Legionnaires' Outbreak in New York

New York City is going through a terrible outbreak of Legionnaires' disease, the worst the city has ever seen.

Legionnaires' causes severe pneumonia, and got its name from an outbreak at an American Legion Convention in 1976 that killed 26 people. People get it by breathing in mist or water droplets that contain a bacteria called Legionella.

The bacteria live naturally in the environment, but thrive in warm standing water. That's when they cause trouble.

This time, they grew in cooling towers and spread to people through the air conditioning and ventilation systems.

The disease isn't spread from person to person, which is good news in a crowded city like New York.

The cooling towers have all been disinfected, but not before over 100 people became sick and some died.

Now, most people who are exposed to the bacteria won't get sick.

If they do, they'll go to the hospital.

But as long as they get antibiotics right away, they'll usually be just fine.

People who are over 50 years old, smoke, have chronic lung disease, or have a weakened immune system are more likely to catch it.

Most Legionnaires' cases can be traced to contaminated plumbing systems like public hot tubs, humidifiers, hot water tanks, and air conditioners.

Keeping those systems clean helps keep infections at bay.

But you don't need to worry about your conditioning and water system at home.

They're not known to cause it.

For WebMD, I'm Dr. Michael Smith.