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Legionnaires Disease
Urgent
Legionnaires disease is a serious form of pneumonia caused by Legionella bacteria. Infection usually occurs when a person breathes contaminated water droplets or mist from systems in which the bacteria have multiplied. Symptoms can include fever, cough, shortness of breath, muscle aches, headache, and fatigue, and some people may also develop gastrointestinal symptoms. The illness can become severe, particularly in older adults and people with chronic diseases or weakened immune systems.
Body System
Respiratory System
When to Seek Medical Attention
Legionnaires disease requires prompt medical assessment and appropriate treatment because it can cause severe pneumonia and systemic illness. Seek urgent care for high fever, worsening cough, shortness of breath, confusion, gastrointestinal symptoms, or significant weakness. Emergency assessment is needed for severe breathing difficulty, confusion, fainting, bluish lips or skin, severe dehydration, or rapidly worsening illness.
Symptoms
4
Causes
1
Treatments
5
Diet
3
Overview
Legionnaires disease is a serious form of pneumonia caused by Legionella bacteria. Infection usually occurs when a person breathes contaminated water droplets or mist from systems in which the bacteria have multiplied. Symptoms can include fever, cough, shortness of breath, muscle aches, headache, and fatigue, and some people may also develop gastrointestinal symptoms. The illness can become severe, particularly in older adults and people with chronic diseases or weakened immune systems.
Symptoms 4
Chest Pain
Diarrhea
Dry Cough
Fever
Causes 1
Legionnaires disease is caused mainly by Legionella pneumophila and related Legionella bacteria. These organisms can multiply in water systems when temperature, stagnant water, inadequate disinfection, and other environmental conditions allow bacterial growth. Infection generally occurs after inhaling contaminated water droplets or mist from showers, cooling systems, hot tubs, fountains, or other water-containing equipment. Person-to-person transmission is uncommon, and most infections are associated with environmental exposure.
Infection
Risk Factors
Risk is higher in people over 50 years of age, current or former smokers, and people with chronic lung disease, diabetes, kidney disease, cancer, or weakened immunity. Recent hospitalization and residence in long-term care facilities can increase exposure opportunities. The risk of disease is also influenced by exposure to contaminated water systems, cooling equipment, hot tubs, or other environments where Legionella bacteria can multiply.
Diagnosis
Diagnosis is based on a patient's medical history,
symptoms, physical examination and, when necessary,
laboratory or imaging investigations.
Diagnosis generally involves evaluation of pneumonia together with testing specifically directed at Legionella when the clinical situation warrants it. Chest imaging can demonstrate pneumonia, while laboratory testing may include a urinary antigen test and testing of respiratory specimens by culture or molecular methods. The choice of testing depends on illness severity, exposure history, local public health considerations, and whether an outbreak or healthcare-associated exposure is suspected.
Prevention
Key Prevention Tips
Prevention focuses on controlling Legionella growth in water systems
Building owners and facility managers should maintain and disinfect plumbing systems, cooling equipment, hot tubs, and other water systems according to appropriate safety procedures
Avoiding conditions that allow stagnant water and bacterial growth can reduce contamination
During recognized outbreaks or exposures, people at increased risk should follow public health recommendations
Healthcare facilities and long-term care settings should maintain appropriate water-management programs
Prevention Guidance
Prevention focuses on controlling Legionella growth in water systems. Building owners and facility managers should maintain and disinfect plumbing systems, cooling equipment, hot tubs, and other water systems according to appropriate safety procedures. Avoiding conditions that allow stagnant water and bacterial growth can reduce contamination. During recognized outbreaks or exposures, people at increased risk should follow public health recommendations. Healthcare facilities and long-term care settings should maintain appropriate water-management programs.
Reminder: Prevention recommendations should be tailored to your personal health status and risk factors.
Treatment & Management 5
Detailed treatment guidance is currently being prepared.
Detailed treatment guidance is currently being prepared.
Detailed treatment guidance is currently being prepared.
Detailed treatment guidance is currently being prepared.
Detailed treatment guidance is currently being prepared.
Medical Note: The treatment information provided is intended for educational purposes only.
Always consult a qualified healthcare professional before starting,
stopping, or changing any treatment.
Diet & Nutrition 3
Recommended Foods
Warm Soups
Support hydration and recovery.
Protein Rich Foods
Help maintain strength.
Fresh Fruits
Provide vitamins and antioxidants.
Foods to Avoid
Alcohol
May worsen dehydration.
Junk Food
Provides poor nutrition.
Medical Nutrition Note: Diet recommendations are intended for general educational purposes and should be tailored to individual health needs by a qualified healthcare professional.
Frequently Asked Questions 5
It is a severe type of pneumonia caused by Legionella bacteria.
It spreads through inhalation of contaminated water droplets.
Fever, cough and breathing difficulty are common.
Urine antigen tests and respiratory samples help diagnosis.
Proper maintenance of water systems helps prevention.
Helpful Tip: These answers provide general medical information.
Consult your healthcare provider for advice tailored to your condition.