Cooling towers are associated with transmission of the bacterium
Legionella, the agent of Legionnaires' Disease and Pontiac Fever. This
study analyzed the numbers of Legionella pneumophila collected from 1,336
commercial and industrial cooling towers over a 4-year period. These cooling towers were
routinely treated with biocides to reduce the growth of Legionella.
Comparisons of Legionella numbers showed that 46% of the cooling towers
contained no detectable L. pneumophila, 59% had counts of 10/ml or less,
90% had counts at or below 200/ml, and only 3% contained over 1,000/ml. Cooling tower
samples containing Legionella occurred every month of the year with
higher numbers during the summer months when more cooling towers were operating.
BrownJ, HortK, BouwmanR, CaponA, BansalN, GoldthorpeI. Investigation and control of a cluster of cases of Legionnaires' Disease
in western Sydney. Commun Dis Intell. 2001 Apr;25(2):63–6.
2.
CherryWB, PittmanB, HarrisPP, HebertGA, ThomasonBM, ThackerL. Detection of Legionnaires' Disease bacteria by direct immunofluorescent
staining. J Clin Microbiol. 1978; 8:329–38.
3.
FieldsBS, BensonRF, BesserRE. Legionella and Legionnaires' Disease: 25 years of
investigation. Clin Microbiol Rev. 2002; 15:506–26.
4.
FliermansCB, CherryWB, OrrisonLH, SmithSJ, TisonDL, PopeDH. Ecological distribution of Legionella
pneumophila. Appl Environ Microbiol. 1981; 41:9–16.
5.
FriedmanS, SpitalnyK, BarbareeJ, FaurY, McKinneyR. Pontiac Fever outbreak associated with a cooling tower. Amer J Publ Hlth. 1987; 77:568–72.
6.
GilpinRW, DillonSB, KeyserP, AndrokitesA, BerubeM, CarpendaleN. Disinfection of circulating water systems by ultraviolet light and
halogenation. Water Res. 1985; 19:839–48.
7.
HorneiB, EwigS, ExnerM, TartakovskyI, LajoieL, Surman-LeeS. Laboratory aspects of Legionella. In: BartramJ, ChartierY, LeeJV, PondK, Surman-LeeS, editors. Legionella and the prevention of legionellosis. Geneva: World Health
Organization; 2007. p. 175–93.
8.
HussongD, ColwellRR, O'BrienM, WeissE, PearsonAD, WeinerRM. Viable L. pneumophila not detectable by culture on agar
media. BioTechnol. 1987; 5:947–50.
9.
KimaBR, AndersonaJE, MuelleraSA, GainesWA, KendallAM. Literature review—efficacy of various disinfectants against
Legionella in water systems. Water
Res. 2002; 36:4433–44.
10.
KusnetsovJM, OttoilaE, MartikainenPJ. Growth, respiration and survival of Legionella
pneumophila at high temperatures. J Appl
Bacteriol. 1996; 4:341–7.
11.
LaneJ, FieldsB, MillerR. Cooling towers, drift, and legionellosis. CTI
J. 2010; 31:30–47.
Negron-AlviraA, Perez-SuarezI, HazenTC. L. pneumophila spp. in Puerto Rico cooling
towers. Appl Environ Microbiol. 1988; 54:2331–4.
14.
Occupational Safety and Health
Administration. OSHA technical manual, section II—chapter 7,
Legionnaires' Disease. Washington, DC: OSHA. 40 pages.
15.
ParthuisotN, BinetM, Touron-BodilisA, PougnardC, LebaronP, BaudartJ. Total and viable Legionella pneumophila cells in hot and
natural waters as measured by immunofluorescence-based assays and solid phase
cytometry. Appl Environ Microbiol. 2011; 77:6225–32.
16.
RangelKA. Systematic review of biocides used in cooling towers for the prevention
and control of Legionella spp. contamination. CTI J. 2010; 31:72–9.
17.
SteinertM, EmodyL, AmannR, HackerJ. Resuscitation of viable but nonculturable L. pneumophila
Philadelphia JR32 by Acanthamoeba castellanii. Appl Environ Microbiol. 1997; 63:2047–53.
18.
Surman-LeeS, FieldsB, HorneiB, EwigS, ExnerM, TartakovskyI. Ecology and environmental sources of
Legionella. In: BartramJ, ChartierY, LeeJV, PondK, Surman-LeeS, editors. Legionella and the prevention of legionellosis. Geneva: World Health
Organization; 2007. p. 29–38.
19.
Wisconsin Section of Acute and Communicable
Disease Epidemiology, Bureau of Community Health and Prevention, Division of Health,
Wisconsin Department of Health and Social Services. Control of
Legionella in cooling towers: Summary guidelines. (POH 4242 rev. 8/87). Madison, WI, 1987.
