Fumes blamed for shipyard infection
Metal fumes caused a bacterial infection at Harland and Wolff shipyard in Belfast, the health minister said.
The Public Health Agency said the potentially deadly pneumococcal disease had been detected in a number of employees.
The bacteria can cause a variety of infections including pneumonia, meningitis and blood-poisoning.
It is understood four staff were initially struck down, with tests carried out on others.
Minister Simon Hamilton said: "There is an accepted and acknowledged heightened risk for those who are welding of getting this disease from metal fumes. That is the believed source of this outbreak.
"We have been taking this matter incredibly seriously. Having identified those at risk they have been ensuring workers are provided with antibiotics for their use.
"The Public Health Agency (PHA) has shown that in this unfortunate outbreak that they have the capacity and capabilities to respond to problems such as this."
Throughout Northern Ireland, there are around 50 to 60 cases a year of invasive pneumococcal disease each year.
The bacteria which cause the infections can be spread by close contact with someone who is carrying them when that person coughs or sneezes.
They can also be spread by direct contact with respiratory secretions from an infected person, such as used paper tissues.
The PHA said people can carry the bacteria in the backs of their noses and throats without ever becoming ill, while others can go on to develop an infection.
Apart from welders, other groups of people more at risk of developing it include the very young or the very old; those with a chronic illness, such as diseases of heart, lung, kidneys, liver or diabetes; those without a spleen or with a damaged spleen; and those whose immune system is not working properly.