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

Abstract

Sterile mid stream specimens of urine (MSSU) were obtained from 84 children in a hospital outpatient department. All 84 children collected urine at home by one of two Dipslide methods and by collection into boric acid within 24 hours of the hospital collected MSSU. The samples collected at home were posted to the hospital. Thirty six of the Dipslides (43%) and nine of the boric acid samples (10%) were not sterile but none had a pure growth of a single organism of >105 organisms/ml. In addition, 17 of the Dipslides (20%) were returned with one or both media detatched and therefore could not be relied upon to exclude urinary tract infection.In a second part to the study, 95 urines which showed a significant growth in primary culture were also cultured after storage in boric acid. Inhibition was noted in nine samples after storage in boric acid, seven of which were in underfilled bottles. Transport of specimens in boric acid produced less contamination than Dipslides but may inhibit growth in a small number of specimens. Technical One hundred and seven consecutive children (age range 2-18 years) attending the outpatient renal clinic were enrolled in the study. Only continent children participated. An MSSU was obtained from all children after perineal cleansing. The parents were instructed by experienced nursing staff to clean the perineum from front to back using 0O015% chlorhexidine with 0-15% cetrimide (Savlodil, ICI). Urine was stored immediately in a preservative free sterile container at 4°C before transfer to the laboratory for microscopy and culture on the same day.Parents were instructed to clean the perineum in the same way before home urine collection. They were asked to collect the specimens on the same day as the hospital attendance. Detailed written instructions as to how to collect the samples were given to the parents in addition to a verbal explanation at the time of the clinic attendance.The following three methods were used at home. (1) Boric acid. An MSSU was collected into a sterile bowl and 5 ml poured into a bottle containing boric acid (Sterilin) to yield a 1-3% solution. (2) Dipslide 'dip'. An MSSU was collected as above and a Dipslide was dipped into this. Excess urine was allowed to drain and the Dipslide was placed in the bottle and sealed. (3) Dipslide 'stream'. The Dipslide was held in the mid portion of the urinary stream, excess urine was allowed to drain and the slide was sealed in the bottle.All children were asked to collect a boric acid sample. They were randomly allocated to collect either a Dipslide dip sample or a Dipslide stream sample in addition to this.Parents were asked to return the specimens by first class post on the day of collection. Laboratory methodsThe length of time it took for the sample to reach the laboratory was noted.Biochemical analysis for pH, protein, blood, ketones, nitrites, and glucose was performed using Multistix (Ames).

The management of urinary tract infection in children

“…Use of a Dipslide (effectively a miniature culture plate) can give a reliable positive or negative result within 24 hours4 , 27 so is especially useful for GPs at weekends. Confirmatory laboratory culture and sensitivity testing are recommended 28. A positive nitrite stick test, which depends on the ability of bacteria to convert urinary nitrate to nitrite, is a reliable test for coliform infections particularly if accompanied by a positive leucocyte esterase stick test.…”