Presented by Alex Henri MD
How prone are UA’s to contamination, can we identify contamination on a UA, and does contamination matter?
How common is contamination?
- “Growth of bacteria on culture without bacteria in the urinary tract.”
- Contamination rates for clean-catch urinalysis in children vary by study: 2% – 39%
Is this contamination?
“Contamination can be identified unequivocally only by demonstrating that urine collected by suprapubic aspiration is sterile whereas a midstream urine culture grows one or more organisms.” (Stamm, 1983.)
What is the probability of true bacteriuria in symptomatic and asymptomatic patients based on +UA signs?
If a culture does grow bacteria, would we do anything about it?
“True infection without pyuria is unusual, but pyuria can occur in the absence of apparent bacterial infection”
- Contamination of the urine sample by the sterilizing solution used to clean the meatus
- Contamination of the urine sample with vaginal leukocytes from vaginal secretions
- Chronic interstitial nephritis
- Uroepithelial tumor
- Interstitial cystitis
- Intra-abdominal inflammatory process adjacent to the bladder
- Infection with atypical organisms, such as Chlamydia, Ureaplasma urealyticum, or tuberculosis
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