Request for info on LEGIONELLA

Brian Shelton bshelton at
Tue Mar 21 13:38:35 EST 1995

In article <3k9e4n$cd6 at> ee_f635 at (Anthony Waghorn) writes:
>From: ee_f635 at (Anthony Waghorn)
>Subject: Request for info on LEGIONELLA
>Date: 16 Mar 1995 13:23:35 GMT

>Does anyone have information on Legionella ( papers written etc)

>  especially problems in the control of Legionella in air conditioning systems

>    O                    ""~""                     O
>    o                   ( o o )                    o
>| Tony Waghorn                 167a Hook Rd,Surbiton  |
>| Phone 0181-397-7934 oooO       SURREY   KT9 5AR     |
>| ee_f635 at (   )   Oooo.                    |
>+---------------------\ (----(   )--------------------+
>                       \_)    ) /
>                             (_/

It depends on what you mean by air-conditioning systems.  Cooling towers are 
notoriously contaminated with Legionella and have been well documented 
in disease transmission.  Most cooling towers test negative for the presence 
of the organism.  It is rare to find cooling towers with high counts 
(>1000CFU's occurs less than 3% of all towers).  It is the towers with 
elevated counts that represent the greatest risk.  In fact , this was the 
subject of my MPH thesis.

Air-conditioning condensate trays on the other hand are different.  They 
usually have cold water, temperatures not likely to grow the organism to high 
concentrations, and the condensate is not aerosolized as it is in cooling 
towers -- a necessary event to allow for inhalation exposure.

If you have any further questions, or wish reprints, you can email me at 
bshelton at

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