10
•Tepidwater temperatures, absenceofadisinfectant residual, excessive
water age and the presence of nutrients, such as phosphates, promote
proliferationof
Legionella
.
•The presence of
Legionella
bacteria in buildingwater systems is not
in itself sufficient to cause legionellosis. Other necessary factors include
transmission of
Legionella
bacteria in sufficient numbers (dose) to expose
and infect susceptiblepersons by inhalationor aspiration.
• Yet, there remain significant unknowns and methodological
limitations. For example:
•An acceptable concentrationof
Legionella
hasnot been established.
•The results of water sampling and culture have not been shown to
correlatewithor predict epidemiological data.
•There isno scientific consensus on end-points for remediation.
Notwithstanding importantknowledgegaps, there isgeneralagreement
thatmitigatingtheintrusion,amplificationandenvironmentaltransmission
of
Legionella
can prevent legionellosis associated with building water
systems.However, there arepractical challenges:
• Building water systems vary substantially in their purpose, design
andpropensity for transmissionof
Legionella
.
•Management of other physical, chemical andmicrobial hazardsmay
conflictwithbest practices for preventing legionellosis.
• Water conservation and energy efficiency initiatives may be
inconsistent preventionof legionellosis.
With chapters contributed by international experts in the various
aspects and dimensions of
Legionella
and legionellosis, this book informs
