Screening methods for covert bacteriuria in schoolgirls.

Abstract

SummaryScreening tests for bacteriuria based on two different principles were evaluated in 1582 schoolgirls aged 5-11 years, and in 26 girls aged 3-16 years attending hospital with symptomatic urinary tract infection. Tests for hypoglucosuria, performed by a semi-automated fluorometric method and with Uriglox strips on early-morning urine samples voided after overnight fasting, gave unacceptably high false-negative rates (16.70o and 20.8°O respectively).Oxoid and Uricult dipslides were immersed in fresh midstream specimens of urine obtained at school and read after overnight incubation at 37 C. Both gave comparable results, with low false-positive rates and no false-negative responses. The higher cost of screening by dipslides was halved by using the "dipstream" technique, which also gave no false-negative results. Its falsepositive rate of 13.5"O could be reduced to 1.8"(, by disregarding colony counts of 108 non-faecal organisms and over per litre, which appear unimportant in schoolchildren.Bacteriuria was found in 2.3%) of the schoolgirls; 39( of them had symptoms, compared with 7.2U, of the healthy girls, and 25) showed vesicoureteric reflux, which in 17") was associated with renal scarring. Since the natural history of covert bacteriuria and its relationChildren's Hospital, Birmingham B16 8ET

Home collection of urine specimens--boric acid bottles or Dipslides?

“…In a previous study, comparing the two ways of using the Dipslide, there was a very low contamination rate using the Dipslide dip method collected under supervision and a higher contamination rate using the stream method unsupervised at home. 7 Our results suggest that possibly there is less contamination using the stream method when both methods are compared under the same circumstances, although our results only just reach significance. The parents in our study were commit-ted people who agreed to take part in a research protocol.…”

Urinary infections in children 1985

“…Repeated screening of cohorts of the same population of girls between 6 and 12 years showed an annual increment with a cumulative incidence during school age of 5%. Further screening of schoolgirls for bacteriuria was carried out in Britain, notably in Dundee, Oxford and Cardiff, Newcastle and Birmin-gham (Savage et al, 1969;Asscher et al, 1973;Newcastle Asymptomatic Bacteriuria Research Group, 1975;Edwards et al, 1975). The prevalence and other findings were broadly similar to that of Kunin.…”

Management of urinary tract infection.

“…Unfortunately, there are no simple 'dipstick' tests that are completely reliable; those based on bacterial consumption of the already minimal urinary glucose concentrations, or on conversion of urinary nitrate to nitrite, can be taken as good evidence of UTI when they yield positive results but unfortunately have unacceptably high false negative rates. 6 The most widely used cultural method is the viable colony count, which relies on the fact that bacteria incubated in the bladder urine at body temperature will have multiplied many times in two to three hours, whereas contaminant bacteria washed off the genitalia during voiding will not. A significant colony count is >105/ml; borderline counts of 104-105/ml can be regarded as unimportant if there is a mixed growth but may require repetition if associated with a single pathogen.…”

“…Provided that the genitalia are clean, antiseptic swabbing is unnecessary. 6 Information obtained from mothers often reveals that the specimen has been carefully collected at home at 0730h, reaches the doctor's surgery by 0900h, and is later despatched to the local hospital laboratory, so that a delay of some three hours is not uncommon. Contaminant bacteria will continue to proliferate at room temperature to yield borderline or even 'significant' counts and, as they are enterobacteria themselves, distinction from true bacteriuria may be impossible.…”