To the Editor.—
We enjoyed reading the article by Komaroff et al in the July Archives (138:1069-1073, 1978) and agree that the urinalysis, particularly the examination for bacteriuria, can be helpful in discriminating between a urinary tract infection and vaginitis. In their study, Kunin's criterion1 was used, which considers the counting of one to ten bacteria in an unstained urine sediment in a high-power dry microscopic field as a positive result. With 105/cc bacteria denoting an important level of bacteriuria, Kunin's method results in approximately 12% false-positives and about that many false-negatives.We favor checking for bacteriuria in an unspun urine specimen stained with methylene blue. This technique eliminates variabilities of urine centrifugation and affords better visualization of bacilli; the dye aids in distinguishing cocciform bacteria from urinary debris.1 Approximately 1/30,000 cc is contained in one highpower field, so that seeing one bacterium per field correlates
Hashimoto F, Reed W, Chongsiriwatana K. Urinalysis for Bacteriuria. Arch Intern Med. 1979;139(10):1193–1194. doi:10.1001/archinte.1979.03630470101035
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