Legionnaires' disease bacterium: Further tests at Newtownabbey school 4 February 2013 Last updated at 08:06 Further samples are due to be taken from a County Antrim school where bacterium which can cause Legionnaires' disease has been discovered. Hill Croft Special School in Newtownabbey closed on Friday and will remain closed for at least a week while further tests are carried out. The bacterium was found in a disused shower block at the school. Ray Gilbert of the North Eastern Education and Library Board said the system was flushed out at the weekend. He said that work had been done to descale and disinfect the water system, and further tests would be carried out on Monday. "The analysis of the samples takes up to 10 days but after five or six days you get an indication as to whether or not there is significant bacteria present," he said. Legionnaires' disease The bacterial disease causes a lung infection or pneumonia It is caused by a bacteria known as Legionella pneumophila, which is found in natural and man-made water systems Symptoms first appear between two and 10 days after exposure to the bacteria and if identified quickly can be treated with antibiotics The disease and bacterium were discovered after an outbreak at an American Legion convention in Philadelphia in 1976, which led to the name Source: BBC Health If there is a significant growth at that point in time, obviously, for safety reasons it has to be treated as potential Legionella. He said the school was hopeful of getting results of the samples by next Monday. Meanwhile, steps are being taken to keep in contact with parents and decide if the children can be taught elsewhere or work sent home. In a statement at the weekend, the board said: "We would like to reassure anyone who may be concerned that the area where the bacterium was found has not been in use by the pupils or staff at the school."