LEGIONELLA - World Health Organization

• Regulations include HSC (2000), IEE (2001) and Victorian Department of Human Services
(2001). Table 10.1 summarizes European regulations.
WHO publications relevant to the control of Legionella are listed in Box 10.1.
Current guidelines and regulations vary in scope and design, but usually include certain common
features, such as general support of a risk management approach. Some guidelines are very
broad (e.g. ASHRAE, 2000; HSC, 2000), whereas others deal with specific circumstances,
such as control of infection within health-care facilities (Allegheny County Health Department,
1997; Ehrlich, Steele & Sabatini, 2000; CDC, 2003) or travel-related disease (CDC, 1996,
1997a; CDC, 2003; EWGLINET, 2003).
Box 0. WHO publ cat ons relevant to the control of Legionella
• Guidelines for Drinking-water Quality, third edition (WHO, 2004)
• Guidelines for Safe Recreational Water Environments, Volume 1 —
Coastal and Fresh Waters (WHO, 2003)
• Guidelines for Safe Recreational Water Environments, Volume 2 —
Swimming Pools, Spas and Similar Recreational Water Environments (WHO, 2006)
• Health Aspects of Plumbing (WHO, 2006)
• Legionella and the Prevention of Legionellosis (WHO, 2007)
• Guide to Ship Sanitation (WHO, 2007)
10.2 Legionella testing
An issue that has been the subject of some debate is the role of testing programmes for the
presence or absence of Legionella, and whether such testing should be included in regulations.
Chapter 11 discusses some of the issues involved in such testing programmes, which include
lack of correlation between test results and human health risk (Kool et al., 1999; Bentham, 2002),
and uncertainties about whether or not detected legionellae are infectious (Bentham, 2000).
Much of the debate about routine testing for Legionella has focused on the potential for
over-reliance on results at the expense of risk management strategies. Legionella testing is not
suitable for operational monitoring, in the same way that enteric pathogens and indicator
bacteria are not suitable for operational monitoring of drinking-water supplies (WHO, 2004).
However, Legionella testing can be a useful component of monitoring to verify the performance
of water safety plans (WSPs), and it is recommended for cooling towers, hot tubs and water
distribution systems where people at high risk might be exposed (e.g. in health-care facilities).
Legionella testing can also be undertaken as part of:
• investigation of an outbreak
LEGIONELLA AND THE PREVENTION OF LEGIONELLOSIS