The overall prevalence of UTI is approximately 2.1 percent in febrile infants but varies widely by race and sex.

Caucasian children have a two- to fourfold higher prevalence of UTI as compared to African-American and Hispanic children

Females have a two- to fourfold higher prevalence of UTI than do males

Caucasian females with a temperature of 39 ºC have a UTI prevalence of 13 percent

Most common source of serious bacterial infection in children < 2 years

It is a diagnostic challenge by history and physical exam alone

Infants less than 2 years have non specific symptoms

Easy Quick to perform Inexpensive

Common practice › young febrile infants who do not have an obvious

source of infection

Requires an invasive procedure.

Comparison of rapid tests and screening strategies for detecting UTI in infants

Cross-sectional study 3873 children <2 years of age who had a urine

culture obtained in the ED by urethral catheterization

Urine dipstick tests leukocyte esterase or nitrites

Enhanced urinalysis (UA) (urine white blood cell count/mm3 plus

Gram stain) Compared with urine culture results

Test positive for nitrite and leucocyte › Specificity of 97%

Test negative for nitrite, LE › Sensitivity of 80%

However, the enhanced UA was the most sensitive (97%) at detecting UTI

Enhanced UA is the preferred method

Clinical Scenario

A 15 month old female presents with a 2 day history of fever to 40 degrees Celsius and mild URI symptoms. Otherwise she appears healthy.

You suspect a possible UTI. The parents are concerned about the invasiveness of a urine catheterization and do not want to cause harm to their child if the odds of an infection are low.

What are your options at this point? Can you do a bag U/A as a screen?

Retrospective Study Children younger than 2 years with fever (38°C)

seen in the emergency department during a period of 65 months

Clinical situation that necessitates the collection of a urine culture

Medical records of 37,450 febrile children

younger than 2 years were reviewed Forty-four percent were females

Median age was 10.6 months Median temperature was 38.8°C

The sensitivity of the UA was 82% The specificity of UA was 92% A negative UA result decreases the odds of a UTI

5-fold

If the Prevalence of UTI is less than 2% The risk of missing a UTI because of a false-negative UA result is "acceptable.

1 UTI would be missed for every 250 febrile infants screened by UA

Age and Sex Males younger than 6 months 5.8% Males older > than 6 months .6%

Females younger than 1 year 3.1 %

Ethnicity White Females 5% Hispanic Males 2.2%

Temperature greater than or equal to 39°C Females 3.8%

A 5 month male presents with a 2 day history of fever to 38 degrees Celsius and mild URI symptoms. Otherwise he appears healthy.

Prevalence is 3 %

Urine Culture should be obtained

A 7 month male presents with a 2 day history of fever to 38 degrees Celsius and mild URI symptoms. Otherwise he appears healthy.

Prevalence is .6 %

Consider pre-screening with a Bag UA?

A 15 month old white female presents with a 2 day history of fever to 38 degrees Celsius and mild URI symptoms. Otherwise she appears healthy.

Prevalence is 3.1 %

Urine Culture should be obtained

A 15 month old Hispanic or black female presents with a 2 day history of fever to 38 degrees Celsius and mild URI symptoms. Otherwise she appears healthy

Prevalence .2 %

Consider pre-screening with a Bag UA?

Summary

This study suggest that dipstick UA can be used as a screening tool

Offers a recommendation based on prevalence as to when to obtain a urine culture.

If the Prevalence of UTI is less than 2% The risk of missing a UTI because of a false-negative UA result is "acceptable

These patients can then be excluded from further investigation, without the need for confirmatory culture

References

Bachur R, Harper MB. Reliability of the urinalysis for predicting urinary tract infections in young febrile Division of Emergency Medicine, Arch Pediatr Adolesc Med. 2001 Jan;155(1):60-5.

Shaw KN, Gorelick M, McGowan KL, Yakscoe NM, Schwartz JS. Prevalence of urinary tract infection in febrile young children in the emergency department. Pediatrics. 1998 Aug; 102(2):e16.

Shaw KN, Gorelick M. Urinary tract infection in the pediatric patient. Pediatr Clin North Am. 1999 Dec;46(6):1111-24, vi.

Hoberman A, Urinary tract infections in young febrile children. Pediatr Infect Dis J. 1997 Jan; 16(1):11-7.

Schlager TA. Urinary tract infections in children younger than 5 years of age: epidemiology, diagnosis, treatment, outcomes and prevention. Paediatr Drugs 2001; 3(3):219-27.