The test for bacteriuria in the Pediatric Multiphasic Health Screening Program involves collection of the specimen without prior washing, and inoculation of the culture within minutes after collection. One half of a culture plate is used for each patient, and the cultures are read at 48 hours. Fifty thousand or more colonies per milliliter is considered a positive result. Patients having a positive-reaction test have a second culture performed, with the use of "clean catch" techniques.
In over 5,000 girls, 26 (0.5%) were found to have "significant" bacteriuria confirmed on second culture. There was 80% concordance between two consecutive cultures when the first showed "significant" bacteriuria, despite the difference in methods of specimen collection. The remainder apparently represented transitory bacteriuria. "Significant" organisms on the first culture were almost always present as pure cultures, in spite of the absence of prior washing.
Allen M, Shinefield HR, Thomas BJ, Barr GD. Testing for BacteriuriaPediatric Multiphasic Health Screening Program: Report No. 4. Am J Dis Child. 1974;127(4):504–506. doi:10.1001/archpedi.1974.02110230050007