Specimens of urine obtained from young girls by catheter versus voiding; a comparative study of bacterial cultures, gram stains and bacterial counts in paired specimens.

The pertinent literature on bacteriologic study of the urine has been reviewed in brief. Bacteriologic studies, including cultures, Gram stains and colony counts, of catheterized and voided specimens of urine from girls aged 2 to 12 years, were carried out in three groups: Group I: paired specimens (catheter and clean voided). Group II: clean voided specimens. Group III: random non-clean voided specimens. There was a 96.5% positive correlation between catheter and clean voided specimens obtained by a standardized technique from the same patients; the time interval between the two types of examinations was less than 1 hour. Colony counts provide a valid means of differentiating infection from contamination in both clean voided and catheter specimens from female children. The data suggest that urines containing less than 1,000 colonies/ml are indicative of contamination; urines containing between 1,000 and 100,000 colonies/ml are to be suspected of infection, and urines containing more than 100,000 colonies/ml of urine are indicative of infection. Clean voided specimens are valid only if the patient is prepared before collection of the specimen as carefully as for catheterization. Where doubtful results are obtained, the study of more than one specimen of urine is absolutely necessary. In our experience, follow-up studies resolved doubtful findings in every instance. Under certain circumstances, catheterization must remain a necessary procedure in the diagnosis and management of infection of the urinary tract, with the full realization that the use of this instrumentation may involve the risk of introducing infection. Our results confirm previous findings that the presence of organisms in Gram stains in the absence of epithelial cells from catheter or clean voided specimens of urine is of diagnostic significance.