Hostname: page-component-7c8c6479df-7qhmt Total loading time: 0 Render date: 2024-03-19T07:39:08.123Z Has data issue: false hasContentIssue false

A model for autumn outbreaks of Legionnaires' disease associated with cooling towers, linked to system operation and size

Published online by Cambridge University Press:  15 May 2009

R. H. Bentham
Affiliation:
Repatriation General Hospital, Daws Road, Daw Park, South Australia 5041
C. R. Broadbent
Affiliation:
Department of Administrative Services, Canberra, Australia
Rights & Permissions [Opens in a new window]

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Cooling towers have been demonstrated to be amplifiers and disseminators of legionella, the causative organism of Legionnaires' disease. Community outbreaks associated with cooling towers have been reported with several common factors. Small towers (< 300 kW) have predominantly been implicated in outbreaks. Cooling tower-associated outbreaks are most frequent in autumn, and frequently implicated systems have been operated after a period of shutdown.

This paper reports field study data relating system operation to legionella colonization of systems. Operating systems have been shown to be more frequently colonized by legionella than shutdown systems. In some cases operation of systems after periods of shutdown raised legionella concentrations from below detection limits to between 50 and 950 c.f.u./ml within 10 min.

These data and previously reported data relating to biofilm and sediment colonization of the systems, and community outbreaks of Legionnaires' disease, have been used to develop a model explaining the seasonal nature of outbreaks associated with irregularly operated, small cooling tower systems.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1993

References

REFERENCES

1.Christopher, PJ, Noonan, LM, Chiew, R. Epidemic of Legionnaires' disease in Wollongong. Med J Aust 1987; 147: 127–8.Google Scholar
2.Christley, S, Rubin, G, Christopher, P. Legionnaires' disease Sydney. NSW. Department of Health, New South Wales Epidemiology and Health Services Evaluation Branch Report. April 1989.Google Scholar
3.Bhopal, RS, Fallon, RJ. Seasonal variation of Legionnaires' disease in Scotland. J Infect 1991; 22: 153–60.Google Scholar
4.Fliermans, CB. State of the art lecture. Philosophical ecology: Legionella in historical perspective. In: Thornsberry, C, Balows, A, Feeley, JC, Jakubowski, W, eds. Legionella: proceedings of the second international Legionella symposium.Washington:American Society for Microbiology1984:285–9.Google Scholar
5.Dondero, TJ jnr, Rendtorff, RC, Mallison, GF et al. An outbreak of Legionnaires' disease associated with a contaminated air-conditioning cooling tower. New Eng J Med 1990: 302: 7: 365–70.Google Scholar
6.Timbury, MC, Donaldson, JR, McCartney, AC, Winter, JH, Fallon, RJ. How to deal with a hospital outbreak of Legionnaires' disease. J Hosp Infect 1988; 11: 189–95.Google Scholar
7.Addis, DG, Davis, JP, Wand, PJ, McKinney, RM, Gradus, MS, Martins, RR. Two cases of community acquired Legionnaires' disease: Evidence for association with a cooling tower. J Infect Dis 1989; 159: 572–5.Google Scholar
8.Glick, TH, Gregg, MB, Berman, B, Mallison, G, Rhodes, W, Kassanoff, I. Pontiac fever: an epidemic of unknown etiology in a health department: I. Clinical and epidemiological aspects. Am J Epidemiol 1978; 107: 149–60.Google Scholar
9.Bartlett, CLR, Macrae, AD, Macfarlane, JT. Legionella Infections. London: Edward Arnold, 1986.Google Scholar
10.Breiman, RF, Cozen, W, Fields, BS et al. Role of air sampling in investigation of an outbreak of Legionnaires' disease associated with exposure to aerosols from an evaporative condenser. J Infect Dis 1990; 161: 1257–61.Google Scholar
11.Garbe, PL, Davis, BJ, Weisfeld, JS et al. Nosocomial Legionnaires' disease. Epidemiologic demonstration of cooling towers as a source. JAMA 1985; 254: 521–4.Google Scholar
12.Johnson, AG. Report on disinfecting and cleaning of cooling towers at Repatriation General Hospital – Daw Park. Australian Department of Housing and Construction 1986.Google Scholar
13.Levy, M, Westley-Wise, V, Frommer, M, et al. Report on Legionnaires' disease in South Western Sydney, April 1992. South Western Sydney Area Health Service Public Health Unit. New South Wales Health Department 1992.Google Scholar
14.Mitchell, E, O'Mahony, M, Watson, JM, et al. Two outbreaks of Legionnaires' disease in Bolton Health District. Epidemiol Infect 1990; 104: 158–70.Google Scholar
15.Morton, S, Bartlett, CLR, Bibby, LF, et al. Outbreak of Legionnaires' disease from a cooling water system in a power station. Br J Indust Med 1986; 43: 630–5.Google Scholar
16.Nordstrom, K, Kallings, I, Dahnsjo, H, Clemens, F. An outbreak of Legionnaires' disease in Sweden: Report of sixty-eight cases. Scand J Infect Dis 1983; 15: 4355.Google Scholar
17.O'Mahony, M, Lakhani, A, Stephens, A, Wallace, JG, Youngs, ER, Harper, D. Legionnaires' disease and the sick-building syndrome. Epidemiol Infect 1989; 103: 285–92.Google Scholar
18.O'Mahony, M, Stanwell-Smith, RE, Tillett, HE et al. The Stafford outbreak of Legionnaires' disease. Epidemiol Infect 1990; 104: 361–80.Google Scholar
19.Brundrett, GW. Legionella and building services. Oxford: Butterworth-Heinemann. 1992.Google Scholar
20.Broadbent, CR, Marwood, LN, Bentham, RH. Legionella ecology in cooling towers. Australian Institute of Refrigeration. Air Conditioning and Heating Journal 1992: 10: 2034.Google Scholar
21.Bentham, RH, Broadbent, CR, Marwood, LN. The influence of the sessile population in the Legionella colonization of cooling towers. In: Barbaree, JM, Breiman, RF, Dufour, AP. eds. Legionella: current status and emerging perspectives. Washington DC: American Society for Microbiology. 1993: 267–9.Google Scholar
22.Dennis, PJL. Isolation of legionellae from environmental specimens. In: Harrison, TG, Taylor, AG. eds. A laboratory manual for Legionella. New York: John Wiley. 1988: 3143.Google Scholar
23.Costerton, JW, Cheng, K-J, Geesey, GG, et al. Bacterial biofilms in nature and disease. Ann Rev Microbiol 1987: 41: 435–64.Google Scholar
24.Herwaldt, LA, Gorman, GW, McGrath, T et al. A new Legionella species, Legionella feeleii species nova, causes Pontiae fever in an automobile plant. Ann Intern Med 1984; 100: 333–8.Google Scholar
25.Broadbent, CR. Practical measures to control Legionnaires' disease hazards. Australian Institute of Refrigeration. Air Conditioning and Heating Journal 1987; July: 2230.Google Scholar
26. Technical Information 178 ME, Measures to control Legionnaires' disease hazards in buildings. Australian Department of Administrative Services. 1987.Google Scholar
27.Smith, MH, Stewart, CJ. Air conditioning condenser cooling systems: Cost considerations. Building Services Research Information Association (UK). Technical Memorandum 1/90. 1990.Google Scholar