About 300 babies in Australia have been exposed to tuberculosis from an infected doctor.
Health officials said the children in the neo-natal intensive care unit and the special care baby unit of Adelaide's Women's and Children's Hospital may have come into "close and prolonged contact" with an infected doctor.
About 75 of these children are too young to diagnose, and will be treated with antibiotics to minimize the chances of infection.
The doctor was screened for TB by immigration authorities when he arrived in Australia in March this year. His chest X-ray found no trace of TB — but a routine follow-up test by health workers last week returned a positive result.
Tests for TB are ineffective in babies under three months of age.
The overseas-born doctor is on sick leave, but hospital authorities expect him to return to work after he is cured.