STOP THAT PIGEON 

THIS AIRCONDITIONING SYSTEM
SERVES A MAJOR BANK IN PERTH 
WESTERN AUSTRALIA

THE BACTERIA COUNT IN THIS UNIT WAS 225,000 Cfu`s/ml
THE HIGHEST LEVEL THAT WE HAVE FOUND IS 416000 Cfu`s/ml

In recent years, the existence of many previously unrecognized bacteria and viruses in recirculated liquids have come to the public’s attention. The 1976 outbreak of Legionnaires’ disease led to the recognition that Legionella exists in most water supplies. Today, over 40 different strains of Legionella have been identified and increasing numbers of buildings test their water specifically for this bacteria. There are now more than nine major studies in which Legionella ranks among the three microbial agents of sporadic community-acquired pneumonia.
The threat of hospital-acquired infection is intensified due to the high percentage of immuno-suppressed patients receiving medical treatment.
It is estimated that 20,000 to 100,000 cases of sporadic cases occur every year.

Hospital-acquired Legionnaires’ disease is a major problem. Studies indicate hot water distribution systems to be the main source of patient exposure to the Disease

Legionella is found in virtually all natural aquatic environments, such as lakes, rivers and streams, and man-made habitats including cooling towers, evaporative condensers, therapy pools, and domestic water distribution systems. The colonization of water systems by Legionella depends on a combination of several factors: sediment and scale accumulation, commensal water bacteria, and temperature. In the past, hospital engineering and infection control personnel were usually concerned about acquiring Legionella from cooling towers
Although these are a potential threat, current research indicates potable water distribution systems are the most likely to contain Legionella and pose the greatest threat. Virtually all hospital outbreaks of Legionnaires disease occurring since 1982 have implicated water distribution systems rather than cooling towers. The most current research indicates Legionella is transmitted through aspiration, aerosolization , through showers or faucets), or direct exposure to Legionella during respiratory tract manipulation.Organ transplant patients, elderly, smokers, lung disease patients appear to be at greater risk.