Comparison between microscopical examination of unstained deposits of urine and quantitative culture.

Side-room examination of fresh samples of urine was compared with the results of surface viable bacterial counts. Examination of centrifuged deposits of urine for bacterial content was shown to compare very well with subsequent culture results. 87% of infected urines were detected, and only 6% of noninfected urines were wrongly identified. Evaluation of the uncentrifuged samples was less easy. There was poor agreement between the naked eye appearance, the presence of protein, and the pus cell count and the ultimate laboratory bacterial count. Microscopy of urinary sediments after centrifuging is recommended to assist in the rapid diagnosis of urinary tract infections particularly in young children.