Only people who have been in prolonged close contact with TB sufferers are likely to catch the infection, a public health specialist said yesterday.
Dr Declan McKeown, a specialist in public health medicine with the Western Health Board, said that the likelihood of picking up tuberculosis through social or occupational contact was very low indeed.
"Usually the cases we see here are household contacts - people sleeping under the same roof as an infected person. It is actually quite a hard disease to get in this part of the world. It involves quite prolonged close contact with somebody who has sputum positive TB," he said.
The specialist's comments will help to allay fears among staff at the State's refugee applications centre in Dublin, a number of whom tested positive in an initial screening programme for TB.
Initial screening involves a skin test. If the person tested develops a reaction, further tests, including chest X-rays, are necessary to confirm a diagnosis.
The Eastern Health Board confirmed yesterday that three of the nine workers at the refugee applications centre who had tested positive in the initial screening programme had now been given the all-clear.
A statement issued by the board pointed out that no case of TB had been identified among staff at the centre so far. However, it confirmed that further tests were being carried out on six staff at present to see if they had tuberculosis.
The board said the fact that some workers had shown a positive reaction in the initial screening programme was not unexpected as it indicated only that they have been exposed to TB at some stage in the past.
Dr McKeown said it would be impossible to say when people who reacted to the skin test had been exposed to TB.