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175 Healthcare: Biological Hazards
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Legionnaires' disease

Legionnaires' disease is a severe form of pneumonia, requiring treatment with antibiotics to kill the harmful Legionella bacteria in the lungs. It is commonly associated with water-based aerosols and often a result of poorly maintained air conditioning cooling towers and potable water systems. It occurs where water, contaminated with the legionella organism, is aerosolized and then breathed in by workers or patients. Legionnaires' disease is not contagious but is a potential environmental hazard. Consequently, only those who are directly exposed to a contaminated aerosolized water source can get the disease.

Legionnaires' disease is a bacterial disease commonly associated with water-based aerosols.

Healthcare facilities often have large, complex building water systems. They frequently undergo construction and plumbing changes. They often have aerosol-producing devices, like cooling towers, decorative fountains, and other devices unique to healthcare facilities (e.g., respiratory therapy equipment, hydrotherapy tubs, heater-cooler units). Patients in these settings often have risk factors for Legionnaires’ disease, such as advanced age, weakened immune systems, and chronic medical conditions.

Most cases of this illness can be treated successfully. Healthy people usually get better after being sick with Legionnaires’ disease, but they often need care in the hospital.

Symptoms

Legionnaires' disease usually develops two to 10 days after exposure to legionella bacteria. It frequently begins with the following signs and symptoms:

  • headache
  • muscle aches
  • fever that may be 104°F (40°C) or higher
Legionnaires' disease usually develops two to 10 days after exposure to legionella bacteria.

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

  • cough, which might bring up mucus and sometimes blood
  • shortness of breath
  • chest pain
  • 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.

Possible complications of Legionnaires' disease include:

  • respiratory failure
  • septic shock
  • kidney failure

When not treated promptly, Legionnaires' disease can lead to death. About 1 out of every 10 people who gets sick with Legionnaires' disease will die due to complications from their illness. For those who get Legionnaires' disease during a stay in a healthcare facility, about 1 out of every 4 will die.

Knowledge Check Choose the best answer for the question.

1-3. Only those who are _____ exposed to a contaminated aerosolized water source can get Legionnaires' disease.