Legionella
Author: Ryan Milne ~ Ecosafe
( Article Type: Explanation )
Legionella bacteria are found naturally in the environment (water and soil) and are responsible for causing the respiratory condition called Legionnaire’s disease. Legionnaire’s disease is considered very serious and responsible for numerous fatalities worldwide.
The name ‘Legionnaire’s disease’ originated in 1976 following an outbreak of a respiratory illness (pneumonia-like) infecting 182 people and causing 29 deaths at an American Legion members’ conference in Philadelphia, USA. Today there are an estimated 25 000 cases of Legionnaire’s disease every year in the USA alone, with underreporting still believed to be a significant problem.
Because Legionella bacteria are found naturally all over the world it can be expected that the potential exists for Legionella to enter and proliferate within the domestic and commercial water systems we come into contact with on a daily basis.
In order for the bacteria to cause ill health effects, a susceptible individual has to be exposed and inhale the contaminated aerosol (water droplet containing the Legionella bacteria) and thus become infected. Unless identified and treated immediately the disease will worsen, become more severe and potentially result in fatality.
The realisation that risks are endemic in systems previously not considered as posing high risks (e.g. domestic hot and cold systems, air-handling units, storage tanks, showers, water features, spa baths, bottle washers, sprinklers etc.) has become far more evident and therefore justifies the need for additional scrutiny and management of these systems.
The most concerning issues surrounding Legionella within South Africa are the general lack of awareness and the lack of statistics pertaining to the diagnosis of Legionnaire’s disease. These two factors result in the true scale of the problem being unquantifiable and largely unknown! In addition, a grave concern is the already high and ever-increasing number of immunocompromised individuals (typically suffering from HIV and TB) who have an increased susceptibility to respiratory diseases such as Legionnaire’s disease.
Although there have only been relatively few isolated incidents reported within South Africa, there is no doubt that the prevalence of these types of incidents is going to increase dramatically as a result of increased awareness and environmental pressure as the UK and US trends surrounding health and safety continue to emerge within South Africa.
Effective Management can be viewed as a five-tier approach, with the implementation of practical and realistic solutions:
- Legionella risk assessment
- Remedial works (site specific)
- Chemical and thermal treatment
- Cleaning/housekeeping
- Monitoring and record-keeping
