A comparison of quantitative methods in the investigation of urinary infections.

Bacterial colony counts and urinary white and non-squamous epithelial cell excretion rates have been compared in successive urine samples from 51 hospital patients. In all 19 cases with a colony count greater than 100,000/ml. the cell excretion rate was over 200,000/hour. Urinary cell concentrations correlate poorly with both colony counts and the cell excretion rate. It is concluded that simple culture of a properly taken urine sample combined with a measurement of the urinary cell excretion rate is adequate for the detection of most urinary infections. In the few instances where these methods do not provide a clear-cut result, colony counting techniques may be of value.