Where Legionella hides (and what to do about it)

Understanding Legionella and Legionnaires' Disease

Legionella is a type of bacteria that can cause serious illnesses, including Legionnaires' disease and Pontiac fever.

It thrives in man-made water systems like AC cooling towers, hot tubs, and plumbing systems in large buildings. This bacteria is a major health risk, especially among people with compromised immune systems.

2 Types of Illnesses Caused by Legionella

Legionnaires' Disease

  • Symptoms: High fever, cough, shortness of breath, muscle aches, headaches, and sometimes diarrhea and confusion.

  • How it Spreads: By inhaling small droplets of water contaminated with Legionella bacteria.

  • Who is at Risk: Older adults, smokers, people with chronic lung diseases, and individuals with weakened immune systems.

  • Treatment: Typically treated with antibiotics like macrolides (azithromycin) or fluoroquinolones (levofloxacin).

Pontiac Fever

  • Symptoms: Flu-like symptoms, including fever, headache, and muscle aches, without causing pneumonia.

  • Difference from Legionnaires' Disease: Milder and self-resolving, usually without the need for medical treatment.

Sources of Legionella

Legionella bacteria can be found in water systems, particularly those that are not properly maintained. Common sources include:

Cooling Towers: Part of air conditioning systems for large buildings.

Hot Tubs and Spas: Especially if they are not cleaned and disinfected regularly.

Plumbing Systems: In large buildings, where water can stagnate and bacteria can grow.

Hot Water Tanks and Heaters: Particularly if the temperature is not maintained correctly.

Decorative Fountains: Can aerosolize contaminated water.

Prevention and Control

Tips for Homeowners

  • Regularly clean and disinfect hot tubs.

  • Maintain water heaters at temperatures above 60°C (140°F).

  • Flush unused water fixtures regularly.

Recommendations for Building Managers

  • Implement regular maintenance and cleaning schedules.

  • Use water treatment methods to control bacterial growth.

  • Regularly monitor and test water systems for Legionella.

Recognizing and Responding to an Outbreak

Signs of an Outbreak:

Sudden onset of Legionnaires' disease symptoms in multiple individuals associated with the same location.

Steps to Take:

  • Contact local health authorities immediately.

  • Implement emergency disinfection procedures.

  • Inform potentially affected individuals and provide guidance on seeking medical care.

Frequently Asked Questions (FAQs)

Can Legionnaires' disease be spread from person to person?

No, Legionnaires' disease cannot be spread from person to person. It is contracted by inhaling contaminated water droplets.

How common is Legionnaires' disease?

While it is not extremely common, cases have been increasing in recent years. It is important to maintain water systems properly to prevent outbreaks.

What should I do if I think I've been exposed?

If you develop symptoms of Legionnaires' disease, such as fever, cough, or shortness of breath, contact your healthcare provider immediately.