13 July 2015
In view of the latest findings, the Centre for Health Protection (CHP) of the Department of Health today (July 13) provided further information on the epidemiological investigation into a case of Legionnaires' disease (LD) reported on May 28 affecting a man aged 72 who lives in Mun Ching House, Kai Ching Estate.
As part of the epidemiological investigation, water samples and environmental swabs have been taken from Mun Ching House for testing. Upon testing by the CHP's Public Health Laboratory Services Branch, all eight pairs of water samples taken from water outlets of the patient's residence on June 18 had been tested positive for Legionella pneumophila at a level of 1.3 to 330 colony-forming units per millilitre (cfu/ml) while one out of the four environmental swabs taken from the patient's residence had been tested positive for Legionella pneumophila. Besides, water sample taken from the roof water tank of Mun Ching House was negative.
In addition, preliminary test results today revealed that the two pairs of water samples taken from water pipes supplying the patient's flat as well as the same floor on July 6 had been tested positive for Legionella pneumophila at a level of 0.7 to 1.7 cfu/ml. One pair of water samples taken from the water pipe on the first floor of the building on the same day had also been preliminarily tested positive for Legionella pneumophila at a level of 0.3 cfu/ml.
"No other Legionnaires' disease cases have been identified in Kai Ching Estate since 2013," a spokesman for the CHP added.
Legionella are found in various environment settings and grow well in warm water (20 to 45 degrees Celsius). They can be found in aquatic environments such as water tanks, cooling towers, whirlpools and spas, water fountains and apparatus that support breathing. Use of proper design, operation and maintenance of water systems can prevent LD.
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