The Connection Between Lockdowns and Legionnaires

Reopening buildings safely and maintaining a healthy indoor environment may be more challenging than many administrators anticipate. By late 2020, the detection of Legionella had already caused major issues at several schools in Ohio and Pennsylvania. 

Legionnaires’ disease, the disease caused by Legionella pneumophila bacteria, can lead to long-term health issues. The conditions in building water systems are ideal for the growth of Legionella, and reopening buildings safely requires due consideration to prevent the further spread of the disease. 


Key Takeaways:

  • Legionella bacteria cause Legionnaires’ disease and can grow in building water systems
  • During extended lockdowns and low occupancy, the risk of Legionella growth increases exponentially
  • To reopen buildings safely, you’ll need a re-occupancy plan that addresses all the elevated risks from Legionella growth

Lockdowns and Legionnaires – What You Should Know

Legionellaceae is a family of bacteria with over 40 species of which about half can cause Legionnaires’ disease. Approximately 90% of these infections come from the Legionella pneumophila species. According to Mayo Clinic, symptoms may develop between two and 10 days after exposure. 


What are the Symptoms and Health Effects of Legionnaires?

After infection, patients may develop flu-like symptoms. Although the disease primarily infects the lungs, in some cases it can affect the heart or infect wounds. 


The symptoms of Legionnaires’ disease include:

  • Fever, headaches, and muscle pain (early symptoms)
  • Chest pains, shortness of breath, coughing, nausea, vomiting, and diarrhea
  • Mental fatigue and confusion

If not treated early, Legionnaires’ disease can lead to:

  • Long-term fatigue
  • Neuromuscular and neurologic symptoms
  • Reduced quality of life and posttraumatic stress disorder

The diagram below shows the typical lifecycle of a Legionella infection. 

Typical lifecycle of a Legionella infection in human patients



How Does Legionella Spread in Water Systems?

Legionella lives in natural environments but can multiply in building water systems under certain conditions. Hotels, schools, hospitals, and other large buildings where water can stagnate in the plumbing can lead to large colonies of Legionella bacteria developing. 

During lockdowns, the extended shutdown of these buildings may cause elevated risks of Legionella outbreaks if the administrators don’t carefully plan the return to service of water systems. 



How to Safely Reopen Buildings after Extended Shutdowns

The build-up of Legionella in stagnant water systems after extended shutdowns is a major concern for building administrators and managers. Stagnant water and lower temperatures provide the ideal conditions for biofilm-based bacterial growth.


Even under normal operating conditions, building managers need to take precautions to prevent Legionella from forming in any area of the building’s water systems. After an extended shutdown, the risk of Legionella increases exponentially. To reopen the building safely, you’ll need a return-to-service and re-occupancy plan that addresses these issues. 


How Does Legionella Infect People from Water Systems?

Once a colony of Legionella exists in a building’s piping systems, all points of contact and outlets may cause the spread of Legionnaires’ disease. During low or no occupancy, it’s important to continue maintaining the building’s water systems to prevent bacterial growth.


Legionella can spread to humans from:

  • Water storage tanks (hot and cold)
  • Heaters and arrestors
  • Faucet flow restrictors, showerheads, and hoses
  • Fountains, ice machines, and hot tubs
  • Centrally installed humidifiers, misters, atomizers, or air washers
  • Electronic faucets, eyewash stations, and medical equipment that use water
  • Any other point where humans come in direct contact with water in the building

If the building’s water systems weren’t operating for extended periods, you’ll need a re-occupancy plan that addresses all the risks involved.

Diagram showing possible sources of Legionella contamination in buildings




What Should Your Building Re-Occupancy Plan Include?

The re-occupancy plan will need to consider all the risks involved in the building’s water system to ensure the safety of occupants. You can follow this checklist once you’ve completed your risk assessment and identified any areas of concern.

  • Develop a timeline for occupancy according to the areas of the building/buildings that will reopen.
  • Discuss treatment and equipment needs with your water treatment service provider.
  • Establish a flushing regime and maintain it until re-occupancy (remember to keep records of your flushing regimen). 
  • Inspect all mechanical equipment and effect repairs if you discover any operational issues.
  • Clean all aerators with scale buildup. 
  • Change all filters in drinking fountains, ice machines, or any other filtered outlet.  
  • Disconnect and drain any ice machines or other water sources that weren’t operating for more than seven consecutive days. 
  • Conduct supplemental disinfection, flushing, or treatment as required and according to manufacturer’s guidelines.
  • Develop a testing plan for Legionella and any other biofilms that may be present in the system.
  • Implement any corrective actions required. 


Where and When to Test for Legionella and Other Bacteria

As extended shutdowns are special circumstances, you must test for Legionella before allowing reoccupation of a building. You’ll need to develop a sampling plan to determine if you’ll need to conduct any corrective actions, which may include upgrading faucets, drains, and other outlets. 


To identify the risk level of your building water systems, you should:

  • Collect samples from different representative locations and outlet types throughout the building
  • Start sampling two to three weeks before the planned reoccupation (giving you enough time to receive results and implement any corrective actions)
  • Include hot water faucets, cooling tower basins, water features, and ice machines in your sampling plan

The results of your samples will determine whether you need remediation and to what extent your corrective actions should go to ensure safety. 

Learn more about waterborne pathogen prevention methods from the best?  Join Chicago Faucets and Dr. Janet Stout for an In-Depth Webinar about XXXXXX .

Dr. Janet Stout is Our First Healthy Building Hero and has over 30 years of experience in researching Legionella. She’s the industry expert who discovered the link between water distribution systems and the spread of Legionnaires’ disease in hospital water systems. 

In the next XXXX webinar, you’ll learn everything you need to know about how to control and prevent Legionella infections in your buildings. You can also find out more about Dr. Stout’s extensive work on preventing Legionella outbreaks from the Special Pathogens Laboratory


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Topics: Patient Care, Healthcare, Infection Prevention, Reopening Buildings Safely, Detection of Legionella, Legionnaires’ Disease, Dr. Janet E. Stout, Symptoms and Health Effects of Legionnaires’, Where and When to Test for Legionella