Both patients were treated at Saint Joseph's Hospital in Saint John, New Brunswick, where the surviving patient remained in serious condition on Sunday with necrotizing fasciitis, better known as flesh-eating disease, hospital officials said.
A 37-year-old woman and another patient were discharged from the hospital after undergoing surgery last week, the hospital said. They were both subsequently admitted back to hospital and kept in isolation.
Hospital authorities said some hospital workers and others who might have been in contact with the two have been given antibiotics in the hope of stopping the disease from spreading.
But in a statement to reporters, Dr James O’Brien, chief of staff at the Atlantic Health Services Corporation said the disease was under control.
"We have instituted precautions to contain the spread of this infection and now feel the situation is under control as no new cases have developed," he said.
Necrotising fasciitis begins with streptococcus A bacteria. Most who are exposed to the bacteria do not get sick and even among those who do become ill, very few get flesh-eating disease. The disease however strikes rapidly and is frequently fatal.
In 1994, former federal cabinet minister Lucien Bouchard, then prime minister of Quebec, lost a leg when he was struck with necrotising fasciitis.
The spokesman at Saint John's Hospital said it was not yet known how or why the latest outbreak occurred.