An outbreak of legionnaires' disease that has killed six people in Quebec City is all the more tragic because a report 15 years ago suggested ways to prevent it but was ignored, Mayor Régis Labeaume said Friday.

Labeaume, who cut short his vacation to respond to the outbreak, told a news conference he's "indignant at the indifference" and is calling on Quebec's political parties to commit to enact legislation as soon as possible.

He said he's spoken to Premier Jean Charest and Health Minister Yves Bolduc, who has a news conference scheduled for Friday afternoon, and is anticipating imminent action. If another party comes to power in the Sept. 4 provincial election, Labeaume said, he would press it to do something immediately.

"I don't want to go on a witchunt, but it's clear that indifference toward the 1997 report is a bit disappointing," the mayor said, calling the six deaths six too many.

"Since 1997, nothing has been done to fix this situation.... We will do everyting to make sure this doesn't happen again, because we will and have asked for concrete measures from the parties hoping to be the next government of Quebec."

The 1997 report, which came in the wake of Quebec City's previous outbreak of legionnaires' disease, recommended the province create a registry of buildings that use cooling towers in their ventilation systems, so that an outbreak could be more quickly isolated. It also recommended tougher regulations for inspecting and maintaining the towers, which are typically installed on rooftops as one of several ways to keep a building's air fresh and control its temperature.

Legionnaires, a flu-like pneumonia that usually only sickens people with lung problems or weak immune systems, is caused by bacteria that thrive in warm temperatures and can breed in the stagnant water of such cooling towers, before spreading in the mist released by those systems.

Without a list of rooftop cooling towers in the area, Quebec City inspectors had to go up a skyscraper to look out over the surrounding area and visually tally them, a process that delayed their efforts to contain the outbreak.

Quebec City's regional public health authority said Friday there have been no new cases discovered since the day before, when it announced the two latest deaths as well as new infections, bringing the total number of cases to 81.

The health authority had said it was the most severe legionnaires' outbreak in Canada in 20 years, but there have been worse: A 2005 outbreak at a nursing home in Toronto caused 21 deaths and made 127 people sick.

New infections in Quebec City are now highly unlikely because inspectors deployed this week to check every cooling tower in the downtown area — where officials are almost certain the outbreak stems from — and they delivered a "shock treatment" of bromine to kill any bacteria. They also sampled the water in the 62 towers, though it will take three to four weeks for test results to isolate exactly which building is the source.

It is possible new cases will emerge over the next days, however, because the disease has an incubation period.

"Everyone needs to know that we've got the situation under control," Mayor Labeaume said Friday. He was particularly adamant that people have nothing to worry about from a Madonna concert next Saturday, Sept. 1, on the Plains of Abraham, nor Sunday's Laval University football game, because legionnaires' disease cannot be passed between people.

"You cannot transmit it to someone else. So if you have the bacteria and you go to the show of Madonna, you cannot transmit it to 70,000 people."Labeaume also said the onus lies on the province to enact regulations on cooling towers because the spread of legionnaires' disease doesn't respect municipal boundaries. The scientific literature has found cases where the bacteria have travelled more than two kilometres in mist, which the mayor said means it can cross into a city from a neighbouring jurisdiction.