The Problem of Legionnaires’ Disease in Hospitals

Legionnaires' disease has been recognized as an important cause of hospital-acquired pneumonia. Inhalation of aerosols of water contaminated with Legionella from cooling towers, showers, faucets, respiratory therapy equipment, and room-air humidifiers is believed to be the primary mechanism of entry of these organisms into a patient's respiratory tract. About 30% of sporadic cases of hospital- acquired pneumonia are caused by Legionella and the mortality rate is as high as 80%, usually is immunosuppressed patients who did not receive appropriate antibiotics. A combination of culture of respiratory secretions and urinary antigen detection by immunofluorescence offer the best method for diagnosis of hospital-acquired Legionnaires' disease. Emergency measures that can be used during an outbreak include superheat and flush in combination with hyperchlorination. Continuous hyperchlorination is not favoured because of high expense, marginal efficacy, corrosion of piping, and release of carcinogenic byproducts into

Keywords: Legionnares’ disease, Risk factors, Control, Surveillance