Legionnaires' disease shook the luxurious Aria Resort and Casino on the Las Vegas Strip.

Six guests who stayed at the resort between June 21 and July 4 were found to be infected by the disease.

The total number of guests affected by the legionnaire's disease outbreak is still unkown.

The instances were reported to the

Legionnaire's disease is a deadly form of pneumonia [SEE BELOW FOR SYMPTOMS]. Failing to see a doctor early could cause sufferers their lives.

It is caused by a water-borne bacteria called legionella.

Human beings and the bacteria that may result in legionnaire's disease and kill them have one thing in common:   

Legionella is a bacteria that lives in water and loves warm, wet environments, Dr. Mary Nettleman, head of the medicine at Michigan State University, told ABC news. Unfortunately, people also like warm, wet environments, like hot tubs.

Air-conditioning and hot tubs are potential breeding grounds for the disease according to experts.

Water tests at the Aria hotel detected high levels of Legionella during the time period between July 21 and July 4.

If you are worried that you or someone you know may have Legionnaire's Disease, here is more information from the Mayo Clinic:

Symptoms of Legionnaire's Disease

Legionnaires' disease usually develops two to 14 days after exposure to legionella bacteria. It frequently begins with the following signs and symptoms:

  • Headache
  • Muscle pain
  • Chills
  • Fever that may be 104 F (40 C) or higher

By the second or third day, you'll develop other signs and symptoms that may include:

  • Cough, which may bring up mucus and sometimes blood
  • Shortness of breath
  • Chest pain
  • Fatigue
  • Loss of appetite
  • Gastrointestinal symptoms, such as nausea, vomiting and diarrhea
  • Confusion or other mental changes

Although Legionnaires' disease primarily affects the lungs, it occasionally can cause infections in wounds and in other parts of the body, including the heart.

A mild form of Legionnaires' disease - known as Pontiac fever - may produce symptoms including fever, chills, headache and muscle aches. Pontiac fever doesn't infect your lungs, and symptoms usually clear within two to five days.

When to see a doctor
See your doctor if you think you've been exposed to legionella bacteria. Be sure to mention any trips you've taken in the past two weeks and where you stayed. Diagnosing and treating Legionnaires' disease as soon as possible can help shorten the recovery period and prevent serious complications. For people at high risk, prompt treatment is critical.