LEGIONELLA - World Health Organization

A person involved in implementing the WSP should be responsible for risk communication.
This person should also be responsible for developing a risk management plan (to effectively
convey the WSP to all parties involved in the process, and to other entities where appropriate).
The plan should clearly identify and interpret the goals of the risk assessment and the WSP;
it should include:
• modes of communication to be used
• background information on the risk posed by Legionella, derived from the risk assessment
and system assessment
• the goals of the WSP in addressing the risk posed by Legionella
• content and target audiences for communication
• sources of further information about the water system and Legionella contamination.
Communication strategies should include procedures for promptly advising stakeholders of
any significant incident in the water system. This includes:
• notifying the public health authority
• making summary information available to the public
• establishing mechanisms for receiving and responding to community concerns.
The agencies responsible for monitoring should develop strategies for disseminating and
explaining the significance of health-related information.
3.4 Surveillance
Surveillance is the systematic collection, orderly consolidation, and analysis of data to verify
that health-based targets, system assessments and control measures are operating properly. It
might include:
• internal audit and external audit (by the health department) to confirm that operational
monitoring and corrective actions are being undertaken as stated in the WSP
• monthly heterotrophic colony counts at the tap and in the source water (to track trends
and changes, rather than as an absolute indicator, and to be undertaken by an accredited
laboratory)
• six-monthly sampling for legionellae in water at source and at the tap.
LEGIONELLA AND THE PREVENTION OF LEGIONELLOSIS