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.
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.
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:
If not treated early, Legionnaires’ disease can lead to:
The diagram below shows the typical lifecycle of a Legionella infection.
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.
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.
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.
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.
Source: https://www.cdc.gov/legionella/wmp/overview/growth-and-spread.html
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.
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.
The results of your samples will determine whether you need remediation and to what extent your corrective actions should go to ensure safety.
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.