Infectious Diseases
Legionnaires' Disease — Causes, Symptoms, and Prevention
2025-08-28
Legionnaires’ disease is a severe pneumonia caused by Legionella bacteria. People get sick by inhaling tiny water droplets containing the bacteria — not from drinking water and not from person-to-person spread (extremely rare). Outbreaks often trace back to poorly maintained water systems.
How infection happens
- Aerosolized water from cooling towers, decorative fountains, showers, hot tubs/spas, humidifiers, or complex plumbing.
- Bacteria thrive in stagnant, warm water (20–45°C / 68–113°F), biofilms, and scale.
Symptoms & timing
- Starts 2–10 days after exposure (occasionally up to 14 days).
- High fever, chills, cough (dry or productive), shortness of breath, chest pain.
- Often includes headache, muscle aches, fatigue, and sometimes diarrhea or confusion.
Who is most at risk
- Age 50+, smokers, people with chronic lung disease, diabetes, kidney disease, cancer, or weakened immunity.
- Recent hotel/cruise stays, hospitalization, or buildings with complex water systems.
Prevention — practical steps
- Prefer well-maintained accommodations; look for good hygiene standards.
- Avoid or limit time near steamy hot tubs or decorative fountains in unclear maintenance settings.
- In rooms unused for a while, run the shower hot for a few minutes with the door closed before use.
- Facility owners should follow water safety plans (regular flushing, temperature control, biocide, sediment control).
When to seek medical care
- Pneumonia symptoms (fever, cough, shortness of breath), especially after hotel/spa/cruise or healthcare exposure.
- Tell clinicians about recent travel or exposure to water systems; this helps trigger Legionella testing.
- Early diagnosis and appropriate antibiotics improve outcomes.
This guide is for general information and isn’t a substitute for professional medical advice. Seek emergency care for severe breathing difficulty, confusion, or chest pain.
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- #legionella
- #pneumonia
- #travel
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