Six dead in Canadian Legionnaires disease outbreak

"We are very concerned by the current situation," Quebec public health chief Francois Desbiens said. "It's the largest legionellosis outbreak in Canada in recent years." Sixteen new cases were reported on Thursday alone. Health authorities suspect improper maintenance of cooling towers in air conditioning systems are at fault for the outbreak. Legionella bacteria grow in stagnant water in such appliances, then spread with droplets expelled by the system during operation.

http://www.telegraph.co.uk/news/worldnews/northamerica/canada/9496186/Six-dead-in-Canadian-Legionnaires-disease-outbreak.html