Abstract

Urine culture is of little value unless it is done quantitatively on a freshly-voided, clean-catch specimen, or one taken directly from the bladder. Active urinary infection is usually accompanied by bacterial colony counts of 100,000 or more per ml of urine. Carefully taken specimens from an uninfected urinary tract will seldom give counts above 10,000 per ml. Colony counts of a potential pathogen in numbers less than 10,000 per ml can only be regarded as equivocal, calling for a second specimen if treatment has not yet been started. Assessments based on 2 or 3 successive cultures may be more helpful, but in infants and small children suprapubic bladder aspiration may be necessary to settle the issue.