Hotel Service Unit 12 Q3

Legionella bacteria are a type of bacteria that can cause Legionnaires’ disease, a severe form of pneumonia (lung infection), and a milder illness called Pontiac fever.  

1. Legionella (Legionnaires’ Disease and Pontiac Fever) – CDC

Key Points about Legionella:

• Habitat: Legionella bacteria thrive in warm water environments, such as:
  • Cooling towers   1. Controlling Legionella in Cooling Towers – CDC www.cdc.gov
  • Hot tubs and spas   1. About Protecting Yourself from Legionella in Hot Tubs | Healthy Swimming – CDC www.cdc.gov
  • Hot water tanks and heaters
  • Decorative fountains   1. Hidden dangers in ornamental water features – Metro Safety www.metrosafety.co.uk
  • Plumbing systems in large buildings   1. Legionella Prevention: A Priority in Plumbing System Design – phcppros www.phcppros.com
    1. Environments That Legionella Bacteria Develops – Tower Water www.towerwater.com
• Transmission: People can get Legionnaires’ disease by inhaling small droplets of water containing Legionella bacteria. These droplets can become aerosolized and spread through the air from contaminated water sources. Person-to-person transmission is rare.   1. About Legionnaires’ Disease | Legionella – CDC www.cdc.gov2. How Legionella Spreads – CDC www.cdc.gov
• Symptoms: Symptoms of Legionnaires’ disease include:
  • Cough   1. Legionnaires’ disease (legionellosis) – Info.health.nz info.health.nz
  • Shortness of breath   1. Legionnaires’ disease – NHS www.nhs.uk
  • Fever   1. About Legionnaires’ Disease | Legionella – CDC www.cdc.gov
  • Muscle aches   1. Legionnaires’ disease – Symptoms and treatment – HSE www.hse.gov.uk
  • Headaches   1. Legionnaires’ disease – Symptoms & causes – Mayo Clinic www.mayoclinic.org
  • Confusion   1. Legionnaires’ disease – Symptoms and treatment – HSE www.hse.gov.uk
• Risk Factors: People at higher risk of Legionnaires’ disease include:
  • Older adults (50 years or older)   1. Facts about Legionnaires’ disease www.ecdc.europa.eu
  • Smokers   1. How Legionella Spreads – CDC www.cdc.gov
  • People with weakened immune systems   1. What is Legionnaires’ disease? – HSE www.hse.gov.uk
  • People with chronic lung disease   1. What is Legionnaires’ disease? – HSE www.hse.gov.uk

Prevention:

• Controlling Legionella Growth: The primary way to prevent Legionnaires’ disease is to control the growth and spread of Legionella bacteria in water systems. This can be done through regular cleaning and disinfection, maintaining proper water temperatures, and avoiding stagnant water.   1. About Legionnaires’ Disease | Legionella – CDC www.cdc.gov
• Marine Air Conditioning Systems: On ships, air conditioning systems can be a potential source of Legionella. Regular maintenance, cleaning, and disinfection of these systems are critical for preventing the growth and spread of the bacteria.   1. Legionella in Air Conditioning Systems: Can Legionella Spread Through AC? – Robinsons Facilities Services www.robinsonsfs.com2. Legionellosis (Legionnaires’ Disease and Pontiac Fever) – Control Prevention | Occupational Safety and Health Administration www.osha.gov

If you are concerned about Legionella bacteria on your vessel, consult with a qualified marine engineer or environmental health specialist to assess the risks and implement appropriate control measures.

On a superyacht, the main areas that are considered to be breeding grounds for Legionella bacteria include:

1. Water Systems:

• Hot Water Tanks and Heaters: These provide a warm environment ideal for Legionella growth if the water temperature is not maintained above 60°C (140°F).
• Showerheads and Faucets: Stagnant water within showerheads and faucets, especially those infrequently used, can harbor Legionella.
• Whirlpool Spas and Jacuzzis: The combination of warm water and aeration in these systems creates favorable conditions for bacterial growth.
• Decorative Fountains and Water Features: Stagnant water in these features can also become breeding grounds for Legionella.
• Plumbing Systems: Complex plumbing systems with dead legs (sections with little or no water flow) or biofilm accumulation can provide niches for Legionella colonization.

2. Air Conditioning Systems:

• Cooling Towers: These are prime breeding grounds for Legionella due to their warm water and aerosolization potential.
• Humidifiers: Particularly those using water spray systems, can aerosolize Legionella-contaminated water droplets into the air.
• Air Handling Units and Ductwork: Stagnant water or condensation within these components can create conditions for Legionella growth.

3. Other Areas:

• Swimming Pools and Spas: Although chlorinated pools are generally less susceptible, improper maintenance or low chlorine levels can lead to Legionella growth.
• Water Storage Tanks: Infrequent use or inadequate cleaning of tanks can lead to stagnant water and potential Legionella contamination.
• Ornamental Ponds or Water Features: Any stagnant water features on the yacht can potentially harbor the bacteria.

Factors Increasing the Risk:

• Warm Water Temperatures: Legionella bacteria thrive in temperatures between 20°C and 45°C (68°F to 113°F).
• Stagnant Water: Water that is not circulating or regularly flushed provides a breeding ground for bacteria.
• Presence of Biofilms: Biofilms, which are slimy layers formed by bacteria, can provide a protective environment for Legionella and make it more difficult to disinfect.
• Aerosol Generation: Systems that create aerosols, such as showerheads, humidifiers, and cooling towers, can spread Legionella-contaminated water droplets into the air, increasing the risk of inhalation.

It’s crucial to note that while these are the main areas of concern, any water system on a superyacht can potentially harbor Legionella if not properly maintained and disinfected. Regular inspections, cleaning, and water treatment are essential for preventing Legionella growth and protecting the health of everyone onboard.