A simplified accurate method for detecting bacteriuria

Abstract

The accuracy of detecting bacteriuria by a combination of the Griess nitrite and diphenylamine tests was compared with standard colony counting methods in 624 asymptomatic pregnant patients. The chemical procedures were performed on first morning voided urine and colony counts were performed on cleanly caught midstream urine samples. In each of the 564 urine samples which were Griess negative and diphenylamine positive, the colony count was negative; whereas, in each of the 7 which were Griess positive and diphenylamine negative the colony count was positive. The chemical combinations in the 53 remaining urine samples did not correlate with the bacteriologic findings. This combination of chemical tests separated the 624 patients into three distinct groups: 564 without bacteriuria, 7 with bacteriuria, and 53 uncertain. There were no false negative or false positive results. A 90 per cent reduction in work load resulted without fear of false negative results.