Campus Updates
Information on Legionella Bacteria
17 Aug 2012 - 31 Aug 2012
Dear colleagues and students,
I would like to report to you on the occurrence of traces of Legionella bacteria found in a recent water quality test in the buildings of the Centennial Campus.
The University Estates Office has conducted regular water quality tests within the new buildings and a preliminary result on July 24 suggested possible traces of Legionella bacteria. A full test was subsequently conducted on samples collected on Aug 1 and the results obtained today for some of those samples show that they do contain certain species of Legionella bacteria. (It takes about two weeks to obtain the results due to time taken in the incubation of samples)
Legionnella bacteria are often found in environments like water tanks and hot and cold water systems and their presence is not uncommon in new buildings. The occurrence is exacerbated by the climate of tropical regions. The Estates Office has taken follow up actions in accordance with the Code of Practice of Prevention of Legionnaires’ Disease, issued by Prevention of Legionnaires’ Disease Committee including flushing and draining off of the water tanks and taps of all buildings.
We have consulted the University Health Service, the Safety Office and medical experts on the risks to which users of the new buildings may be exposed. The UHS advised that for normal healthy persons the risks of contracting Legionnaires' Disease in the new buildings are insignificant. It must be emphasized that no confirmed cases of Legionnaires' Disease have been reported.
The UHS has uploaded information about Legionnaires' Disease on the following website, http://www.uhs.hku.hk/legion.htm Your attention is drawn to the following key points:
l The disease is transmitted by inhalation of contaminated water vapour. It is NOT transmitted by person to person contact, eating or drinking, i.e. the bacteria enter the body through inhalation of water mist.
l Most people exposed to the bacteria do not become ill and continue normally without any treatment.
l People at higher risk include persons of advancing age, smokers or heavy drinkers and those with weakened immunity.
We will monitor the situation by conducting more tests for Legionella (and other water quality measures), as we remedy the situation by continued flushing of water tanks and taps, and other appropriate methods. We have also consulted Professor KY Yuen, Chair of Infectious Diseases of the Department of Microbiology on the matter and the manner in which we should deal with the situation. He has confirmed that there is no need for alarm and that the occurrence is not unusual. However, since some samples contain bacterial counts above acceptable levels, we are advised to follow standard procedures to cleanse the water system.
Please rest assured that the University is taking proactive measures in addressing the issue in accordance with established guidelines. However, should you wish to drink tap water in the new buildings it is advisable that it first be boiled. Legionnella bacteria cannot survive at temperatures above 75 degrees Celsius. Nevertheless, if you are concerned about the possibility of contracting the disease, please consult one of the UHS doctors.
Thank you for your attention.
Professor John Malpas
PVC (Infrastructure)