“Know the extent of the disease;  The identified incidence of Legionnaires’ disease varies widely according to the level of surveillance and reporting. Since many countries lack appropriate methods of diagnosing the infection or sufficient surveillance systems, the rate of occurrence is unknown. In Europe, Australia and the USA there are about 10–15 cases detected per million population per year.

Of the reported cases 75–80% are over 50 years and 60–70% are male. Other risk factors for community-acquired and travel-associated legionellosis include: smoking, a history of heavy drinking, pulmonary-related illness, immuno-suppression, and chronic respiratory or renal illnesses.”

World Health Organization – WHO