American Legionnaires Discover an Evil Pathogen

If you are operating a commercial or industrial facility that is water-cooled, operates heat transfer systems – such as cooling towers or fluid coolers, or runs warm water sources such as domestic hot-water systems, you need to have a Legionella risk assessment.

The Bellevue-Stratford hotel was the mecca of Philadelphia, Pennsylvania for local and international powerful, wealthy, famous, and politically prestigious. The doors of the Bellevue swung open and closed for thousands of charity balls, weddings, meetings, dining of the famous, club gatherings, and was a symbol of notoriety and fame.

Little did anyone know that the Bellevue would end up a Petri dish for a deadly undiscovered bacterium- would have been the perfect candidate for Legionella risk assessments.

In 1976, the Bellevue-Stratford hotel was host to a meeting of the Pennsylvania American legion that resulted in 200 participants becoming ill and 34 of those participants ending up dead. It was July 21, 1976 when over 4000 people gathering with their family and friends visited the Bellevue hotel for the 58th American Legion’s convention-a definite time when a Legionella risk assessment could have saved lives. Of the 4000 attending the meeting, 600 of them were guests staying in the hotel.

It wasn’t until July 27, 1976 that anyone noticed the seriousness of the situation. The first sign of trouble was a death in Sayre of an Air Force veteran that had attended the convention at the Bellevue. As the American Legionnaires sequentially died, scientists were scratching their heads on identifying the bacteria.

The discovery was made by a Dr Joseph McDade, who was a Rickettsiologist working for the CDC. The bacteria were identified as waterborne pathogens that can be deadly and is what we know today as Legionella.

The need for Legionella risk assessments is pertinant and for certain structures it is mandatory. Some of the systems that should have Legioinella risk assessments are as follows:

  • Cooling towers
  • Evaporative condensers
  • Fluid coolers
  • Humidifiers
  • Misters
  • Domestic water systems
  • HVAC systems
  • Hot Tubs
  • Hotels
  • Hostels
  • Offices
  • Hospitals
  • Gyms / Health Clubs

Some of the things that should be completed during a Legionella risk assessment are as follows:

  • Evaluation of the building’s design.
  • Review of the building’s operation, maintenance and treatment programs in an attempt to decrease the risk of problems related to waterborne pathogens.Ensure compliance with applicable guidelines and regulations.
  • Provide appropriate guidelines to Legionella control.
  • Identification and evaluation of potential sources of risk.
  • The particular means by which exposure to Legionella bacteria is to be prevented.
  • If prevention is not availably possible, changes need to be implemented to decrease risk from exposure to Legionella bacteria.

If the Legionella risk assessment demonstrates no potential risk- no further assessment or procedures are needed. If scenarios change, than the Legionella risk assessment needs to be reviewed and considered for any implementation of changes to the engineering that would be warranted.

Legionella risk assessments need to be conducted regularly and/or whenever there is question of the original Legionella risk assessments validity.