LEGIONELLA - World Health Organization

Birthing pool water — control measures
Birthing pools should be designed for the purpose, and should be physically cleaned and
disinfected both before and after birth (noting that the high amount of organic material will
inactivate residual biocides). Where hoses are used for filling, they and any connectors should
be disinfected before use. A risk assessment and pool management plan should be designed
that takes into account the intermittent use and storage conditions of the pool. Disposable
liners are available for pools.
Disinfection — control measures
Monochloramine is likely to be more effective for disinfection than free chlorine, because it
is more resistant and a residual is more likely to persist to the point of delivery; also, it is more
likely to penetrate biofilms. Hospitals supplied with drinking-water treated with monochloramine
as the residual disinfectant have been shown to be less likely to have a reported outbreak of
Legionnaires’ disease than those using water treated with free chlorine. In contaminated hospitals,
the proportion of sites testing positive was inversely related to the free residual chlorine
concentration (P = 0.01) (Kool, Carpenter & Fields, 1999; Kool et al., 1999).
6.4.2 Monitor control measures
This step involves defining the limits of acceptable performance and how these are monitored
(i.e. what will be monitored, and how, when and by whom). Again, this section should be
read in conjunction with Chapters 4 and 5.
To protect the most vulnerable patients in hospitals, there are distinct requirements, which
depend on the risk estimation. For example, one requirement might be to maintain legionellaefree
water in systems that produce aerosols in showers, in wards or in hospital rooms where
there are immunocompromised patients.
The results of monitoring allow corrective actions (discussed in Section 6.5.1, below) to protect
public health to be taken.
6.5 Management and communication
This section should be read in conjunction with Section 3.3.3 of Chapter 3. The steps involved
in management and communication are to:
• develop supporting programs
• prepare management procedures (Section 6.5.1)
• establish documentation and communication procedures (Section 6.5.2).
LEGIONELLA AND THE PREVENTION OF LEGIONELLOSIS