Bill de Blasio, New York City Mayor, had demanded a citywide inspection of water-cooling towers after these were determined to be key cause behind the outbreak of Legionnaires' disease in the city's South Bronx neighborhood.

Bronx outbreak has been said to be largest outbreak of the bacterial infection in New York City’s history and one of the biggest in the U.S. in recent years. City health-department officials stated that the diseases was likely spread by mist emitted by cooling towers, majorly used to air-condition larger, more modern buildings.

The disease causes pneumonia-like symptoms, but doesn’t spread from person to person, they added. It has been told that five water-cooling towers in the South Bronx tested positive for legionella bacteria.

Dr. Preeta Kutty, a medical epidemiologist at the Centers for Disease Control and Prevention, said in a statement that the New York outbreak is one of the largest the country has seen in the past decade and is notable because it affects a community, not just one building.

City healthy officials said nearly 10% of the reported cases occurred in people with HIV. Other conditions common to people infected lung disease, diabetes and chronic use of alcohol or cigarettes.

As per CDC estimates, every year nearly 8,000 to 18,000 people in the U.S. are hospitalized with Legionnaires’, the data includes the unreported cases as well.

Ohio had the most reported cases in the country last year, followed by New York and Pennsylvania, revealed data.

Legionella, is ubiquitous, although it is extremely unlikely for healthy people to contract the disease, said Dr. Sebastien Faucher, a microbiologist at McGill University.