 -- Health officials said the Legionnaire’s disease outbreak in New York City that led to 86 people infected and 7 deaths has likely already reached its peak and that cases will likely decline in the upcoming weeks.

While health officials hope the outbreak is dwindling, the large number of those infected prompted New York City Mayor Bill de Blasio to plan new legislation aimed at cutting down future outbreaks.

The New York City Health Department reported that the all those who died had underlying medical problems and were older adults. Of those infected at least 64 had to be hospitalized.

The disease is caused by Legionnella bacteria and is spread through water droplets that are inhaled. It can be spread through fountains, shower heads, pools or air conditioning cooling towers. Symptoms include fever, coughing and shortness of breath.

Currently, five cooling towers in the South Bronx have tested positive for legionella bacteria. In those cases, the air inside the building isn’t generally affected, instead it the air conditioners let off cooling mist from the top of the building which then can infect people passing by the area. Health officials said today that the contaminated towers had been cleaned and flushed to remove all bacteria.

In a press conference today Mayor Bill de Blasio said that health officials believe one of the towers is the source of the outbreak.

"The five sites we have found, we’re confident based on scientific evidence we have identified only sites that are causing this outbreak," he told reporters. He said more testing would need to be done to confirm the towers were the source of the outbreka.

Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical School, said the large outbreak is concerning as health officials still don’t know specifically what the source of the outbreak is and how everyone infected was exposed.

“Are their clusters of association…at a house of worship at this, that or the other function?” said Schaffner. “This is an extraordinary cluster, why in the Bronx and not in Brooklyn or Manhattan for example.”

While cooling towers have tested positive for the bacteria, Dr. Stephen Morse, an infectious disease expert at the Columbia University Mailman School of Public Health, explained the bacteria is naturally occurring in the environment.

“What surprises me more is that we don’t see it more often, it’s common in cooling towers or central air conditioning systems,” he said. “You’re going to find it in a lot of places where there are no reports of people being sick.”

To stop the outbreak the New York City Health Department is taking steps including talking to doctors, reaching out to community leaders and attempting to match the bacteria making patients sick with the bacteria found in various cooling units. New York City Mayor Bill DeBlasio said in a statement he would introduce legislation designed to cut down on Legionnaire’s disease outbreaks.

“The comprehensive package will address inspections, new recommended action in the case of positive tests, and sanctions for those who fail to comply with new standards,” de Blasio said in a statement. “Legionnaires’ Disease outbreaks have become far too common over the past ten years.”

Summer and fall are when more cases of Legionnaire’s disease are diagnosed according to the U.S. Centers for Disease Control and Prevention. New York is not the only state grappling with the disease. In Michigan a woman reportedly died suddenly after contracting the bacterial disease.