also tested positive for coronavirus, Dr. Deena Hinshaw, Alberta's chief medical officer of health, said at her daily news conference Tuesday from the legislature.

"News of this death and other potential infections in a long-term care facility will be distressing for many people," Hinshaw said.

"You may be listening to me right now from a long-term care facility, or you may have a loved one who lives in one. Although I want to reiterate that most people who become ill with COVID will experience only mild symptoms, it can make others very sick.

"This is why we have taken the extreme measures we have and why I cannot emphasize enough the importance for all Albertans to follow all public health guidance."

Eleven other residents in the same nursing home are also showing symptoms of the illness. The two other residents confirmed to have COVID-19 are both are in stable condition, Hinshaw said.

The new cases bring the province's total number of cases to 358.

Nineteen people are currently in hospital, including seven in intensive-care units.

The latest on the COVID-19 pandemic from Edmonton, Calgary and Saskatchewan 15:27

An outbreak in a nursing home is particularly worrisome for public health officials since the residents are elderly and likely already have underlying health concerns.

"In long-term care and other continuing-care facilities, where some of our most vulnerable citizens reside, we have taken additional measures to prevent the spread of COVID-19," Hinshaw said.

Tests are continuing on the 11 residents in the nursing home who are showing symptoms.

"The staff member who tested positive for the virus had no travel history and did not work while symptomatic," Hinshaw said. "Staff who were in contact with residents who tested positive will be identified and isolated."

Last week the province restricted access to long-term facilities to only essential visitors, all of whom undergo screening prior to entering.

"We are continuing to look at additional measures for continuing care and long-term care facilities that operators and staff could implement to further limit the risk for residents," Hinshaw said. "As soon as these are finalized, we will communicate them."

The majority of the 358 cases are located in the Calgary zone. The number of cases by region:

Calgary zone: 214

Edmonton zone: 86

Central zone: 28

North zone: 20

South zone: 8

Unknown: 2

Twenty-eight cases reported so far are thought to have been transmitted within the province, and it is those numbers that public health officials are watching most closely.

Hinshaw also gave an update on cases related to an Edmonton curling bonspiel earlier this month. Twelve of 47 health-care workers, including three doctors from Red Deer, who attended the bonspiel have now tested positive for coronavirus.

"From the three cases in Red Deer, although they each worked less than a day while symptomatic, a total of 58 patients and 97 other health-care workers have been, or will be, contacted as potential close contacts of these three," Hinshaw said.

"As I said yesterday, symptoms can be mild, and these physicians did not know they had been exposed to a case of COVID-19 when they become ill. They simply finished out their shifts that they were doing, went home and self-isolated at that point.

"This experience is a reminder that it is critical to immediately self-isolate at the first sign of symptoms. This can be challenging and the health system needs to support health-care workers to take these steps."

On Monday, Alberta announced that it would be limiting testing to people who are showing symptoms and who fall within certain at-risk groups. Those groups include people hospitalized with respiratory illness, people living in a continuing-care or similar facility, health-care workers with respiratory symptoms, and international travellers who returned between March 8 and March 12.