UTI 29JAN

​UTI 27JAN

By Caroline Little

Learning Objectives

Understand common clinical presentation

Recognize the risk factors

Understand the pathophysiology

Understanding lab results of Urine analysis and culture

Review antibiotic therapy choices

UTI diagnostics

Multiple Choice

Approximately how many ambulatory visits occur annually in the US for pediatric UTIs?

• 250,000

• 500,000

• 1.5 million

• 5 million

Multiple Choice

What percentage of females and males have 1 UTI by age 6 to 7?

• 3-4% females

  2-3% males

• 14-15% females

  4-5% males

• 9-10% females

  3-4% males

• 7-8% females

  1-2% males

Epidemiology

• Common infection in childhood

  • 1.5 million ambulatory visits annually

  • 50,000 inpatient hospitalizations annually

• 7-8% females and 1-2% males have a UTI by age 6-7

Multiple Choice

Which organism accounts for the majority of UTIs in children?

• Escherichia coli

• Staphylococcus saprophyticus

• Proteus mirabilis

• Enterococcus species

Less common:
Staph saprophyticus, Staph aureus, viruses, and fungi

Multiple Choice

Through which mechanism does Uropathogenic E. coli initiate cystitis?

• Formation of biofilms on catheters

• Production of urease

• Binding to bladder urothelium via type 1 pili

• Hematogenous spread to the kidney

​Pathogenesis

Open Ended

What risk factors are there for UTIs in children?

Multiple Choice

Which male population is most at risk for UTIs?

• Circumcised infant

• Uncircumcised Infant

• Toddlers

• Adolescents

Multiple Choice

Sexual activity increases UTI risk primarily through which mechanism?

• Transfer of uropathogens from the perineum into the urethra

• Changes in urine pH after intercourse

• Introduction of antibiotic-resistant organisms

• Hormonal suppression of immune defenses

Risk Factors

• Female sex

• Lack of circumcision

• Constipation

• Anatomic anomalies

• Bladder and Bowel dysfunction

• Sexual Activity

• Previous history

• Urinary catheter

​VUR

​Urinary
Tract
Dilation

Multiple Choice

What percentage of infants and toddlers presenting with fever have a UTI?

• 1%

• 7%

• 12%

• 21%

​Clinical Presentation

​UTI calc for 2-23 months for testing and treatment

• Calculates pre-test probability of UTI

  • guides decision to test

  • based on demographic and clinical factors

• Calculates post-test probability of UTI

  • guides decision to treat

  • after incorporating urinalysis results

Multiple Select

Pyuria is a hallmark of a UTI and is defined by

• Centrifuged urine >5 WBCs

• Centrifuged urine >10 WBCs

• Noncentrifued urine >10 WBCs

• Noncentrifuged urine >15 WBCs

• Leukocyte esterase on dipstick

Multiple Select

What is required to diagnose UTI for ages 2-24 months?

• urine culture >50,000 CFU/mL of uropathogen

• Urinalysis showing pyuria or bacteriuria

• Fever

• urine culture >100,000 CFU/mL of uropathogen

Multiple Choice

Which organism is least likely to produce a positive urine nitrite result?

• Escherichia coli

• Klebsiella species

• Pseudomonas aeruginosa

• Enterococcus species

Multiple Choice

Which positive finding/test is the least sensitive but most specific?

• Nitrite test

• Leukocyte esterase test

• WBCs on microscopy

Multiple Choice

Which of the following describes the relationship between delay in initiating antibiotic therapy and risk of kidney scarring in children with febrile UTIs?

• Delaying antibiotics has no impact on kidney scarring if treatment is started within 7 days

• The risk of kidney scarring increases most significantly after 48–72 hours of untreated fever

• Kidney scarring occurs only in children with recurrent UTIs

• Early antibiotics prevent scarring only in children with VUR

Multiple Choice

Which empiric oral antibiotic should be started for UTIs?

• Cephalexin

• Ceftriaxone

• Nitrofurantoin

• Amoxicillin

• Ciprofloxacin

Open Ended

What antibiotic should be avoided when treating pyelonephritis due to low renal penetration?

​Antibiotics

Multiple Choice

True or false: Cranberry juice, adequate hydration, voiding after sex, bubble baths, wiping front to back, and probiotics all help prevent UTIs.

• True

• False

Multiple Choice

Which imaging study is recommended after a first febrile UTIs in ALL infants aged 2–24 months?

• Voiding cystourethrogram (VCUG)

• Dimercaptosuccinic acid (DMSA) renal scan

• Kidney and bladder US

• CT abdomen

​RBUS

​DMSA

​VCUG

Multiple Select

A voiding cystourethrogram is recommended in children with

• abnormal KBUS

• known kidney scarring

• atypial uropathogens

• 1st Febrile UTIs

​CHOP Recommendations

Multiple Choice

True or false: Obtaining a urine culture after antibiotics therapy as a proof of cure is not recommended.

• True

• False

Multiple Choice

A 5-month-old boy is seen in clinic for 2 days of fever and decreased feeding. He seems fussier than usual, is taking 3 oz of formula per feeding rather than his usual 6 oz, and had 3 loose stools yesterday. He has had no vomiting and had 6 wet diapers in the past 24 hours. The boy is alert and active. His temperature is 39.2°C. He is an uncircumcised male with no significant findings on physical examination. After cleaning the perineum, a bag urine specimen is obtained with the following dipstick results: +Nitrites and 1+ Leukocytes. the BEST next step in this infant’s management is to

• Admit for IV Antibiotics

• 
  Obtain a specimen by urethral catheterization for urine culture

• Treat with oral cephalexin

• Order voiding cystourethrography

Multiple Choice

A 8-month-old F is seen for 2 days of fever and decreased appetite. No history of diarrhea, vomiting, cough or congestion. Her temperature is is 39.5 C and she is mildly dehydrated. A catheterized urine sample is collected. Urinalysis showed 2+ leukocyte esterase, negative nitrite, and 20-50/HPF WBCs. She is admitted for IV antibiotics. Her urine culture grows 50,000 CFU/mL of E coli. RBUS shows mild left hydronephrosis. What is the most appropriate next step?

• Perform voiding cystourethrogram

• Repeat urinalysis and culture

• Repeat renal ultrasonography after 1 month

• Repeat renal ultrasonography after 2 months

• Perform DMSA (dimercaptosuccinic acid) renal scan

Multiple Choice

A previously healthy 14-month-old girl is brought to the ED with a 1-day history of fever of 39.1°C last night. She seems to be having a normal number of wet diapers. She has not had vomiting. She has no known allergies. She is alert and her physical examination is negative for any clear source of infection. A catheterized urine specimen showed 3+ leukocyte esterase, positive nitrites, and 20 to 30 white blood cells per mm3 on an unspun specimen. Culture is pending. Which one of the following is the most appropriate therapy?

• Admit for IV antibiotics

• Admit for observation pending the culture result

• Begin oral Nitrofurantoin

• Begin oral Cephalexin

• Begin oral Amoxicillin

Multiple Choice

A 2-month-old boy is brought to the office by his parents after a recent hospitalization of a first-time febrile urinary tract infection (UTI). He was discharged to home 5 days ago on oral amoxicillin as the urine culture grew ampicillin-susceptible Escherichia coli. Mom states that he is doing well and is back to his normal self. He is uncircumcised, and his parents are opposed to having him circumcised. Renal bladder ultrasonography noted mild leftsided hydronephrosis, and a voiding cystourethrogram (VCUG) showed grade II vesicoureteral reflux on the left. Which one of the following is the most appropriate recommendation to prevent renal scarring with subsequent UTI(s)?

• Begin TMP-SMX antimicrobial prophylaxis for 12 months.

• Advise that he be brought in to be seen for any febrile illness and receive early empirical antimicrobial treatment if evaluation findings are consistent with a UTI.

• Begin azithromycin antimicrobial prophylaxis alternating with amoxicillin antimicrobial prophylaxis every 2 months.

• Schedule for surgical repair of the vesicoureteral reflux.

Multiple Choice

A 4-month-old girl is admitted to the hospital for a second febrile UTI. Her history is remarkable for hospitalization for a febrile E coli UTI at 2 months of age. Renal bladder ultrasonography with the first UTI was normal. Urine culture with the current UTI is growing extended-spectrum b-lactamase Klebsiella oxytoca. She is currently receiving IV meropenem and is now afebrile after 48 hours of treatment. Which one of the following is the most appropriate next step in management?

• VCUG

• CT abdomen

• MRI abdomen

• Dimercaptosuccinic acid renal scan

References

Barola S, Grossman OK, Abdelhalim A. Urinary Tract Infections In Children. [Updated 2024 Jan 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK599548/
Melanie C. Marsh, Guillermo Yepes Junquera, Emily Stonebrook, John David Spencer, Joshua R. Watson; Urinary Tract Infections in Children. Pediatr Rev May 2024; 45 (5): 260–270. https://doi.org/10.1542/pir.2023-006017
Kenneth B. Roberts, Subcommittee on Urinary Tract Infection, Steering Committee on Quality Improvement and Management; Urinary Tract Infection: Clinical Practice Guideline for the Diagnosis and Management of the Initial UTI in Febrile Infants and Children 2 to 24 Months. Pediatrics September 2011; 128 (3): 595–610. 10.1542/peds.2011-1330
https://publications.aap.org/pediatrics/article/128/3/595/30724/Urinary-Tract-Infection-Clinical-Practice?autologincheck=redirected
https://www.chop.edu/clinical-pathway/urinary-tract-infection-uti-clinical-pathway
https://www.childrenscolorado.org/globalassets/healthcare-professionals/clinical-pathways/urinary-tract-infection.pdf

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