New Delhi, Aug. 5 -- A deadly outbreak of Legionnaires' disease has infected 58 people and killed two, health officials confirmed. The illness, caused by Legionella bacteria, spreads through contaminated water systems like cooling towers, hot tubs, and plumbing.

This mirrors recent clusters in New York City where 1 died and 22 fell ill after exposure to contaminated aerosols in Harlem . The bacteria thrive in warm water (20deg-50degC/68deg-122degF) and enter the lungs when people inhale mist or vapor from infected sources.

Though not contagious between people, it can cause severe pneumonia. The disease was first identified in 1976 after an American Legion convention outbreak in Philadelphia, where 29 attendees died.

Legionnaires' strik...