Urinary tract infection in children – 15 Interesting Facts

How common is Urinary tract infection in children

A urinary tract infection (UTI) is an infection of any part of the urinary tract, which includes the kidneys, ureters, bladder, and urethra. These organs make, store, and get rid of urine in the body.

An upper UTI affects the ureters and kidneys (pyelonephritis), and a lower UTI affects the bladder (cystitis) and urethra (urethritis).

Interesting Facts

  1. Urinary tract infection in children may present with fever alone; however, it may present with nonspecific signs such as poor feeding, vomiting, fussiness, and absence of fever
  2. Older children present with symptoms including urinary frequency, urinary dysuria, and abdominal pain
  3. Fever with infection in a child of any age prompts suspicion for pyelonephritis
  4. Children at highest risk are young girls and uncircumcised boys
  5. Risk factors include fever (higher than 39°C and without another source on physical examination), white race, constipation, earlier history of infection, history of vesicoureteral reflux, or anatomic abnormality of urinary tract or neurogenic bladder
  6. Adolescents who are sexually active or have sexually transmitted diseases have higher associations with urinary tract infection
  7. Physical examination findings consistent with urinary tract infection include fever (higher than 39°C) and suprapubic tenderness; costovertebral angle tenderness is consistent with pyelonephritis
  8. To establish definitive diagnosis in young children, urine should show evidence suggesting infection (ie, pyuria and/or bacteriuria) and positive urine culture result
  9. Obtain urine specimen for culture only by catheterization or suprapubic aspiration in non–toilet-trained children (usually aged 24 months or younger); clean-catch urine is acceptable for toilet-trained children
  10. In general, urine culture results diagnostic in children are as follows: growth of single organism to more than 100,000 CFU/mL on clean-catch specimen, more than 50,000 CFU/mL on catheter specimen, and any growth on suprapubic specimen 1
  11. Escherichia coli is the most frequent pathogen; in general, a third-generation cephalosporin is a good choice for empiric antibiotic, depending on patient-specific factors and local sensitivities
  12. Oral antibiotics are as effective as parenteral antibiotics for treatment of cystitis or pyelonephritis in children older than 1 month
  13. Children with the initial diagnosis of uncomplicated infection should clinically respond to antibiotics within 24 to 48 hours with improved symptoms and defervescence; failure to respond within 48 hours indicates a complicated course (ie, presence of renal abscess, obstructive uropathy, vesicoureteral reflux, alternate diagnosis) or pathogen not covered by empiric antibiotic
    • Further work-up, ultrasonography, and broadening of antibiotic coverage are indicated
  14. Renal ultrasonography is recommended for follow-up study in children to evaluate for signs of vesicoureteral reflux or any other abnormalities that place the child at increased risk for future infection
    • Perform bladder and renal ultrasonography in children younger than 2 years after first febrile infection and in all children with recurrent infection
  15. Most children have no long-term sequelae; chronic renal insufficiency requiring transplant is extremely rare

What are the causes?

Most urinary tract infections are caused by bacteria in the genital area, around the entrance to the urinary tract (urethra). These bacteria grow and cause irritation and inflammation of the urinary tract.

What increases the risk?

This condition is more likely to develop if:

  • Your child is a boy and is uncircumcised.
  • Your child is a girl and is 4 years old or younger.
  • Your child is a boy and is 1 year old or younger.
  • Your child is an infant and has a condition in which urine from the bladder goes back into the tubes that connect the kidneys to the bladder (vesicoureteral reflux).
  • Your child is an infant and he or she was born prematurely.
  • Your child is constipated.
  • Your child has a urinary catheter that stays in place (indwelling).
  • Your child has a weak disease-fighting system (immunesystem).
  • Your child has a medical condition that affects his or her bowels, kidneys, or bladder.
  • Your child has diabetes.
  • Your older child engages in sexual activity.

What are the signs or symptoms?

Symptoms of this condition vary depending on the age of the child.

Symptoms in younger children

  • Fever. This may be the only symptom in young children.
  • Refusing to eat.
  • Sleeping more often than usual.
  • Irritability.
  • Vomiting.
  • Diarrhea.
  • Blood in the urine.
  • Urine that smells bad or unusual.

Symptoms in older children

  • Needing to urinate right away (urgently).
  • Pain or burning with urination.
  • Bed-wetting, or getting up at night to urinate.
  • Trouble urinating.
  • Blood in the urine.
  • Fever.
  • Pain in the lower abdomen or back.
  • Vaginal discharge for girls.
  • Constipation.

How is this diagnosed?

This condition is diagnosed with a medical history and physical exam. Your child will also need to provide a urine sample. Depending on your child’s age and whether he or she is toilet trained, urine may be collected by:

  • Clean catch urine collection.
  • Urinary catheterization.

Other tests may be done, including:

  • Blood tests.
  • Sexually transmitted disease (STD) testing for adolescents.

If your child has had more than one UTI, a cystoscopy or imaging studies may be done to determine the cause of the infections.

How is this treated?

Treatment for this condition often includes a combination of two or more of the following:

  • Antibiotic medicine.
  • Other medicines to treat less common causes of UTI.
  • Over-the-counter medicines to treat pain.
  • Drinking enough water to help clear bacteria out of the urinary tract and keep your child well hydrated. If your child cannot do this, fluids may need to be given through an IV.
  • Bowel and bladder training.

Follow these instructions at home:

  • Give over-the-counter and prescription medicines only as told by your child’s health care provider.
  • If your child was prescribed an antibiotic medicine, give it as told by your child’s health care provider. Do not stop giving the antibiotic even if your child starts to feel better.
  • Have your child drink enough fluid to keep his or her urine pale yellow.
  • Keep all follow-up visits as told by your child’s health care provider. This is important.
  • Encourage your child:
    • To empty his or her bladder often and not to hold urine for long periods of time.
    • To empty his or her bladder completely during urination.
    • To sit on the toilet for 10 minutes after breakfast and dinner to help him or her build the habit of going to the bathroom more regularly.
  • After urinating or having a bowel movement, your child should wipe from front to back. Your child should use each tissue only one time.

Contact a health care provider if:

  • Your child’s symptoms have not improved after you have given antibiotics for 2 days.
  • Your child’s symptoms go away and then return.

Get help right away if:

  • Your child has a fever.
  • Your child has severe back pain or lower abdominal pain.
  • Your child is vomiting.
  • Your child who is younger than 3 months has a temperature of 100.4°F (38°C) or higher.

Summary

  • A urinary tract infection (UTI) is an infection of any part of the urinary tract, which includes the kidneys, ureters, bladder, and urethra.
  • If your child was prescribed an antibiotic medicine, give it as told by your child’s health care provider. Do not stop giving the antibiotic even if your child starts to feel better.
  • Keep all follow-up visits as told by your child’s health care provider.

Detailed Information

Pitfalls

  • Frequently presents with fever and no other symptoms; obtain urine studies in any febrile child at high risk for infection
  • Presence of alternate source of fever on examination does not exclude the possibility of infection; urinary tract infection is a lower risk but can occur concurrently 2
  • Sexually active adolescent girls with urinary symptoms consistent with infection (especially sterile pyuria) should be tested for sexually transmitted diseases (eg, chlamydia, gonorrhea, trichomoniasis) 3
  • Bag urine specimens should not be used for culture owing to unacceptably high false-positive rates
  • Do not treat child with empiric antibiotics for a urinary tract infection without a urine culture 4 5 6
    • Most guidelines stress importance of obtaining accurate result to ensure adequate antibiotic therapy based on culture susceptibility results 4 5 6 7
    • Will help avoid unnecessary referrals, radiographic evaluation, and prolonged antibiotic use

Urgent Action

  • Must be identified and treated promptly to minimize risk of renal abscess, sepsis, and renal parenchymal damage
  • All febrile children aged 60 days or younger require evaluation for urinary tract infection, even if another fever source is apparent upon examination (eg, respiratory syncytial virus–positive bronchiolitis)
  • In children who appear very ill and require immediate antibiotics, obtain urine specimen before starting antibiotics (to hold for culture and studies)

Terminology

Clinical Clarification

  • Urinary tract infection in children is uropathogen-caused inflammation of the urinary tract
  • Asymptomatic bacteriuria is not considered a urinary tract infection

Classification

  • Based on location 8
    • Lower urinary tract infection, also known as bladder infection or cystitis
    • Upper urinary tract infection, also known as kidney infection or pyelonephritis
      • Typically begins as a lower urinary tract infection, then ascends to the kidneys
      • Associated with higher risk for short-term complications (eg, renal abscess) and long-term complications (eg, renal parenchymal scarring, hypertension)
  • Based on complexity
    • Uncomplicated: infection in a patient with normal urinary tract, normal renal function, and competent immune system 9
    • Complicated
      • Associated with increased risk of acquiring bacteria and decreased efficacy of therapy
        • Urinary tract abnormalities 8 (eg, posterior urethral valves, obstruction)
          • Bladder abnormalities
            • Neurogenic bladder (urinary retention/stasis)
            • Vesicoureteral reflux
            • Indwelling bladder catheter
          • Renal or ureteral anomalies (eg, nephrolithiasis)
        • Physiologic abnormalities (eg, immunocompromised state, diabetes)
        • Infection from multidrug-resistant bacteria or unusual pathogen
        • Some sources consider any infection in newborns and any pyelonephritis to be complicated urinary tract infections 9

Diagnosis

Clinical Presentation

History

  • Symptoms in non–toilet-trained children (generally younger than 2 years) 1
    • Usual presentation is with fever and/or nonspecific symptoms 10
      • Fever
        • May not be present early in the course of disease
        • Fever (38°C or higher) lasting longer than 2 days without a known source for fever on physical examination increases likelihood of urinary tract infection 1
          • Prevalence of the disease in infants with a suspected cause of fever (38.3°C or higher) on examination is about 3% 2
          • Prevalence without a suspected cause of fever is about 6% to 8% 2
        • Fever (39°C or higher) of any duration increases likelihood of urinary tract infection 1
      • Nonspecific symptoms
        • Poor feeding
        • Decreased urine output
        • Increased sleep/lethargy
        • Fussiness
        • Vomiting, diarrhea, and abdominal pain
      • Possible urinary symptoms 3
        • Hematuria
        • Malodorous urine 8
  • Symptoms in older, verbal children 1
    • Urinary symptoms (typically present) 10
      • Dysuria
      • Frequency
      • Urgency
      • New-onset incontinence (often nocturnal)
      • Nocturia
      • Hematuria
    • Abdominal pain (sometimes present)
      • Suprapubic abdominal pain or flank/back pain
    • Fever (sometimes present)
    • Adolescents may have vaginal discharge if urinary tract infection is associated with unrecognized sexually transmitted disease
  • Fever (higher than 39.5°C) in any age group is the best clinical predictor of renal parenchymal involvement 5
    • In general, older children with cystitis present with suprapubic pain, voiding discomfort, and absence of fever 10
    • Fever (especially if high or associated with flank pain and/or vomiting) suggests pyelonephritis 10
  • Other
    • Child may have earlier history of urinary tract infection
    • Symptoms of bowel dysfunction may be associated, including: 5
      • Constipation
      • Encopresis
      • Withholding behaviors
    • Symptoms of bladder dysfunction may be associated, including: 5
      • Incontinence
      • Ineffective emptying of the bladder, which can cause urinary frequency, urgency, and dribbling
      • Prolonged voiding intervals
      • Perineal or penile pain
      • Voiding difficulties
    • Sexual activity is a risk factor for adolescents
    • Recent antibiotic use raises suspicion for the possibility of a resistant bacterial pathogen in association with the disease
    • Patients with earlier medical history significant for spinal cord anomaly, diabetes, or immunosuppression have increased risk

Physical examination

  • Vital signs
    • Fever
      • May or may not be present early in the course of disease
      • Should raise concern for pyelonephritis
        • Inflammation or infection of the kidneys is present in approximately 60% of children with febrile urinary tract infection 11
    • Blood pressure
      • Elevated blood pressure relative to age raises concern for chronic renal disease or renal parenchymal scarring
    • Growth parameters
      • Signs of failure to thrive in infants or younger children are concerning for chronic or recurrent urinary tract infections
  • Abdomen
    • Suprapubic tenderness
    • Costovertebral angle tenderness
    • Suprapubic mass (distended bladder)
    • Mobile hard abdominal mass (palpable hard stool)
  • Genitalia
    • Uncircumcised boys younger than 1 year (especially younger than 3 months) are at higher risk 11
    • Vaginal discharge associated with a sexually transmitted disease will increase likelihood of urinary tract infection
  • Neonates may present with jaundice (unconjugated/indirect or conjugated/direct hyperbilirubinemia) 1
    • Direct hyperbilirubinemia is more likely if the onset of jaundice occurs in association with urinary tract infection presenting after 8 days of life 12
    • 7.5% of neonates with jaundice who are otherwise asymptomatic have a urinary tract infection 11
  • Presence of alternative source of fever upon examination suggests that urinary tract infection is less likely, but it does not completely exclude the possibility of urinary tract infection; such alternative sources can include: 4 6
    • Gastroenteritis
    • Bronchiolitis
    • Upper respiratory tract infection
    • Croup
    • Viral stomatitis
    • Otitis media
    • Meningitis

Causes and Risk Factors

Causes

  • Bacteria 1
    • Escherichia coli is most common, responsible for about 50% to 80% of pediatric cases 10 12
      • Infants with vesicoureteral reflux are more likely to present with urinary tract infection from non–Escherichia coli pathogens 11 12
    • Common gram-negative organisms 3 10
      • Proteus species
      • Klebsiella species
      • Pseudomonas species
      • Enterobacter species
      • Citrobacter species
    • Common gram-positive organisms
      • Group B streptococcus (in neonates)
      • Enterococcus species
      • Staphylococcus saprophyticus
        • Most common gram-positive pathogen in an adolescent girl
      • Staphylococcus aureus (less frequent)
    • Most common pathogens in children requiring admission include the following: 3
      • Escherichia coli
      • Enterococcus species
    • Common bacterial contaminants of urine specimen (ie, skin flora organisms not considered pathogens) in otherwise healthy children 1 8
      • Lactobacillus species
      • Corynebacterium species
      • Coagulase-negative staphylococci
      • α-Hemolytic streptococci
      • Micrococcus species
  • Fungi
    • In general, fungi are uncommon causes of treatable infection. They are present as potential pathogens in children with significant comorbid medical problems, including: 1 12
      • Prematurity
      • Diabetes
      • Immunocompromised state
      • Bladder catheters
      • Long-term antibiotic use
    • Many types of fungi asymptomatically colonize and do not create infection (eg, Candida species)
  • Viruses
    • Uncommonly cause cystitis in children and include:
      • Adenovirus
      • Coxsackievirus
      • Echovirus
      • Enterovirus

Risk factors and/or associations

Highest-risk populations

  • Uncircumcised boys from birth to 3 months with fever (higher than 38°C) have a reported rate of approximately 21% 12
  • White girls younger than 2 years with fever (39°C or higher) have a reported rate of up to 16% 1
Age 1
  • Overall, 75% of urinary tract infections occur in first 2 years of life 13
    • Peak incidence is in first year of life and between second and fourth years
    • Infrequent occurrence after age 6 years unless associated with dysfunctional elimination
    • Up to 3% of boys and 10% of girls will have at least 1 urinary tract infection before age 16 years 3 10
  • Higher prevalence in the following populations:
    • Girls younger than 4 years 10
    • Boys aged 1 year and younger 14
      • Uncircumcised boys have a much greater risk of urinary tract infection compared with circumcised boys (increase has been reported as 4-fold to 20-fold) 4 6
    • Sexually active adolescent girls 15
Sex
  • Girls older than 3 months have 2- to 4-fold higher prevalence than boys 10
  • Neonatal boys have higher prevalence than neonatal girls 13
Genetics
  • Family history may be positive for pyelonephritis 16
  • No increased risk of cystitis noted with positive family history 16
Ethnicity/race
  • White children are most commonly affected, followed by Hispanic children; black children are the least affected 3
  • Prevalence of urinary tract infections is 2 times higher in white children than in black children 1
Other risk factors/associations
  • Vesicoureteral reflux 1
    • Prevalence in neonates and infants younger than 4 months with urinary tract infection is estimated at up to 43% 5 11
  • Uncircumcised penis
    • Increases risk (increase has been reported as 4-fold to 20-fold) 4 6
  • Prematurity
    • Up to 20% prevalence in febrile infants with low birth weight and in premature neonates 11
  • Maternal urinary tract infection during pregnancy 12
    • Associated with 5 to 6 times higher risk of infection in neonates 12
  • Obstructive uropathies (abnormalities that result in obstruction of urine flow and urinary stasis): 1
    • Anatomic
      • Posterior urethral valves
      • Ureteropelvic junction obstruction
      • Urethral stricture
      • Neonates with infection have the highest prevalence of renal structural abnormalities 13
    • Neurogenic
      • Congenital and acquired abnormalities of spinal cord
        • Neurogenic bladder
        • Myelomeningocele
    • Functional
      • Bowel or bladder dysfunction (eg, constipation)
  • Acquired risk factors
    • Earlier history of urinary tract infection
      • Younger age at first infection is associated with increased risk of recurrence
        • Risk of recurrence is highest in the first 6 months of life 12
    • Nephrolithiasis
    • Sexually transmitted disease
    • Sexual activity in adolescents or childhood sexual abuse 10
    • Spermicide use in sexually active females 15
    • Indwelling urinary catheters or intermittent bladder catheterization
    • Immunosuppression
    • Diabetes
    • Invasive devices (eg, IVs, drains, catheters), previous broad-spectrum antibiotic exposure, and systemic immunosuppression are associated with fungal urinary tract infections

Diagnostic Procedures

Primary diagnostic tools

  • History and physical examination in most cases can suggest diagnosis; positive urine dipstick and/or microscopy suggest presumptive diagnosis; urine culture is the gold standard to confirm diagnosis 10
    • Fever may be the only presenting symptom in young children, but it may also be absent
    • Delay in testing and subsequent treatment in young children is associated with increased risk of permanent renal scarring 17
  • Indications to test in children are based on clinical judgment and assessment of individual risk factors
    • American Academy of Pediatrics guidelines assist with decision making for younger age groups 4 6
      • Most infants younger than 60 days with fever (higher than 38°C) require full septic work-up including all of the following:
        • Blood work
        • Spinal fluid analysis
        • Catheterized or suprapubic urine specimen for urinalysis, microscopic analysis, and urine culture
      • Children aged 2 to 24 months 4 6
        • Risk factor assessment is required to determine likelihood of infection (ie, pretest probability); if there is no apparent source of fever and child is not at low risk, obtain a urine specimen for urinalysis, microscopic analysis, and culture
        • Baseline risk is approximately 5% in a child with no apparent source of fever discovered through history or physical examination 4 6
          • Presence of known source of fever diminishes the risk by one-half 4 6
        • Febrile girls have 2 times higher risk than boys; uncircumcised boys have much higher risk than circumcised boys 4 6
        • Factors associated with increased risk are additive: each individual risk factor further increases the probability of urinary tract infection and decreases test threshold 4 6
          • Girls 4 6
            • White race
            • Younger than 12 months
            • Fever (39°C or higher)
            • Fever lasting at least 2 days
            • No other cause of infection identified
          • Boys 4 6
            • Race other than black
            • Uncircumcised
            • Fever (39°C or higher) lasting longer than 24 hours
            • No other cause of infection identified
  • Presumptive diagnosis requires the presence of positive urinary dipstick findings (ie, leukocyte esterase or nitrite) and/or positive urine microscopy 18 (ie, bacteriuria 18 or pyuria 4 6)
    • Rapid screening tests (urine dipstick and urinalysis) help identify children who require empiric treatment pending urine culture result
  • Urine culture is the gold standard to confirm urinary tract infection but is not readily available for 24 to 48 hours after initial evaluation 1
    • Urinalysis must show signs of urinary tract inflammation (ie, pyuria and/or bacteriuria) and confirm bacteriuria by positive urine culture result in an appropriately collected specimen to definitively diagnose infection 4 6
  • Early ultrasonographic imaging
    • Imaging is usually not necessary to diagnose a urinary tract infection in the acute setting if there are no concerns for renal abscess or other complications 4 6
    • Indications for early ultrasonography to assess for complications (eg, abscess, pyonephrosis, obstruction) and differentiate between complicated and uncomplicated infection include:
      • Atypical presentation or severe illness 19
      • Concern for urosepsis or proven, concurrent bacteremia 18
      • Concern for urinary retention (eg, poor urine output, abdominal mass) 13 18
      • Raised creatinine level 13 or significant electrolyte derangement 18
      • Significant pain or hematuria
      • No appropriate response to antibiotics within 48 hours or with growth of non–Escherichia coli uropathogen 13 18
  • Serum laboratory tests and blood cultures do not usually help diagnose urinary tract infection but are indicated for patients who appear severely ill (tests include CBC with differential and levels of electrolytes, BUN, creatinine, C-reactive protein, and procalcitonin)
    • Most biomarkers of inflammation (eg, WBC count, C-reactive protein level) have not been shown to be reliably useful in differentiating pyelonephritis from cystitis in children
      • Elevated procalcitonin level more than 0.5 ng/mL may be suggestive of renal parenchymal involvement 18
    • In general, obtaining blood cultures for healthy patients older than 2 months in the setting of febrile urinary tract infection is not clinically useful 10
      • Bacteremia is cleared by antibiotics regardless of route of administration and organism is invariably the same as what is obtained with urine specimens
  • Special populations with urinary tract infection 3
    • Sexually active adolescent girls
      • Test for sexually transmitted diseases (especially when patient presents with sterile pyuria)
        • Pelvic examination with DNA probes for chlamydia, gonorrhea, and trichomoniasis if clinically indicated
        • DNA probes can be used on urine if pelvic examination is not clinically indicated
    • Neonates (younger than 1 month)
      • At high risk for bacteremia (risk approximately 6%-36%) 13 and meningitis (1.5%) compared with other age groups 12
      • Investigations for sepsis include blood culture and spinal fluid culture 11
  • Follow-up imaging after confirmed urinary tract infection
    • Common modalities include:
      • Ultrasonography
        • Primarily to assess for urinary tract structural abnormalities 18
        • Obtain follow-up bladder and renal ultrasonography after a first febrile urinary tract infection in children younger than 24 months 4 6
        • Obtain follow-up bladder and renal ultrasonography after any recurrent urinary tract infection if not obtained with initial infection
      • Voiding cystourethrography
        • Primarily to evaluate for vesicoureteral reflux 18
        • Obtain if screening ultrasonogram shows hydronephrosis, renal scarring, or findings suggestive of high-grade vesicoureteral reflux or obstructive uropathy 4 6
        • Obtain in infants and children younger than 24 months presenting with atypical or complex clinical circumstances 4 6
        • Obtain in infants and children younger than 24 months if there is recurrence of febrile urinary tract infection 4 6
      • Nuclear cystography
        • Alternate test of choice to evaluate for vesicoureteral reflux; preferred by some experts to evaluate such reflux in girls
        • Consider in addition to ultrasonography in the follow-up evaluation of children with complicated or recurrent urinary tract infection 13
      • Renal scan with radiolabeled succimer (dimercaptosuccinic acid)
        • Primary use is to assess for renal parenchymal abnormalities 18
        • Consider when clinical concern exists for reduced renal function 18
        • Consider, in addition to ultrasonography, in the follow-up evaluation of children with complicated or recurrent urinary tract infection 13
  • Additional guideline recommendations for diagnosis and follow-up imaging of pediatric urinary tract infection are available
    • National Institute for Health and Care Excellence guidelines (updated in 2018) 19
    • European Society for Paediatric Urology and European Association of Urology joint guidelines (updated annually) 9
    • Australasian guidelines (updated in 2014) 18 20
    • Canadian 2014 guidelines (reaffirmed in 2017) 21
    • International Children’s Continence Society 2012 recommendations 22
    • American Academy of Pediatrics 2011 guidelines (reaffirmed in 2016) 4 6

Laboratory

  • Urine specimen collection techniques 4 6
    • Obtain urine specimen for culture only by urethral catheterization or suprapubic aspiration in non–toilet-trained children (typically, from birth to 24 months of age)
    • Suprapubic aspiration with ultrasonographic guidance is considered the method of choice, although urethral catheterization yields reliable results and is better tolerated
    • Clean-catch urine is acceptable for toilet-trained children
    • Bag specimen
      • Urine collected by bag specimen has unacceptably high false-positive rates on urinalysis and urine culture owing to skin flora contamination
        • Dipstick test results are reliable only when they yield negative results 9
      • May be used in low-risk populations for screening urinalysis only
        • Closely monitoring child without further testing is an option if all the following are true (however, urinary tract infection is not 100% excluded by this practice): 4 6
          • Child has low risk
          • Child is not receiving antibiotics
          • Bag specimen test results are negative
      • Must be less than 1 hour old and rapidly processed in laboratory to maintain accuracy of testing
      • Culture from bagged specimen cannot be used to reliably confirm a urinary tract infection 1
      • If any screening studies are positive on bag specimen, urine must be obtained from urethral catheterization or suprapubic aspiration for culture and repeat urinalysis before start of empiric antimicrobial therapy 4 6
  • Urinalysis 4 6
    • Indications include symptoms of urinary tract infection and fever without a known source in at-risk, non–toilet-trained children
    • Dipstick urinalysis is the most common initial laboratory test, although urgent microscopic urinalysis should be used to confirm findings, particularly in younger children
    • Dipstick tests 1
      • Leukocyte esterase
        • Distinguishes asymptomatic bacteriuria from urinary tract infection 4 6
          • Patients with asymptomatic bacteriuria typically have negative test results 4 6
        • Indicates presence of lysed granulocytes and suggests inflammation in urine; thus, an indirect marker of pyuria 12
        • Less useful in infants because they empty their bladders more frequently 12
        • Sensitivity is 79% to 94%; specificity is 72% to 87% 4 6
          • Results may be negative very early in infection 12
          • Low specificity makes false-positive results common 4 6
            • Sometimes seen in patients with WBC presence in urine due to various conditions, including: 4 6
              • Gastroenteritis
              • Appendicitis
              • Noninfected renal stones (reactive inflammation)
              • Kawasaki disease
              • Streptococcal infections or perineal inflammation
              • Fever
              • Recent strenuous exercise
      • Nitrites
        • Marker of by-products from uropathogenic gram-negative bacteria (except Pseudomonas species); indirect marker of bacteriuria 3 4 6
        • Urine must be present in bladder for about 4 hours before bacteria convert dietary nitrates to nitrites 3 4 6
          • Test is less useful in infants because they empty their bladders more frequently
        • Sensitivity is poor (mean is 53%, with wide range); specificity is 90% to 100% 4 6
    • Urine microscopy 1
      • Pyuria (WBCs in urine) and bacteriuria (bacteria in urine) may be assessed by 2 methods 23
        • Standard urinalysis method: spun urine assessed visually
          • Pyuria defined as more than 5 WBCs per high-power field 4 6
            • Sensitivity averages 73% and specificity averages 81% (however, sensitivity and specificity range widely across reports) 4 6 23
          • Bacteriuria defined as presence of any bacteria on a gram-stained specimen 4 6
            • Sensitivity averages 81% and specificity averages 83% (however, sensitivity and specificity range widely across reports) 1
        • Enhanced urinalysis method: automatic hemacytometer or counting chamber on nonspun urine for WBC counts; microscopy for estimation of bacterial count
          • Sensitivity and specificity are about 10% better than with standard method (reports vary)
          • Superior in certain clinical situations, such as evaluation of very young infants 4 6 12
          • Pyuria defined as more than 10 WBCs/μL 4 6
            • Sensitivity is about 91%; specificity, about 96% (reports vary) 12
          • Bacteriuria is defined as any gram-negative rod in 10 oil immersion fields 4 6
    • Combined test performance
      • Test results positive for leukocyte esterase or nitrites have variable sensitivity and specificity (inferior to those of combined results) 4 6
      • Test results positive for leukocyte esterase and nitrites have 80% to 90% sensitivity and 60% to 98% specificity; negative predictive value approaches 100% if both are negative 3
      • Test results positive for leukocyte esterase, nitrites, or bacteriuria have 99.8% sensitivity and 70% specificity 4 6
      • Positive standard urinalysis (with bacteria and more than 5 WBCs per high-power field) has approximately 66% sensitivity and 99% specificity 3
      • Positive enhanced urinalysis (with bacteria and more than 10 WBC/μL) has approximately 85% sensitivity and 99.7% specificity 23
  • Urine culture
    • Obtain for children who have had catheterization for febrile illness if child is otherwise symptomatic or urinalysis is positive for 1 or more of the following:
      • Leukocyte esterase
      • Nitrites
      • Pyuria
      • Bacteriuria
    • Catheter or suprapubic specimen is required to establish definitive diagnosis of urinary tract infection in a non–toilet-trained child 4 6
    • Positive culture result depends on urine collection method 4 6
      • Cutoff definitions vary; they are operational and not absolute 4 6
        • Lower colony counts in a symptomatic patient may be significant 4 6
      • Urine catheterization technique 12
        • American guidelines definition: 50,000 or more CFU/mL of a single urinary pathogen 4 6
        • European guidelines definition: 1,000 to 50,000 CFU/mL of a single urinary pathogen 24
        • Other sources’ definition: 10,000 (10⁴) or more CFU/mL with a positive urinalysis 1
      • Suprapubic aspiration
        • 100 (10²) or more CFU/mL of a single urinary pathogen 1
        • Cutoff threshold also defined as any growth of a single urinary pathogen
      • Clean-catch method
        • Classical definition: 100,000 (10⁵) or more CFU/mL of a single urinary pathogen 1 24
        • European guidelines definition: 10⁴ or more CFU/mL in symptomatic patient and 10⁵ or more CFU/mL in asymptomatic patient 24
    • Contamination
      • Factors that raise suspicion of a contaminated culture specimen include the following:
        • Low colony counts relative to collection method
        • Growth of more than a single organism 18 24
        • Growth of a single nonuropathogenic organism, such as: 4 6
          • Lactobacillus species
          • Corynebacterium species
          • α-hemolytic streptococci
          • Micrococcus species
          • Coagulase-negative staphylococci
          • Candida species (in an otherwise healthy person)

Imaging

  • Ultrasonography 1
    • Reliably identifies a renal abscess, pyonephrosis with obstructive uropathy, urinary stone, or urinary obstruction in the acute setting
    • Abnormal anatomical findings (in the acute or follow-up setting) can include: abnormal kidney size, renal scarring, hydroureter, hydronephrosis, duplicated collecting system, ureterocele, or bladder diverticula
      • Directly identifies anatomical abnormalities and indirectly identifies functional abnormalities that increase risk for recurrent infection and subsequent renal scarring
    • Postvoid evaluation of bladder in toilet-trained children can be useful to assess for functional bladder abnormalities and retention syndrome
    • Limitations to renal ultrasonography 5
      • Not accurate in identifying all renal scarring from previous urinary tract infections and can miss some renal scarring
      • Unreliably identifies acute pyelonephritis without obstruction
      • Does not reliably identify signs of low-grade vesicoureteral reflux
    • Follow-up imaging
      • Youth of child is inversely proportional to risk of detecting an abnormality (on follow-up ancillary study) that will predispose the child to future urinary tract infections and potential complications 11
        • Structural abnormalities occur in 10% to 75% (median, about 30%) of children scanned after a first urinary tract infection 18
      • Controversial in the setting of first febrile infection; variability exists between recommendations for imaging in acute and follow-up settings, and is largely based on individual clinical scenario and clinical judgment 1
        • American Academy of Pediatrics recommends routine imaging after first febrile urinary tract infection in infants and children younger than 24 months 4 6
          • If screening ultrasonographic results are normal, no further studies are indicated after the first uncomplicated urinary tract infection
        • American College of Radiology suggests that there is no clear benefit for imaging of patients older than 2 months who respond well to treatment after first febrile urinary tract infection; this is true because: 13
          • Long-term complication rates after a febrile urinary tract infection are low, and
          • Benefit of treatment (ie, prophylactic antibiotics or surgery for reflux) is uncertain in most patients older than 2 months
        • Australasian guideline (2014) does not recommend routine ultrasonography after a first infection except in the following patients: 18
          • Patients who have not had imaging of kidney and urinary tract by second- or third-trimester antenatal ultrasonography
          • Patients with concurrent bacteremia
          • Infants younger than 3 months
          • Patients with urine culture finding of atypical organisms (eg, Staphylococcus aureusPseudomonas species)
          • Patients with lack of clinical response by sensitive organism within 48 hours
          • Patients with renal impairment or significant electrolyte derangement
          • Patients with abdominal mass or poor urinary stream
        • National Institute for Health and Care Excellence guidelines are detailed and have additional imaging recommendations 19
          • Follow-up ultrasonography is recommended in the following patients:
            • All children younger than 6 months should have ultrasonography within 6 weeks of the first urinary tract infection (when not required during acute phase of infection)
            • All children aged 6 months and older with recurrent infection
              • Infants and children aged 6 months or older with first-time urinary tract infection that responds to treatment do not require routine ultrasonography unless they have atypical infection
  • Voiding cystourethrography 3
    • Test of choice for diagnosis of vesicoureteral reflux in any age group
    • Test of choice to evaluate for vesicoureteral reflux in boys, because test allows clear demonstration of urethral pathology 13
  • Nuclear cystography
    • Alternate test of choice to evaluate for vesicoureteral reflux
    • Preferred by some experts to evaluate vesicoureteral reflux in girls and for follow-up of vesicoureteral reflux 13
    • Associated with a lower radiation exposure than voiding cystourethrography 13
  • Renal cortical scintigraphy with radiolabeled succimer (dimercaptosuccinic acid) as the radiotracer
    • Test of choice to assess for renal scarring and acute pyelonephritis 13
    • Indirectly evaluates for high-grade vesicoureteral reflux 13
      • Children with negative scan results have less than 1% probability of having high-grade vesicoureteral reflux 25
    • Radiation dose is much higher than with voiding cystourethrography (10-fold higher) and nuclear cystography (100-fold higher) 13
    • No longer recommended by American Academy of Pediatrics for patients aged 2 to 24 months as part of routine screening evaluation after a first febrile urinary tract infection 4 6

Procedures

Before any procedure to obtain urine in a non–toilet-trained child, have a sterile container readily available to catch midstream urine in the event that stimulating the child before the procedure spontaneously results in urine production 4 6

Transurethral bladder catheterization
General explanation
  • Yields reliable results and is better tolerated than suprapubic aspiration 14
  • Sterile technique is used to catheterize urethra to obtain urine specimen
  • Topical or intraurethral lidocaine can reduce discomfort 1
  • Bedside ultrasonographic estimation of bladder volume before catheterization improves likelihood of successful catheterization 1
Indication
  • Concern for urinary tract infection in non–toilet-trained child
Interpretation of results
  • Positive urine culture result is defined by uropathogen population more than 50,000 CFU/mL 4 6
  • Using this collection technique (as compared with suprapubic aspiration), sensitivity is 95% and specificity is 99% 4 6
Suprapubic aspiration
General explanation
  • Gold standard method of obtaining urine specimen for culture; better tolerated and has lower procedure failure rate than urethral catheterization, although the latter yields reliable results 1
  • Success rates for obtaining urine vary from 23% to 90% per attempt; rates improve with ultrasonographic guidance 3 4 6
  • Parents perceive procedure to be unacceptably invasive compared with urethral catheterization 4 6
  • Requires technical expertise and training
  • Use sterile technique 8
  • Insert 22-gauge needle 1 to 2 cm cephalad to pubic symphysis, midline, at an angle of 10° to 20° from vertical while aspirating until urine is retrieved from bladder
Indication 4 6
  • Inability to obtain urine by catheterization technique, such as with:
    • Boys with moderate to severe phimosis
    • Girls with tight labial adhesions
Interpretation of results
  • Positive urine culture result is defined by uropathogen population more than 50,000 CFU/mL 4 6

Differential Diagnosis

Most common

  • Asymptomatic bacteriuria in a febrile child 46
    • Small number of healthy, asymptomatic children have bacteriuria
      • Defined as a urine culture with more than 50,000 CFU of a single uropathogen and absence of pyuria
    • Often found in otherwise healthy school-aged or adolescent girls; may be present in infants
    • There is no way to reliably differentiate between preexisting asymptomatic bacteriuria and urinary tract infection in a febrile child with signs of urinary tract infection based on a positive culture result in the acute setting 1
      • Diagnosis usually requires time; asymptomatic bacteriuria persists outside febrile illness time frame 1
    • Differentiate by absence of pyuria (per WBC count or leukocyte esterase test) on initial urinalysis and persistence of a positive culture result despite absence of symptoms
  • Sexually transmitted diseases
    • Urethral inflammation can cause dysuria, hematuria, and urethral discharge
    • Boys present with urethritis
    • Can present concomitantly with urinary tract infection 3
      • However, 29% of sexually active adolescent girls with urinary symptoms have a sexually transmitted disease only 3
    • Pelvic inflammatory disease
    • Differentiate based on history, physical examination, urine culture, and specific testing for sexually transmitted diseases (eg, chlamydia, gonorrhea, trichomoniasis)
  • Hemorrhagic viral cystitis
    • Symptoms include:
      • Dysuria
      • Urinary urgency and frequency
      • Hematuria (usually at beginning of urine stream and tapering off by end)
      • Suprapubic pain and/or tenderness
    • Usually associated with adenoviral or other upper respiratory infection
    • Screening urinalysis finds absence of signs of bacteriuria; differentiate based on urine culture
  • Nephrolithiasis
    • Presents with the following:
      • Flank pain or renal colic
      • Urinary symptoms
      • Gross or microscopic hematuria
      • Absence of fever
    • Many children with urinary stones have positive family history
    • Concomitant infection with urinary stone is a consideration when patient is presenting with pain disproportionate to or uncharacteristic of uncomplicated urinary tract infection
    • Differentiate based on history and urine culture
  • Vulvovaginitis (caused by chemical, irritant, bacteria, or yeast)
    • Usually presents with dysuria and absence of urinary frequency
    • Physical examination may show vaginal discharge, inflammation around urinary meatus, or skin breakdown in perineum
    • Bacterial vaginitis in a child may be the result of a vaginal foreign body
    • May be caused by trichomoniasis in adolescents
    • Differentiate based on physical examination and urine culture
  • Sexual abuse or periurethral trauma
    • Can present with dysuria, hematuria, or urinary retention
    • Urinary frequency is uncommon
    • Signs of perineal or perianal trauma may be present on examination
    • Differentiate based on history, physical examination, information obtained from social services consultation, and urine culture

Treatment

Goals

  • Treat symptoms of fever, dysuria, and pain
  • Eliminate infection and prevent severe systemic illness: start empiric treatment with antibiotics and modify them based on culture and sensitivity test
  • Prevent or reduce possible long-term complications with adequate follow-up

Disposition

Admission criteria 1

Age younger than 2 to 3 months

Severe illness

Dehydration

Inability to tolerate oral fluids or medications

High risk for nonadherent follow-up

Immunocompromised status 3

Underlying urologic conditions 3

Renal obstruction

No response to outpatient therapy

Criteria for ICU admission
  • Hypotension or septic shock

Recommendations for specialist referral

  • Refer to a pediatric urologist any patient with complex infection, high risk of recurrent infection, or evidence of renal damage, including the following: 5 8
    • Pyonephrosis, renal or perirenal abscess, and emphysematous pyelonephritis
    • Imaging abnormalities (eg, hydronephrosis, obstruction, renal scarring)
    • Vesicoureteral reflux
    • Recurrent urinary tract infections
    • High risk for serious illness
  • Consider pediatric urologist referral for the following:
    • Infants younger than 3 months
    • Children with pyelonephritis or febrile urinary tract infection
  • Refer patients with the following to pediatric nephrologist:
    • Renal scarring
    • Abnormal renal function that persists despite urinary tract infection treatment
  • Obtain infectious disease consultation for any patient found to have urinary tract infection with uncommon organism

Treatment Options

Treatment overview

  • Start empiric treatment based on clinical suspicion given a history and physical examination suggestive of urinary tract infection and urinary findings suggestive of presumptive diagnosis on an appropriately collected urine specimen 18
    • Positive urinary dipstick result (ie, leukocyte esterase or nitrite), and/or
    • Positive microscopy (ie, bacteriuria or pyuria)
  • Oral antibiotics are as efficacious as parenteral antibiotics for treatment of urinary tract infections in otherwise healthy children older than 2 months 4 5 6
    • Parenteral therapy is reserved for children who appear very ill, 4 6 who are unable to tolerate oral medications, 4 6 or who are younger than 2 months 24 19
    • Consider parenteral therapy in children with complicated infection in consultation with specialist (eg, urologist, nephrologist)
    • Continue parenteral antibiotic therapy until child is afebrile and tolerating oral intake 24
  • Most febrile but otherwise healthy infants and children can be managed as outpatients, according to American Academy of Pediatrics guidelines 1
  • Before start of empiric antibiotics, obtain a catheter or suprapubic urine specimen for culture in an any febrile child aged 24 months or younger (for confirmatory diagnosis) 4 6
    • If possible, obtain urine before emergent empiric antibiotic administration in a febrile child to evaluate for urinary tract infection (if child is at risk)
    • Never start empiric antibiotics to treat a presumptive urinary tract infection based on bag specimen result alone; always obtain a catheter or suprapubic specimen for screening urinalysis and culture before starting antimicrobial therapy if bag specimen is concerning for urinary tract infection 4 6
  • Children with initial diagnosis of uncomplicated urinary tract infection should have clinical response to antibiotics within 24 to 48 hours (ie, improved symptoms, defervescence) 1 4 6
    • Lack of response within 48 hours indicates a complicated course (eg, renal abscess, obstruction presence, alternative diagnosis) or a pathogen not covered by empiric antibiotics 1 4 6
    • Consider further work-up, ultrasonography, and broadening of antibiotic coverage 1
  • Additional guidelines for the treatment of pediatric urinary tract infection are available
    • National Institute for Health and Care Excellence guidelines (updated 2018) 19
    • European Society for Paediatric Urology and European Association of Urology joint guidelines (updated annually) 9
    • Australian Kidney 2014 guidelines 18 20
    • Canadian 2014 guidelines (reaffirmed in 2017) 21
    • International Children’s Continence Society 2012 recommendations 22
    • American Academy of Pediatrics 2011 guidelines (reaffirmed in 2016) 4 6

Drug therapy

  • Base initial empiric antibiotic choice on local community sensitivity patterns, then adjust based on patient’s own culture and sensitivity results 3 4 6 10
    • Gram stain may help with initial choice of antibiotics; many recommended empiric antibiotics (eg, first- and second-generation cephalosporins) do not cover Enterococcus species (gram-positive uropathogen) or Staphylococcus saprophyticus 10
    • Consider child’s previous antimicrobial exposure and alter empiric antibiotic choice accordingly
    • Consider known underlying medical problems (eg, immunodeficiency, diabetes), vesicoureteral reflux, or anatomic abnormalities that may alter treatment approach
    • Earlier history of urinary tract infection decreases threshold for treatment with empiric antibiotics; review previous culture and susceptibility results
    • Resistance of Escherichia coli to amoxicillin, amoxicillin-clavulanate, sulfamethoxazole-trimethoprim, 8 and first-generation cephalosporins is increasing 10
  • Antibiotic selection
    • In general, children managed as outpatients should be given a third-generation cephalosporin 4 6
      • Some clinicians administer an initial parenteral dose of ceftriaxone to infants younger than 6 months owing to increased risk of bacteremia and sepsis in this age group, although this does not have proven better outcomes 1
      • Owing to increasing resistance to third-generation cephalosporins, overconsumption in low-risk settings should be avoided 26
      • National Institute for Health and Care Excellence guidelines recommend trimethoprim (in those at low risk for resistance) or nitrofurantoin as first line in children aged 3 months or older; cephalexin or amoxicillin is an alternative, if sensitive organism is cultured 27
    • In general, use a third-generation cephalosporin or an aminoglycoside for children requiring admission and parenteral antibiotics 4 6
      • Treat infants younger than 2 to 3 months with combination therapy (ampicillin-gentamicin or ampicillin-cefotaxime) 11
        • National Institute for Health and Care Excellence guidelines recommend a third-generation cephalosporin (for example cefotaxime or ceftriaxone) plus an antibiotic active against Listeria (for example, ampicillin or amoxicillin) 28
      • National Institute for Health and Care Excellence guidelines recommend amoxicillin-clavulanate (if pathogen is known to be susceptible), cefuroxime, ceftriaxone, gentamicin, or amikacin for children older than 3 months 29
  • Duration of antibiotic therapy
    • 7 to 14 days is standard of care; use longer course of antibiotics in the following populations:
      • Children with febrile or complicated urinary tract infection 4 6
      • Children younger than 2 years 4 6 8
      • Children with recurrent infections 10
      • Children with pyelonephritis 10
      • All adolescent males 10
    • Shorter courses of antibiotics (ie, 2-4 days) are likely as effective as longer courses for uncomplicated cystitis 18 30
      • European guidelines suggest at least 3 days 24
  • Medications
    • Antibiotics
      • Cephalosporins (do not cover Enterococcus species)
        • Ceftriaxone 4 6
          • Avoid in neonates with hyperbilirubinemia
          • Ceftriaxone Sodium Solution for injection; Premature† and Term Neonates: 50 to 75 mg/kg/day IV/IM divided every 12 to 24 hours.
            • Off-label use in premature neonates
          • Ceftriaxone Sodium Solution for injection; Infants, Children, and Adolescents: 50 to 75 mg/kg/day divided every 12 to 24 hours (Max: 2 g/day) for 7 to 14 days.
        • Cefotaxime 4 6
          • Cefotaxime Sodium Solution for injection; Neonates 32 weeks gestation and older and 0 to 7 days: 50 mg/kg/dose IV/IM every 12 hours.
          • Cefotaxime Sodium Solution for injection; Neonates 32 weeks gestation and older and 8 days and older: 50 mg/kg/dose IV/IM every 8 hours.
          • Cefotaxime Sodium Solution for injection; Infants, Children, and Adolescents weighing less than 50 kg: 150 to 180 mg/kg/day IV/IM divided every 6 to 8 hours (Max: 2 g/dose).
          • Cefotaxime Sodium Solution for injection; Children and Adolescents weighing 50 kg or more: 1 g IV/IM every 12 hours for uncomplicated infections; 1 to 2 g IV/IM every 8 hours for moderate to severe infections; 2 g IV every 6 to 8 hours for severe infections, and 2 g IV every 4 hours for life-threatening infections. Max: 12 g/day.
        • Cefixime 4 6
          • Cefixime Oral suspension; Infants 2 to 5 months†: 8 mg/kg/dose PO once daily for 7 to 14 days.
            • Off-label use in this age group
          • Cefixime Oral suspension; Infants and Children 6 months to 2 years: 8 mg/kg/day PO divided every 12 to 24 hours for 7 to 14 days.
          • Cefixime Oral suspension; Children 3 years and older weighing 45 kg or less: 8 mg/kg/day PO divided every 12 to 24 hours.
          • Cefixime Oral suspension; Children weighing more than 45 kg and Adolescents: 400 mg/day PO divided every 12 to 24 hours.
        • Cefdinir 31
          • Cefdinir Oral suspension; Infants, Children, and Adolescents: 7 mg/kg/dose PO every 12 hours or 14 mg/kg/dose PO every 24 hours. Treat febrile infants and young children 2 to 24 months of age for 7 to 14 days; shorter courses (2 to 4 days) may be used in older children with uncomplicated cystitis.
      • Broad-spectrum aminopenicillins (covers Enterococcus species)
        • Ampicillin 32
          • Ampicillin Sodium Solution for injection; Neonates 34 weeks gestation and younger and 0 to 7 days†: 50 mg/kg/dose IV/IM every 12 hours.
          • Ampicillin Sodium Solution for injection; Neonates 34 weeks gestation and younger and older than 7 days†: 75 mg/kg/dose IV/IM every 12 hours.
          • Ampicillin Sodium Solution for injection; Neonates older than 34 weeks gestation†: 50 mg/kg/dose IV/IM every 8 hours.
          • Ampicillin Sodium Solution for injection; Infants, Children, and Adolescents: 50 to 200 mg/kg/day IV/IM divided every 6 hours (Max: 8 g/day).
        • Piperacillin 4 6
          • Piperacillin Sodium Solution for injection; Children >= 12 years and Adolescents: Not recommended in most guidelines. 300 to 400 mg/kg/day (Max: 12 to 24 g/day) IV/IM in 4 to 6 divided doses for severe infections; 200 mg/kg/day (Max: 6 to 16 g/day) IV/IM in 3 to 4 divided doses for mild/moderate infections. Manufacturer recommends treat for 7 to 10 days. IV suggested for serious infections.
        • Amoxicillin-clavulanate combination 4 6
          • Amoxicillin Trihydrate, Clavulanate Potassium Oral suspension; Neonates and Infants 2 months and younger: 30 mg/kg/day amoxicillin component PO divided every 12 hours.
          • Amoxicillin Trihydrate, Clavulanate Potassium Oral suspension; Infants, Children, and Adolescents 3 months to 17 years weighing less than 40 kg (every 12 hour regimens): 25 mg/kg/day amoxicillin component PO divided every 12 hours for mild/moderate infections and 45 mg/kg/day amoxicillin component PO divided every 12 hours for severe infections.
          • Amoxicillin Trihydrate, Clavulanate Potassium Oral suspension; Children and Adolescents weighing 40 kg or more (every 12 hour regimens): 500 mg amoxicillin with 125 mg clavulanic acid PO every 12 hours for mild/moderate infections and 875 mg amoxicillin with 125 mg clavulanic acid PO every 12 hours for severe infections.
      • Aminoglycosides
        • Potentially nephrotoxic; use with care in patients with impaired renal function
        • Gentamicin 4 6
          • Conventional dosing
            • Gentamicin Sulfate Solution for injection; Neonates 0 to 7 days weighing less than 1.2 kg: 2.5 mg/kg/dose IV/IM every 18 to 24 hours. FDA-approved dosage = 2.5 mg/kg/dose IV/IM every 12 hours.
            • Gentamicin Sulfate Solution for injection; Neonates 0 to 7 days weighing 1.2 to 2 kg: 2.5 mg/kg/dose IV/IM every 12 to 18 hours.
            • Gentamicin Sulfate Solution for injection; Neonates 0 to 7 days weighing more than 2 kg: 2.5 mg/kg/dose IV/IM every 12 hours; extend interval to 18 to 24 hours for neonates on ECMO. Individualize subsequent dosing based on serum concentrations. Dosage adjustment needed after decannulation.
            • Gentamicin Sulfate Solution for injection; Neonates 8 to 29 days weighing less than 1.2 kg: 2.5 mg/kg/dose IV/IM every 18 to 24 hours. FDA-approved dosage = 2.5 mg/kg/dose IV/IM every 8 hours.
            • Gentamicin Sulfate Solution for injection; Neonates 8 to 29 days weighing 1.2 to 2 kg: 2.5 mg/kg/dose IV/IM every 8 to 12 hours.
            • Gentamicin Sulfate Solution for injection; Neonates 8 to 29 days weighing more than 2 kg: 2.5 mg/kg/dose IV/IM every 8 hours; extend interval to 18 to 24 hours for neonates on ECMO. Individualize subsequent dosing based on serum concentrations. Dosage adjustment needed after decannulation.
            • Gentamicin Sulfate Solution for injection; Infants: 2.5 mg/kg/dose IV/IM every 8 hours; treat for 7 to 14 days for initial UTI in febrile patients 2 to 24 months of age.
            • Gentamicin Sulfate Solution for injection; Children and Adolescents: 2 to 2.5 mg/kg/dose IV/IM every 8 hours; treat for 7 to 14 days for initial UTI in febrile patients 2 to 24 months of age.
          • Extended-interval dosing
            • Single daily dosing may be preferred owing to improved safety profile and similar efficacy compared with more frequent dosing regimens 24
            • Gentamicin Sulfate Solution for injection; Neonates younger than 30 weeks gestation and 0 to 14 days: 5 mg/kg/dose IV/IM every 48 hours.
            • Gentamicin Sulfate Solution for injection; Neonates younger than 30 weeks gestation and 15 days and older: 5 mg/kg/dose IV/IM every 36 hours.
            • Gentamicin Sulfate Solution for injection; Neonates 30 to 34 weeks gestation and 0 to 14 days: 5 mg/kg/dose IV/IM every 36 hours.
            • Gentamicin Sulfate Solution for injection; Neonates 30 to 34 weeks gestation and 15 days and older: 5 mg/kg/dose IV/IM every 24 hours.
            • Gentamicin Sulfate Solution for injection; Neonates 35 weeks gestation and older and 0 to 7 days: 4 mg/kg/dose IV/IM every 24 hours.
            • Gentamicin Sulfate Solution for injection; Neonates 35 weeks gestation and older and 8 days and older: 5 mg/kg/dose IV/IM every 24 hours.
            • Gentamicin Sulfate Solution for injection; Infants, Children, and Adolescents: 5 to 7.5 mg/kg/dose IV/IM every 24 hours; treat for 7 to 14 days for initial UTI in febrile patients 2 to 24 months of age.
      • Nitrofurantoin 8
        • Not indicated for febrile urinary tract infection; 1 does not achieve therapeutic serum or renal concentrations to effectively treat pyelonephritis 8
        • Nitrofurantoin Oral suspension; Infants, Children, and Adolescents weighing less than 42 kg: 5 to 7 mg/kg/day PO in 4 divided doses. Give for 7 days or for at least 3 days after urine is sterile.
        • Nitrofurantoin Oral suspension; Children and Adolescents weighing 42 kg or more: 50 to 100 mg PO every 6 hours. Give for 7 days or for at least 3 days after urine is sterile.
      • Sulfonamides
        • Sulfamethoxazole-trimethoprim combination 4 6
          • Useful for Staphylococcus saprophyticus infection 10
          • Sulfamethoxazole, Trimethoprim Oral suspension; Infants and Children 2 months to 2 years: 6 to 12 mg/kg/day (trimethoprim component) PO divided every 12 hours for 7 to 14 days.
          • Sulfamethoxazole, Trimethoprim Oral suspension; Children and Adolescents 3 to 17 years: 8 mg/kg/day (trimethoprim component) PO every 12 hours (Max: 320 mg trimethoprim/1,600 mg sulfamethoxazole/day) for 10 days.
        • Sulfisoxazole 4 6
          • Sulfisoxazole Acetyl Oral suspension; Infants > 2 months and Children: 75 mg/kg or 2 g/m2 PO then 120—150 mg/kg/day, or 4 g/m2/day, in 4—6 equally divided doses. Max 6 g/day.
      • Fluoroquinolones
        • Ciprofloxacin 8
          • Approved for second line treatment of complicated or multidrug-resistant infections 10
          • Ideally reserved for patients older than 18 years owing to potential risk of damaging cartilage
            • Ciprofloxacin Hydrochloride Oral tablet; Children and Adolescents: 10 to 20 mg/kg/dose PO every 12 hours (Max: 750 mg/dose) for 7 to 14 days; FDA-approved labeling recommends a duration up to 21 days.
    • Analgesics
      • Phenazopyridine 33
        • Avoid in patients with glucose-6-phosphate dehydrogenase deficiency or moderate to severe renal impairment
        • Appropriate for children aged 6 years or older
          • Phenazopyridine Hydrochloride Oral tablet; Children 6 to 11 years†: Use not established; off-label use has been described. Use only under the prescription of a health care professional; do not self-treat. Dose used: 4 mg/kg/dose PO 3 times daily with or after meals for up to 2 days.
            • Off-label use in these age groups
          • Phenazopyridine Hydrochloride Oral tablet; Children and Adolescents 12 to 17 years: 190 to 200 mg PO 3 times daily with or after meals. Non-prescription use or use with an antibacterial agent for urinary tract infection should not exceed 2 days.

Nondrug and supportive care

  • Fever and pain
    • Ibuprofen
    • Acetaminophen
  • Hydration
    • Encourage oral fluid intake
    • Provide IV hydration to any child with clinical signs of dehydration or poor urine output
  • Evaluate all toilet-trained children for possibility of bowel and bladder dysfunction (with history and physical examination) 5 10
    • Address bladder and bowel dysfunction if present 24
      • Urologic anticipatory guidance mantra is that “a happy bladder is an empty bladder; an even happier bladder is an empty rectum” 5
      • Bladder training 5
        • Timed voiding (every 2-3 hours) to avoid bladder distention and stasis
        • Double voiding: attempt to urinate immediately after initial void
        • Avoidance of caffeine, carbonated beverages, citrus, chocolate, and food colorants
        • Biofeedback for pelvic floor muscle relaxation
        • Anticholinergic medications 5
        • α-blockers 5
      • Training for constipation 5
        • Daily sit-downs: 10 minutes sitting on toilet after breakfast and dinner; follow behavior with positive reinforcement (eg, reward with star on a chart)
        • Increased dietary fiber
        • Laxatives
  • Short-term follow-up for child managed as outpatient
    • Arrange in-office and phone follow-up
      • Provide urine sensitivity results and modify treatment accordingly
      • Encourage return visit if child continues to have fever after 48 hours of treatment or if symptoms worsen
  • Long-term follow-up for child managed as outpatient
    • Uncomplicated urinary tract infection: ensure appropriate outpatient imaging is scheduled
    • Complicated urinary tract infection: if child meets criteria for urologist referral, ensure adequate follow-up by urologist
  • Anticipatory guidance
    • Parents should seek medical attention within 48 hours in case of future febrile illness or urinary symptoms to ensure that recurrent infections are detected and treated promptly (especially in children younger than 2 years) 4 6

Monitoring

  • Monitor for clinical improvement within days after diagnosis
    • Expect normalization of temperature within 24 to 48 hours with successful treatment 24
    • Expect sterile urine within 24 hours and disappearance of leukocyturia by day 3 or 4 with successful treatment 24
    • Consider antibiotic-resistant uropathogen, presence of congenital uropathy, or acute urinary obstruction if condition does not respond to standard care 24
  • Short-term follow-up for child managed as outpatient
    • Arrange in-office and phone follow-up
      • Provide urine sensitivity results and modify treatment accordingly
      • Encourage return visit if child continues to have fever after 48 hours of treatment or if symptoms worsen
  • Long-term follow-up for child managed as outpatient
    • Uncomplicated urinary tract infection: ensure appropriate outpatient imaging is scheduled
    • Complicated urinary tract infection: if child meets criteria for urologist referral, ensure adequate follow-up by urologist
  • Long-term monitoring for specific situations
    • Patients with vesicoureteral reflux require yearly (or more frequent) follow-up voiding cystourethrogram and renal ultrasonography 5 10
    • Patients with renal scarring require yearly (or more frequent) measurement of blood pressure and proteinuria (urinalysis) 10
    • Patients with bilateral renal scarring require yearly measurement of blood pressure, proteinuria (urinalysis), and creatinine level 10
    • Patients with a history of urinary tract infection 10
      • Monitor for bowel and bladder dysfunction through history and physical examination 10
      • Untreated dysfunction may contribute to recurrent infections and lead to renal complications 10 24
  • Anticipatory guidance
    • Parents should seek medical attention within 48 hours in case of future febrile illness or urinary symptoms to ensure that recurrent infections are detected and treated promptly (especially in children younger than 2 years)

Complications and Prognosis

Complications

  • Must be identified and treated promptly to minimize risk of renal abscess, sepsis, and renal parenchymal damage
  • Short-term 1
    • Sepsis
      • 6% to 36% of neonatal infections are complicated by sepsis (reports vary) 13
    • Renal abscess or perinephric abscess
    • Pyonephrosis with obstructive uropathy
    • Advent of chronic pyelonephritis
      • Emphysematous pyelonephritis is rare in children
  • Recurrent infection
    • Up to 30% of infants and children experience recurrent infections 24
    • Most recurrent infections occur within 3 to 6 months after the first episode 13
    • Children with recurrent infection are at risk for renal scarring
    • Risk factors for recurrent infection in young children include:
      • White race 34
      • Age of 3 to 5 years 34
      • Vesicoureteral reflux 35
        • Higher grades of vesicoureteral reflux (ie, grades 4-5) may be associated with further increased risk 34
      • Presence of baseline bowel and bladder dysfunction 35
      • Presence of renal scarring at baseline 35
    • Antimicrobial prophylaxis is controversial and not standardized 34
      • Long-term antibiotics may reduce risk of recurrent urinary tract infection in children who have had 1 or more previous infections, but the benefit appears small 36
      • Use of long-term antibiotic prophylaxis is associated with increased risk of antimicrobial resistance among children with recurrent infections 36
      • Insufficient and conflicting evidence along with inconsistent guideline recommendations confound the decision 24
        • Individual factors (eg, age, sex, circumcision status, presence and severity of vesicoureteral reflux) must be weighed against potential harms associated with daily antibiotic use and possibility of antimicrobial resistance
        • Risk factors for recurrence in infants with vesicoureteral reflux include: 24 37
          • Earlier occurrence of first infection
          • Higher grades of reflux
          • Bilateral reflux
          • First infection caused by an organism that is not Escherichia coli
      • Overall decision is individualized based on urologist recommendations; prophylactic antibiotics may be recommended for infants and children at highest risk for recurrence 18
        • Evidence exists for use to prevent renal scarring in infant girls with dilating reflux grade III and IV 24 38
        • Other experts support antibiotic prophylaxis in all children with vesicoureteral reflux regardless of reflux grade 39
        • Some guidelines suggest consideration for antimicrobial prophylaxis for recurrent infections regardless of presence of reflux 40
      • Trimethoprim/sulfamethoxazole if first line antibiotic of choice in most infants and children requiring prophylaxis; 18 24 trimethoprim, nitrofurantoin, cephalexin, or amoxicillin is recommended by the National Institute of Health and Care Excellence 40
        • Optimum duration of therapy is not available; most children receive at least 6 months to 2 years of prophylaxis 18
      • Probiotics may have a role in reducing risk of recurrent urinary tract infection in children with a normal urinary tract; however, results have been conflicting 41 42
      • Data to support other treatment for children with recurrent infection and vesicoureteral reflux are not convincing 18 43
        • Invasive procedures aimed at diminishing backflow of urine from bladder toward kidneys are reserved for patients with recurring symptomatic infections unimproved by other less invasive preventive measures and include:
          • Surgery to reimplant the ureter
          • Injection of agents to increase the stiffness of the ureter
  • Long-term
    • Complications after uncomplicated cystitis are rare 13
    • Complications after pyelonephritis
      • Renal parenchymal scarring occurs in about 15% of children overall after the first episode of infection 13
        • Future hypertension occurs in 10% to 30% of children, or possibly more, with renal parenchymal scarring 5
        • Other long-term consequences of renal scarring are not well described
        • Risk of renal scarring in children younger than 1 year is up to 43% after first infection 11
          • Future development of renal scarring is predicted by any 1 of the following: 44
            • Initial fever (higher than 39˚C)
            • Causative organism other than Escherichia coli
            • Abnormal ultrasonographic finding
            • Polymorphonuclear cell count of 60% or higher
            • C-reactive protein level of 40 mg/L or higher
            • Vesicoureteral reflux (grade 3 or higher)
      • Impaired renal function
      • Proteinuria
      • Chronic renal insufficiency requiring transplant is extremely rare
        • Child with normal kidneys is not at risk for developing end-stage renal disease 5
        • End-stage renal disease caused by recurrent childhood urinary tract infections occurs in 0.3% of patients 5
      • Chronic pyelonephritis

Prognosis

  • Most children have no long-term sequelae 45 46

Screening and Prevention

Screening

At-risk populations

  • Patients scheduled for invasive urologic procedures must undergo urinalysis to exclude urinary tract infection

Screening tests

  • Urinalysis (dipstick or microscopic) 4 6

Prevention

  • American Academy of Pediatrics encourages circumcision, but ultimately the decision remains with the parents 10
  • Encourage breast feeding, which is preventive 47
  • Avoid and treat voiding dysfunction 47
    • Encourage healthy bladder habits such as fully emptying bladder and not withholding urine
    • Encourage bowel movements and treat constipation
  • Avoid unnecessary antibiotic use 47
    • Disturbances in normal periurethral flora fosters potential uropathogen colonization
  • Adolescents
    • Encourage condom use if sexually active; discuss risk of sexually transmitted disease due to unprotected intercourse 15
  • Other harmless, yet unproven, recommended preventive measures that may decrease risk include:
    • Adequate fluid intake 18
    • Avoiding bubble baths 18
    • Improving cleaning methods after bowel movements 18
    • Frequent diaper changes to avoid prolonged perineal exposure to urine and feces

Sources

Bhat RG et al: Pediatric urinary tract infections. Emerg Med Clin North Am. 29(3):637-53, 2011

Cross Reference

You cannot copy content of this page