More than 70 people have been hospitalised and 2 people have died from a Legionnaires' outbreak in Melbourne's West.

It's the largest outbreak in the country since 2000, when 125 people were infected at the Melbourne Aquarium.

Dawn and Cheryl share what it's like to go through that illness and its aftermath. And Professor Elizabeth Hartland explains what science tells us about the infection and the safety mechanisms currently in place.