Studies in Urinary Tract Infections

Abstract

Methods for the determination of leucocyte excretion in the urine have been studied, and an investigation has been made of the relationship between pyuria and bacteriuria. All of 42 women with no evidence of urinary tract disease excreted fewer than 400,000 leucocytes per hour, while 144 out of 152 women with bacteriuria excreted more than 400,000 leucocytes per hour, regardless of the type of bacteria isolated from the urine. Among these patients the excretion rate was found to be higher in those with impaired urine concentration ability, i.e. with signs of pyelonephritis. Pyuria can be diagnosed by estimation of the leucocyte excretion rate or by determination of the leucocyte concentration in the urine. There were more than 10 leucocytes per mm3 of urine in 97% of the specimens from 164 patients who excreted more than 400,000 leucocytes per hour. Ten or fewer leucocytes per mm3 were found in the urine from 92% of the 71 subjects who had excretion rates below 400,000 leucocytes per hour. With the technique employed for microscopic examination of the urinary sediment, the finding of three or more leucocytes per high‐power field indicates pyuria; if there are fewer than three, pyuria cannot, however, be ruled out.