Smelly urine increases likelihood of UTI

April 5, 2012

The presence of foul or strong urine odor is often taken as an indicator of urinary tract infection (UTI) in young children. A new study finds that parent report of malodorous urine increases the likelihood of infection among patients being evaluated for suspected UTI, but is the association strong enough to confirm a diagnosis?

The presence of foul or strong urine odor is often taken as an indicator of urinary tract infection (UTI) in young children. A new study finds that parent report of malodorous urine increases the likelihood of infection among patients being evaluated for suspected UTI, but is the association strong enough to confirm a diagnosis?

Previous studies have reported the value of smelly urine as a predictor of UTI in young children, but results were contradictory.

The new prospective cohort study involved 331 patients aged 1 to 36 months (median age, 12 months) in the emergency department of a pediatric hospital for whom a urine culture was prescribed for suspected UTI. Of these, 51 patients (15%) met UTI criteria.

Based on a questionnaire administered to parents, smelly urine was reported in 57% of the children with UTI and in 32% of children without UTI. On logistic regression, malodorous urine was associated with UTI, and the association remained statistically significant when adjusted for sex and the presence of vesicoureteral reflux (VUR).

The investigators noted that the association between smelly urine and UTI was at least as significant as the association with female sex, past medical history of UTI, and presence of VUR. However, 40% of children with UTI in the series did not have malodorous urine, and 30% of parents reported malodorous urine in children without UTI.

Although parent report of smelly urine increased the probability of UTI, in particular in children with fever without source (FWS), it did not have a sufficiently high specificity or sensitivity to definitely rule in or rule out a UTI.

Despite these limitations and given the clear association between this symptom and UTI, parental reporting of malodorous urine should make the clinician more suspicious of this type of infection in a young child with FWS and ask for a urine culture more rapidly than if the child did not present with this symptom, according to the researchers.

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