We have examined the prevalence of asymptomatic bacteriuria on 4238 cases of children ages 3-15. In the first screening of our test, the presence of 104 or more organisms per milliliter of urine on the dipslide was taken as a positive finding, using the reagent strips for bacteriuria, Microstix-3(Ames.). If the first test was positive, two more tests were repeated by midstream semiquantitatively cultured at our hospital. According to the result gained in the examination, ABU was detected at the frequency of 1.5–2.0% of the examined cases, without difference of ages and sex. When we performed intravenous pyelography(IVP) on the whole detected cases of ABU, we could get abnormal findings of 49% in the 105/ml group, and 11% in the 104/ml group.
We can conclude that the most reliable method is the culture method, because ABU is rarely accompanied by abnormality of urinalysis and that chronic pyelonephritis should be prevented by the operation of mass-screening urinalysis of ABU at the age of 4-6 and the active treatment of the detected ABU.