LEGIONELLA - World Health Organization

Chapter 9 Disease surveillance
and public health management
of outbreaks
Carol Joseph, John V Lee
This chapter describes:
• the requirements of a surveillance system for legionellosis (Section 9.1)
• results of an international scheme for surveillance for legionellosis (Section 9.2)
• methods for managing an outbreak of legionellosis (Section 9.3)
• case studies of disease outbreaks (Section 9.4).
9.1 Surveillance systems
Legionellosis is now a statutory notifiable disease in most industrialized countries. Differences
in public health surveillance systems mean that provision of Legionella data is determined by
each country’s technical ability to identify cases, produce data and allocate resources to this particular
infection. These factors are influenced by the historical, social and cultural value systems that
pertain to each country’s public health system (Anon, 1998b; WHO, 1999). Thus, a country’s
national surveillance of Legionnaires’ disease will depend on factors such as:
• infrastructure and public health laws
• adopted surveillance principles and standard operating procedures
• notification law
• data protection
• patient confidentiality
• freedom of information legislation.
The priority given to legionellosis surveillance may need to be greater than suggested by local
morbidity and mortality, because of its impact on the tourist industry.
Box 9.1 defines disease surveillance.
LEGIONELLA AND THE PREVENTION OF LEGIONELLOSIS