Microbiological Findings of Legionellae in the Manufacture of Flat Glass: Health Risk Assessment

Legionellosis is an acute respiratory and lung disease caused by bacteria of the genus Legionella. Natural and manmade aquatic environments are the major reservoirs of Legionellae. Transmission to humans occurs through inhalation of infectious aerosols. 104 samples of water intended primarily for the cooling process in flat glass factories were examined. All samples contained varying amounts of the legionellae bacteria which are pathogenic for humans. The most serious finding was Legionella pneumophila sg.1, sbg. Pontiac. Saprophytic strains (L. rubrilucens, L. nautarum, L. worsleiensis) were also found. An increased risk of the disease is associated mainly with the operation, maintenance and cleaning of machines (grinders, washers) and cooling systems. Preventive methods include regular maintenance, the disinfection of cooling water with biocides and the implementation of risk assessment. Medical diagnosis is based on medical examinations of workers supported by specific tests used above all in cases of professionally acquired pneumonia. This will also lead to improvement of the legionellosis surveillance.