Toronto ? Toronto health officials on Thursday said Legionnaires’ disease was likely the cause of 16 deaths at a Toronto nursing home and, while relieved they had found the culprit, warned more deaths were possible before the bacteria was fully contained.

Dr. David McKeown, the chief medical officer for Public Health Toronto, said there had been no new deaths since Wednesday, when six more elderly people residing at the Seven Oaks Home for the Aged succumbed to the bacteria.

“We have a lot of sick people in hospitals still, so I’m not going to make any more predictions about deaths,” he said.

In all, 70 residents, 13 employees and five visitors to Seven Oaks have been affected by the elusive bacteria and at least 45 were hospitalized Thursday.

Though officials had earlier ruled out Legionnaires’ based on preliminary tests, they said cultures taken from autopsies, which took several days to grow, proved positive.

“We’ll continue to look for other possibilities, but we feel pretty confident … we’re dealing with Legionnaires’ disease,” said Dr. Donald Low, chief microbiologist at Mount Sinai Hospital. “Some patients are fragile enough that they may still succumb to this.”

Legionnaires’ disease is a type of pneumonia named after a severe outbreak that killed 34 people at a meeting of the American Legion in Philadelphia in 1976. The bacteria is typically found in the environment, usually in water.