In reality Legionnaires’ disease is difficult to catch, this is borne out by fact that the UK has one of the lowest rates of Legionnaires’ disease with 4 cases per million population on average each year.
Part of the reason for this is the quality of the UK guidance on controlling Legionella in the workplace and also due to the diligence of sites managing this guidance.
Never forget that Legionella bacteria are associated with biofilms and protozoa both of which are not necessarily removed using biocides and temperature which are the primary methods outlined in guidance. Consequently there needs to be a coordinated, holistic approach to managing Legionella bacteria on site.
This is where an understanding of the Causal Chain comes in. As can be seen from the graphic above there are several components involved before somebody catches Legionnaires’ disease, not least the fact that only about 1/3rd of Legionella species and serogroups are virulent i.e. they cause illness in humans.
An understanding of this Causal Chain can help you control Legionella on site. If you need help understanding the causal chain and how to manage it and so control Legionella on your site then contact Collaton Consultancy on firstname.lastname@example.org