Public Health Wales is encouraging parents to get their children screened for TB, although it says the risk of the infection spreading within the school is low.
Screening for tuberculosis will today be offered to pupils at Ysgol y Strade school in Llanelli.
The 124 pupils at the secondary school are those identified as having around eight hours of close contact with the member of staff.
Tests will also be offered to 21 members of staff identified as close contacts of the patient.
More top news
Subsidies to landowners should be conditional on them allowing mobile phone masts on their land, according to a National Assembly Committee.
Tata Steel have formally unveiled the merger of their European steel operations with German company Thyssenkrupp
Former England Under-21 Mawson swept home from a corner early in the second half before Jordan Ayew wrapped up a 2-0 third-round win.