LEGIONELLA - World Health Organization

Chapter 6 Health-care facilities
Martin Exner, Philippe Hartemann, Louise Lajoie
This chapter describes how a water safety plan (WSP) can be applied to assessing and managing
the risks associated with Legionella in health-care facilities. Infections acquired in a healthcare
setting are referred to as “nosocomial”.
This chapter looks at different infection reservoirs in hospitals, such as cold and hot-water
systems or plumbing systems, cooling towers, bathing pools and dental units. For information
on infection control measures in cooling towers and bathing pools, the reader should consult
Chapters 5 and 8, respectively.
This chapter should also be read in conjunction with Chapter 3, which discusses the different
elements that make up a WSP, and shows how a WSP fits within the framework for safe water
quality developed by the World Health Organization (WHO). As explained in Chapter 3, a
WSP has 10 steps that fit within the three main areas of system assessment, monitoring and
management and communications (see Figure 3.2). A WSP must be comprehensive, and all
10 steps should be implemented in assessing and managing the risks associated with Legionella.
However, this chapter focuses on parts of the WSP where information specific to health-care
facilities is needed.
6.1 Background
In this chapter there is a risk assessment concerning different infection reservoirs in hospitals,
such as cold and hot-water systems or plumbing systems, cooling towers, bathing pools and
dental units. For infection control measures focusing on cooling towers and bathing pools,
refer to the relevant chapter of this guideline.
A WSP needs to be comprehensive; however, an overview of such a plan is shown in Table 6.1,
as an example of the type of information a plan might contain. As explained in Chapter 3, a
WSP is part of a framework for safe water quality that also includes health-based targets and
surveillance.
Nosocomial cases usually make up a small proportion of reported cases of legionellosis.
However, the proportion of cases that are fatal tends to be much higher with nosocomial
infections than with community-acquired infections. Therefore, health-care facilities have a
special responsibility for preventing Legionnaires’ disease.
Health-care facilities include hospitals, health centres, hospices, residential care facilities and
dialysis units. These institutions are settings in which people with predisposing risk factors
for Legionella infections are more likely to be present, and in which medical devices that can
LEGIONELLA AND THE PREVENTION OF LEGIONELLOSIS