The HSE has launched a TB-screening programme for all pupils and staff at a Cork primary school.
It comes after three pupils at the school yesterday tested positive for the disease. The three are now under specialist paediatric care.
Tuberculosis or TB usually affects the lungs, but can affect any part of the body.
No source for this outbreak has been yet found, but screening is underway for all pupils and staff at the city school.
In a statement released last night, the HSE said the investigation of this cluster of cases was progressing in line with national TB contact-tracing guidelines.
A HSE outbreak control team is said to be co-ordinating the investigation and school management are liaising closely with that team.