Nevada health officials investigate cluster of Legionnaires' disease linked to Vegas hotels

A minor cluster of Legionnaires' disease cases among guests who stayed at two Las Vegas hotels are being investigated by Nevada health officials.

Legionnaires' disease is a type of pneumonia that is caused by legionella bacteria. Two guests were diagnosed after staying at Caesars Palace Hotel and Casino within the last year, according to the Southern Nevada Health District.

A guest at The Orleans Hotel & Casino was also found to have the disease, according to a different release on Thursday.

Both hotels are cooperating with the health officials' investigations. 

Caesars Palace Hotel and Casino completed its water system remediation and the tests didn't detect legionella bacteria, according to NBC News.

The Southern Nevada Health District warned that people most at risk for this disease include those above 50, smokers and people with weak immune systems.

"Guests who stayed at Caesars Palace more than two weeks ago and have not developed symptoms are not at risk for disease," the health district said in a statement. "If guests of the property develop symptoms within 14 days of their stay, they should seek medical attention and alert their medical provider of the potential exposure."