Can You Get Legionnaires’ Disease from Drinking Water? A Deep Dive into the Risks

The short answer is rarely, but not impossible. While Legionnaires’ disease is primarily contracted through the inhalation of contaminated water droplets, the possibility of contracting it from drinking water exists, albeit significantly lower than from other sources like showers or cooling towers.

Understanding Legionnaires’ Disease

Legionnaires’ disease is a severe form of pneumonia caused by Legionella bacteria. These bacteria thrive in warm water environments, such as plumbing systems, cooling towers, and hot tubs. When Legionella contaminates water and is aerosolized, individuals can contract the disease by inhaling the contaminated mist. The disease manifests with symptoms like cough, shortness of breath, fever, muscle aches, and headaches. While treatable with antibiotics, Legionnaires’ disease can be fatal, especially in individuals with weakened immune systems or underlying health conditions.

The primary concern with Legionella lies in its ability to colonize in building water systems. Factors such as stagnant water, biofilm formation, and temperatures between 77°F (25°C) and 113°F (45°C) create an ideal breeding ground for the bacteria.

Why Drinking Water Poses a Lower Risk

While Legionella can be present in drinking water, the likelihood of infection through ingestion is considered relatively low. Several factors contribute to this reduced risk:

• Stomach Acid: The acidic environment of the stomach typically kills Legionella bacteria before they can establish an infection.
• Lower Bacterial Concentrations: The concentration of Legionella in drinking water is often lower than in aerosolized water droplets from sources like showers or cooling towers.
• Route of Entry: The primary route of infection is inhalation. Drinking water bypasses the lungs, reducing the opportunity for Legionella to directly infect the respiratory system.

However, certain situations can increase the risk of contracting Legionnaires’ disease from drinking water. Aspiration, where water is accidentally inhaled into the lungs during drinking, can bypass the stomach’s defenses and lead to infection. Individuals with swallowing difficulties or compromised immune systems may be more vulnerable.

Frequently Asked Questions (FAQs)

Here are some frequently asked questions about Legionnaires’ disease and its relationship to drinking water:

Is Legionella Present in All Drinking Water?

No, Legionella is not present in all drinking water. Public water systems are typically treated to control bacterial growth, including Legionella. However, the effectiveness of these treatments can vary, and Legionella can still colonize in building plumbing systems, particularly in older buildings with complex piping.

How is Drinking Water Treated to Prevent Legionella?

Municipal water treatment plants employ various methods to control Legionella, including:

• Disinfection: Chlorine, chloramine, and chlorine dioxide are commonly used disinfectants.
• Copper-Silver Ionization: This technology releases copper and silver ions into the water to inhibit bacterial growth.
• UV Disinfection: Ultraviolet light can effectively kill Legionella bacteria.

What are the Risk Factors for Legionnaires’ Disease?

Several factors increase the risk of contracting Legionnaires’ disease, including:

• Age: Individuals over 50 are at higher risk.
• Weakened Immune System: People with compromised immune systems due to illness or medication are more susceptible.
• Chronic Lung Disease: Individuals with COPD or other lung conditions are at increased risk.
• Smoking: Smoking weakens the respiratory system, making individuals more vulnerable to infection.
• Diabetes: People with diabetes have a higher risk.
• Underlying Health Conditions: Such as kidney disease.

Can Legionella Grow in My Home Plumbing?

Yes, Legionella can grow in home plumbing systems, especially if the water is not hot enough (below 140°F/60°C) or if there are areas of stagnation. Biofilm, a slimy layer of bacteria and other microorganisms, can also provide a protective environment for Legionella.

How Can I Prevent Legionella Growth in My Home Water System?

Several steps can be taken to prevent Legionella growth in your home water system:

• Maintain Water Heater Temperature: Set your water heater to 140°F (60°C) to kill Legionella. Be cautious about scalding and consider using mixing valves to temper the water at faucets and showers.
• Flush Stagnant Water: If you have been away for an extended period, flush all faucets and showers for several minutes to remove stagnant water.
• Clean Showerheads and Faucets: Regularly clean showerheads and faucet aerators to remove biofilm and mineral deposits.
• Insulate Pipes: Insulating hot water pipes can help maintain water temperature and prevent Legionella growth.

Are There Any Specific Situations Where Drinking Water Poses a Higher Risk?

Yes, certain situations can increase the risk:

• Aspiration: Accidentally inhaling water into the lungs while drinking.
• Water Fountains: Water fountains that are not properly maintained can harbor Legionella.
• Ice Machines: Ice machines can become contaminated with Legionella if not cleaned and disinfected regularly.

Should I Be Concerned About Legionella in My Water if I Have a Well?

Well water can be susceptible to Legionella contamination. Regular testing and disinfection are crucial to ensure the safety of your well water. Contact your local health department for guidance on well water testing and treatment.

How Do I Know if My Water is Contaminated with Legionella?

Legionella is invisible to the naked eye and has no taste or odor. The only way to determine if your water is contaminated is through laboratory testing.

Where Can I Get My Water Tested for Legionella?

Contact your local health department or a certified environmental testing laboratory. They can provide information on sample collection procedures and testing costs.

What is the Treatment for Legionnaires’ Disease?

Legionnaires’ disease is treated with antibiotics. Early diagnosis and treatment are crucial to prevent severe complications.

Are Cooling Towers the Only Source of Legionella Exposure?

No, while cooling towers are a well-known source, Legionella can also be found in:

• Showers and faucets
• Hot tubs and spas
• Decorative fountains
• Humidifiers
• Large plumbing systems

What Regulations Exist to Control Legionella in Buildings?

Many states and municipalities have regulations and guidelines for Legionella control in buildings, particularly in healthcare facilities and large buildings with complex water systems. These regulations often require regular water testing, risk assessments, and water management plans. ASHRAE Standard 188 provides guidelines for developing and implementing effective water management plans to minimize the risk of Legionella growth.

Conclusion

While the risk of contracting Legionnaires’ disease from drinking water is generally low, it’s essential to understand the factors that can increase the risk and take preventative measures to protect yourself and your family. Maintaining proper water temperatures, flushing stagnant water, and regularly cleaning plumbing fixtures can help minimize Legionella growth in your home water system. For further information and guidance, consult with your local health department or a qualified water treatment professional.