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• Tepid water temperatures, absence of a disinfectant residual, excessive
water age and the presence of nutrients, such as phosphates, promote
proliferation of
Legionella
.
• The presence of
Legionella
bacteria in building water 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 susceptible persons by inhalation or aspiration.
• Yet, there remain significant unknowns and methodological
limitations. For example:
• An acceptable concentration of
Legionella
has not been established.
• The results of water sampling and culture have not been shown to
correlate with or predict epidemiological data.
• There is no scientific consensus on end-points for remediation.
Notwithstanding important knowledge gaps, there is general agreement
thatmitigating the intrusion, amplification and environmental transmission
of
Legionella
can prevent legionellosis associated with building water
systems. However, there are practical challenges:
• Building water systems vary substantially in their purpose, design
and propensity for transmission of
Legionella
.
• Management of other physical, chemical and microbial hazards may
conflict with best practices for preventing legionellosis.
• Water conservation and energy efficiency initiatives may be
inconsistent prevention of legionellosis.
With chapters contributed by international experts in the various
aspects and dimensions of
Legionella
and legionellosis, this book informs
