Interestedly following the legionnaire's disease outbreak in Quebec and am suddenly confused. The disease has been identified at multiple, independant, locations around Quebec. However it has not caused an outbreak in 10 years. If it has not been present until this year, how did it infect multiple sites? If it has been present all over the place, how did it not infect people before this? What changed?

I'm genuinely confused, has anyone come across an explanation to these questions?