Nevada health officials are investigating a small cluster of Legionnaires’ disease cases among guests who stayed at two Las Vegas hotels.
Two people have been diagnosed with Legionnaires’ disease — a severe form of pneumonia caused by Legionella bacteria — after staying at Caesars Palace Hotel and Casino in the past 12 months, the Southern Nevada Health District announced Thursday.
A guest at the Orleans Hotel & Casino was also recently diagnosed with the disease, the health district said in a separate statement Thursday. Earlier this year, two cases of legionnaires were reported among guests at Orleans, prompting an investigation.
After these first two cases, the hotel’s water system was sanitized, and subsequent tests failed to detect Legionella bacteria, according to the health ministry. But after the new case was reported, environmental samples tested positive for Legionella. The Orleans Hotel & Casino is therefore once again carrying out sanitation tests and environmental tests to ensure the elimination of the bacteria.
Both properties are cooperating with health district investigations.
The Caesars Palace Hotel and Casino has already completed sanitizing its water system and the most recent environmental tests did not detect legionella bacteria, according to the Department of Health.
The ministry did not immediately respond to a request for additional information.
Legionella bacteria exist naturally in freshwater bodies, but can pose a threat to humans when they grow and spread in building water systems like cooling towers or water tanks, according to the Centers for Disease Control and Prevention.
The bacteria can spread as droplets small enough to inhale, but most healthy people exposed don’t get sick, according to the CDC.
Symptoms of Legionnaires’ disease include cough, shortness of breath, fever, muscle aches and headaches and usually begin two to 14 days after exposure. As with other forms of pneumonia, the disease can lead to serious complications or be fatal if not treated quickly.
People at increased risk of disease include people aged 50 and over, who smoke or have been smokers, who have chronic lung disease or a weakened immune system, who take medications that may weaken their immune system or suffer from underlying diseases.
The health department said guests who have stayed at either property since August 1 and show symptoms up to 14 days after their stay can report their illness using an online form.