Perineal cleansing does not reduce contamination of urine samples from pregnant adolescents.
Author(s): Schlager TA, Smith DE, Donowitz LG
Publication: Pediatr Infect Dis J, 1995, Vol. 14, Page 909-11
PubMed ID: 8584324 PubMed Review Paper? No
Purpose of Paper
This paper investigated the effects of collecting urine after perineal cleansing (clean-catch urine) rather than non-clean-catch urine on the contamination rates in matched specimens from 100 pregnant adolescents. The authors also investigated if positive urinalysis or pyuria were more common in specimens that cultured a pathogen.
Conclusion of Paper
For 87 of the 100 patients, the results were identical in the clean-catch (after perineal cleansing) and non-clean catch specimen and for 7 of the 13 discrepant cases there was no growth in the non-clean-catch specimen and non-pathogenic growth in the clean-catch specimen. The percentage of specimens considered contaminated or non-contaminated was comparable between clean-catch and non-clean-catch specimens. Importantly, positive urinalysis was not a predictor of pathogen growth but pyuria was more common in specimens that cultured a pathogen than those that had no growth.
Studies
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Study Purpose
This study investigated the effects of collecting clean-catch urine rather than non-clean-catch urine on the contamination rates in matched specimens from 100 pregnant adolescents. The authors also investigated if positive urinalysis or pyuria were more common in specimens that cultured a pathogen.
Summary of Findings:
Two consecutive urine specimens were collected during a single prenatal visit from patients aged 10-19. Women who had taken antibiotics in the prior 7 days or displayed symptoms of urinary tract infection were excluded. The first specimen was collected mid-stream without any prior cleaning into a sterile specimen container. Prior to collection of the second specimen, the patient cleaned the urethral meatus and then the peritoneum with a Castille soap towelette and then collected midstream urine into the clean-catch urine kit container. Specimens were refrigerated for up to 5 h before urinalysis using dipsticks and microscopy and bacterial culture. The authors defined a urinalysis as positive when the specimen contained bacteria and/or were positive for nitrite on the dipstick and had either more than five leukocytes/field or was positive for leukoesterase on the dipstick. Significant bacteruria was defined at ≥105 cfu/mL of a single pathogen (species of Enterobacteriaceae, Enterococcus, Staphylococcus aureus, Staphylococcus saprophyticus, or group B streptococci). Sterile urine contained <103 cfu pathogens/mL while contaminated urine contained <105 cfu/mL of pathogenic bacteria or non-pathogenic bacteria.
For 87 of the 100 patients, the results were identical in the clean-catch (collected after perineal cleansing) and non-clean-catch specimen including 33 with no growth, 44 which cultured non-pathogens, and 10 that grew the same pathogen in both specimens. The discrepant specimens included seven which had no growth in the non-clean-catch specimen but non-pathogenic growth in the clean-catch specimen, three which cultured group B streptococci in the non-clean-catch specimen but non-pathogenic growth in the clean-catch specimen, one which cultured Escherichia coli in the non-clean-catch specimen but non-pathogenic growth in the clean-catch specimen, one that cultured non-pathogenic growth in the non-clean-catch specimen but cultured group B streptococci in the clean-catch specimen, and one that cultured non-pathogenic growth in the non-clean-catch specimen but had no growth in the clean-catch specimen. Overall, 55 of the non-clean-catch specimens and 62 of the clean-catch specimens were considered contaminated (P=0.38). Similarly, 40 non-clean-catch and 34 clean-catch specimens had no growth (P=0.46). Importantly, positive urinalysis was found in 11 of 25 specimens that cultured a pathogen and 24 of 33 that were sterile (P=0.33) but pyuria was more common in specimens that cultured a pathogen than those that had no growth (32% versus 8% P=0.006) and also occurred in 17% of specimens that had non-pathogenic growth.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Other diagnoses
- Pregnant
Platform:
Analyte Technology Platform Cell count/volume Light microscopy Cell count/volume Microbiological assay Cell count/volume Colorimetric assay Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Acquisition Method of fluid acquisition Different urine collection procedures compared
Voided urine (spot collection)
Collection site preparation methods compared