Tuberculosis testing will begin for South Grand Prairie High School students after a classmate showed signs of infectious disease.
Preliminary test results reveal the student had been exposed to the illness, but tests results to confirm a diagnosis will not be available for several weeks.
In the meantime, the district identified other students who may have been in close contact with the affected student and sent out letters to their parents notifying them their child will be tested.
Dallas County Health and Human Services will give skin tests to approximately 150 of the student's classmates. Results of those tests will be available two days afterward.
Children who test positive on preliminary tests will need further testing done by the Dallas County Health and Human Services.
NBC 5's Bianca Castro contributed to this report.