Singapore's National University Hospital (NUH) has recalled 178 paediatric patients - including 131 under the age of two years - who were cared for by a nurse now confirmed to have tuberculosis, the media reported on Friday.
It also includes 34 children who have received a transplanted organ and are on immunosuppression drugs, and therefore at higher risk than normal children, the Straits Times reported.
Associate professor Daniel Goh, head of paediatrics at NUH, said the risk of any of the children contracting TB from the nurse is "very low", especially as she had donned a mask while working.
But the hospital is not taking any chances and is recalling patients who had been in Ward 47 since July, Goh said.
The first patients were at NUH for screening on Tuesday and more will be screened over the coming weeks.
The nurse, who is on medical leave for two weeks, will resume work as being on treatment means she is not contagious. Her colleagues in the ward have all been tested and found negative.
So far this year, 1,252 new TB cases have been diagnosed in Singapore.