Health officials identified Legionnaire's disease (search) Thursday as the illness that killed 16 elderly people at a Toronto nursing home, a medical officer said.
There have been no new deaths and the spread of the illness has been contained, said David McKeown of Toronto's health department.
"Some people are fragile enough that they may still succumb to this," McKeown said at a briefing that included Toronto Mayor David Miller and Dr. Donald Low, medical director of Ontario's Public Health Laboratories.
Health experts, including the World Health Organization (search), earlier insisted the illness is winding down and emphasized it has been contained to the Seven Oaks Home for the Aged in the eastern suburbs of Toronto.
Their inability to at first identify it spooked the elderly and cast a shadow over a city still trying to shed bad publicity from the SARS (search) epidemic.
Provincial and city officials are concerned over the growing international media coverage of the mystery bug, worried tourists will flock from Canada's largest city, as they did during the SARS outbreak in the spring of 2003.
Legionnaires' disease is a type of pneumonia named after a severe outbreak that affected a meeting of the American Legion in Philadelphia in 1976.
In the United States, an estimated 8,000-18,000 cases occur each year, but only a fraction of these are reported, officials say.