Cases of a deadly lung disease have been reported this week in people who stayed at a luxury Las Vegas hotel.
Two guests of the Wynn Las Vegas hotel tested positive for legionnaire’s disease, a severe form of pneumonia spread through contaminated water vapor that kills one in 10 patients.
It is caused by a bacteria that thrives in warm, wet and moist environments.
The Southern Nevada Health District reported the cases on Tuesday. One person stayed at the hotel casino in September 2025 and the other more recently in February 2026.
After discovering the cases, the health district took samples from the Wynn Las Vegas and multiple samples tested positive for Legionella, the bacteria that causes legionnaires’ disease.
The health district said in response to the positive samples, the Wynn Las Vegas ‘initiated immediate and comprehensive water system remediation measures,’ though did not specify what the measures were.
Recent samples taken from the site ‘indicate no detectable levels’ of the bacteria and the hotel casino ‘has initiated direct guest notifications regarding potential exposure, and is implementing precautionary measures designed to mitigate any further risk of illness.’
Additionally, both individuals have since recovered, the agency added.
Several Las Vegas hotels are seen in the aerial view above, including the Wynn Las Vegas (left), where samples tested positive for Legionella, the bacteria that causes Legionnaires’ disease
News of the two Las Vegas cases comes shortly after North Carolina officials issued an alert earlier this month over a worrying rise of Legionnaires’ disease, as cases jumped 54 percent between 2024 and 2025.
The state saw 310 cases last year and has recorded 48 already in 2026.
In south Texas, officials in Ector County have also issued an alert over the bacteria after detecting 12 cases and two deaths between late December and early January.
And in Baltimore, Maryland, politicians have alleged the bacteria caused an outbreak this month at a federal building housing ICE detainees.
Nationwide, infections have soared over two decades, rising from 1,100 cases in 2000 to more than 8,000 today.
Health experts warn that warmer temperatures are allowing the bacteria to thrive in damp locations — including air conditioning units, hot tubs, water fountains and misting devices — raising the risk that it could cause an infection.
To avoid a Legionnaires’ infection, health officials urged people to clean and disinfect any water systems at home — including air conditioners, spray devices and others.
Advice included flushing faucets or shower heads that haven’t been used for three days or more, to deep clean hot tubs regularly and drain standing water from hoses.
Those with humidifiers and CPAP machines were urged to clean and replace filters regularly.
People over 50 years old, current or former smokers or those with lung conditions are most at risk from the disease.
Legionnaires’ disease is caused by the Legionella bacteria that thrives in moist and wet environments between 77 and 113 degrees Fahrenheit (25 to 45C).
People are see above in this file photo from the casino inside the Wynn Las Vegas
The bacteria may become airborne in steam or vapor and someone can become infected if they breathe in droplets.
Infected patients initially suffer from a headache, muscle aches, and fever that may be 104 Fahrenheit (40 Celsius) or higher.
But within three days, they may experience a cough, shortness of breath, chest pain, nausea, vomiting and diarrhea, and confusion or other mental changes.
In serious cases, patients can develop severe pneumonia, and the bacteria can spread to the blood, causing the potentially fatal complication sepsis. The bacteria can also infect the heart.
Patients die from the disease due to lung failure, septic shock, a sudden severe drop in blood flow to vital organs, or acute kidney failure, when these organs stop filtering waste from the blood.
Doctors treat the disease using antibiotics, but say these are most effective in the early stages before the disease has spread in the body. Patients are often hospitalized.
In milder cases, patients may also suffer from Pontiac fever, a condition causing fever, chills, headache and muscle aches that occurs when the bacteria do not infect the lungs. This condition goes away on its own without treatment and causes no further problems, doctors say.
