Evidence based review of Legionella elimination in building water systems

Abstract

Legionnaires disease can be acquired through exposure to Legionella pneumophila, a gram-negative bacteria ubiquitous in both natural and engineered water systems. Over the years, a number of disinfection techniques notably, chlorination, ozonation, thermal, UV and copper-silver ionization have been employed across different kinds of engineered water systems with diverse measures of success. Available evidence portends, most of the aforementioned techniques often have to be combined to achieve long-term efficacy. Remarkably, albeit the extensive research and reportage on Legionnaires outbreak in the developed world, very few studies have been carried out with regards to Africa. We reviewed existing literature on the application of the aforementioned techniques in buildings. Our study concurs with earlier studies; most of the disinfection techniques will have to be combined to achieve the desired efficacy. We found very scanty studies on Legionella or reportage of its outbreak within Africa. Our study also found very little in terms of any of the techniques been applied with the specific aim of reducing Legionella proliferation in engineered water systems within Africa. This is alarming, especially, on a continent where several communities have little or no access to quality water and healthcare. In light of the above, stronger measures such as sensitization, pro perly managed water distribution systems, as well as policies aimed at enforcing national and international guidelines on Legionella control is recommended.