QUEBEC CITY -- The city's medical authorities confirmed Sunday that an 11th person has died from the outbreak of Legionnaires' disease that began in July.

Authorities reported five more cases since Saturday, bringing the total number of people infected to 169 since mid-summer.

Francois Desbiens, the head of Quebec City's public health agency, said the five became infected between 10 and 15 days ago.

"The incubation period of this disease is two to 10 days," he said.

Legionnaires' disease can cause a severe pneumonia-like condition, a high fever and bloody coughing spells and usually affects those who are middle-aged or older.

The government said the outbreak likely started inside poorly maintained cooling systems atop Quebec City buildings. Legionnaires' bacteria begin to spread in temperatures between 25-42 degrees Celsius. The bacteria naturally occur in water and humid soil.

The elderly and those with chronic illnesses are some of the groups most at-risk for contracting Legionnaires.
The disease is transmitted through the air from contaminated water particles that are inhaled.

Legionnaires' disease can not be transmitted from one person to another, according to Quebec's public health agency.

Quebec City medical authorities are expected to hold a news conference on Sunday to provide an update on the outbreak.