Diagnosis of Perinatal TB Culture of tracheal aspirate, gastric washings, urine, and cerebrospinal fluid (CSF) Chest x-ray Sometimes skin testing All neonates with suspected congenital tuberculosis and infants born to mothers who have active TB should have a chest x-ray and culture of tracheal aspirates, gastric washings, and urine for acid-fast bacilli; a lumbar puncture should be done to measure cell counts, glucose, and protein as well as to obtain CSF for culture.