1. UTI and urinary tract anomalies
DR Badi AlEnazi
Consultant pediatric endocrinology and diabetologist
MBBS,SBP,ABP,SFPE

2. Introduction
Urinary tract infection (UTI) is one of the most common pediatric infections. It distresses the child, concerns the parents, and may cause permanent kidney damage. Prompt diagnosis and effective treatment of a febrile UTI may prevent acute discomfort and, in patients with recurrent infections, kidney damage.

3. Epidemiology
The incidence of UTIs varies based on age, sex, and gender.
It was found that the overall prevalence of UTI in infants presenting with fever was 7.0%.
the rates in girls were as follows:
0-3 months - 7.5%
3-6 months - 5.7%
6-12 months - 8.3%
>12 months - 2.1%
In febrile boys less than 3 months of age:
2.4% of circumcised boys .
20.1% of uncircumcised boys .

4. The 2 broad clinical categories of UTI are:
pyelonephritis (upper UTI)
cystitis (lower UTI).

5. Pathophysiology
Typically, UTIs develop when uropathogens that have colonized the periurethral area ascend to the bladder via the urethra. From the bladder, pathogens can spread up the urinary tract to the kidneys (pyelonephritis) and possibly to the bloodstream (bacteremia).

6. Urine in the proximal urethra and urinary bladder is normally sterile
Urine in the proximal urethra and urinary bladder is normally sterile. Entry of bacteria into the urinary bladder can result from:
turbulent flow during normal voiding
voiding dysfunction
catheterization.
More rarely, the urinary tract may be colonized during systemic bacteremia (in infancy).
direct spread via the fecal-perineal-urethral route.

7. Etiology
Bacterial infections are the most common cause of UTI, with E coli being the most frequent pathogen, causing % of UTIs. Other bacterial sources of UTI include the following:
Klebsiella species
Proteus species
Enterococcus species
Streptococcus group B, especially among neonates
Pseudomonas aeruginosa
Fungi (Candida species) may also cause UTIs
Adenovirus is a rare cause of UTI and may cause hemorrhagic cystitis.

9. Risk factors
Susceptibility to UTI may be increased by any of the following factors:
Anatomic anomaly
Bowel and bladder dysfunction
Constipation

14. Circumcision and UTI
For male infants, neonatal circumcision substantially decreases the risk of UTI. It was found that during the first year of life, the rate of UTI was 2.15% in uncircumcised boys, versus 0.22% in circumcised boys. Risk is particularly high during the first 3 months of life.

15. Diagnosis
The American Academy of Pediatrics (AAP) criteria for the diagnosis of UTI in children months:
are the presence of pyuria and/or bacteriuria on urinalysis and of at least 50,000 colony-forming units (CFU) per mL of a uropathogen from the quantitative culture of a properly collected urine specimen.

16. Urine specimen collection
A midstream, clean-catch specimen may be obtained from children who have urinary control.
In the infant or child unable to void on request, the specimen for culture should be obtained by suprapubic aspiration or urethral catheterization.

18. Suprapubic aspiration is also the method of choice for obtaining urine from uncircumcised boys,from girls with tight labial adhesions, and from children of either sex with clinically significant periurethral irritation.

20. Culture of a urine specimen from a sterile bag attached to the perineal area has a false-positive rate so high that this method of urine collection is not suitable for diagnosing UTI.
However, a culture of a urine specimen from a sterile bag that shows no growth is strong evidence that UTI is absent.

21. Urinalysis
Urinalysis alone is not sufficient for diagnosing UTI. Children with unexplained fever or voiding symptoms may have positive urinary cultures even when abnormal findings are not evident on complete urinalysis.

22. Evaluation of renal function
Renal function can be measured by serum creatinine and blood urea nitrogen (BUN) levels; both may be elevated in severe disease. Electrolyte abnormalities may be present.

23. Imaging studies Ultrasonography
Urinary ultrasonography is useful in:
excluding obstructive uropathy
identifying a solitary or ectopic kidney
moderate renal damage caused by pyelonephritis.

24. indications for ultrasonography of the urinary tract after a febrile UTI in pediatric patients are as follows:
Delayed or unsatisfactory response to treatment of a first febrile UTI
An abdominal mass or abnormal voiding (dribbling of urine)
Recurrence of febrile UTI after a satisfactory response to treatment

25. Performance of voiding cystourethrography (VCUG) after a first febrile UTI may be indicated if:
renal and bladder ultrasonography reveal hydronephrosis, scarring, obstructive uropathy, or masses
complex medical conditions are associated with the UTI.

26. VCUG is also recommended after a second episode of febrile UTI
VCUG is also recommended after a second episode of febrile UTI. There is some concern, however, that without VCUG after the first documented febrile UTI, some cases of significant reflux disease will be missed

29. symptoms

31. Physical Examination Costovertebral angle tenderness
Abdominal tenderness to palpation
Suprapubic tenderness to palpation
Palpable bladder
Dribbling, poor stream, or straining to void
Examine the external genitalia for signs of irritation, pinworms, vaginitis, trauma

32. Treatment

33. Criteria of Hospital Admission
Usual indications for hospitalization and/or parenteral therapy include:
Age <2 months
Clinical urosepsis (eg, toxic appearance, hypotension, poor capillary refill)
Immunocompromised patient
Vomiting or inability to tolerate oral medication
Lack of adequate outpatient follow-up (eg, no telephone, live far from hospital, etc)
Failure to respond to outpatient therapy

34. Empiric therapy
Early and aggressive antibiotic therapy (eg, within 72 hours of presentation) is necessary to prevent renal damage.
Delayed therapy has been associated with increased severity of infection and greater likelihood of renal damage .

35. We suggest that empiric antimicrobial therapy be initiated immediately after appropriate urine collection in children with suspected UTI and a positive urinalysis. This is particularly true for children who are at increased risk for renal scarring if UTI is not promptly treated, including children who present with:
Fever (especially >39°C [102.2°F] or >48 hours)
Ill appearance
Costovertebral angle tenderness
Known immune deficiency
Known urologic abnormality

36. parenteral antibiotic therapy
The diagnosis in infant with a febrile UTI is usually based on fever and on positive results from a urine specimen obtained by catheterization. Infants with such findings are usually hospitalized and receive parenteral antibiotic therapy
Comment
Dosage and Route
Drug
Do not use in infants < 6 wk of age; parenteral antibiotic with long half-life; may displace bilirubin from albumin
50-75 mg/kg/day IV/IM as a single dose or divided q12h
Ceftriaxone
Safe to use in infants < 6 wk of age; used with ampicillin in infants aged 2-8 wk
150 mg/kg/day IV/IM divided q6-8h
Cefotaxime
Note: IM = intramuscular; IV = intravenous; q = every.

37. Comment
Dosage and Route
Drug
Used with gentamicin in neonates < 2 wk of age; for enterococci and patients allergic to cephalosporins
100 mg/kg/day IV/IM divided q8h
Ampicillin
Monitor blood levels and kidney function if therapy extends >48 h
Term neonates < 7 days: mg/kg/dose IV q24h Infants and children < 5 years: 2.5 mg/kg/dose IV q8h or single daily dosing with normal renal function of mg/kg/dose IV q24h Children ≥5 y: mg/kg/dose IV q8h or single daily dosing with normal renal function of mg/kg/dose IV q24h 
Gentamicin
Note: IM = intramuscular; IV = intravenous; q = every.

38. Antibiotic Agents for the Oral Treatment of Urinary Tract Infection
Daily Dosage
Protocol
30-60 mg/kg SMZ, 6-12 mg/kg TMP divided q12h
Sulfamethoxazole and trimethoprim (SMZ-TMP)
20-40 mg/kg divided q8h
Amoxicillin and clavulanic acid
mg/kg divided q6h
Cephalexin
8 mg/kg q24h
Cefixime
10 mg/kg divided q12h
Cefpodoxime
5-7 mg/kg divided q6h
Nitrofurantoin*
*Nitrofurantoin may be used to treat cystitis. It is not suitable for the treatment of pyelonephritis, because of its limited tissue penetration.

39. The AAP guidelines for the followup of these patients can be summarized as follows:
After 7 days of antimicrobial therapy, close clinical follow-up monitoring is required to help ensure that recurrent infections can be promptly diagnosed and treated
Ultrasonograms of the kidneys and bladder should be obtained in order to detect anatomic abnormalities
The routine use of VCUG after the first UTI is not recommended, since data do not support the use of antimicrobial prophylaxis to prevent recurrent febrile UTI in infants unless they have VUR
VCUG is indicated if ultrasonograms of the kidney and bladder reveal hydronephrosis, scarring, or other signs that high-grade VUR or obstructive uropathy may be present
VCUG should be performed if febrile UTI recurs, even if previous ultrasonographic findings were unremarkable

40. Complication

41. Complication of pyelonephritis :
focal inflammation of the kidney (focal pyelonephritis) or renal abscess.
scar formation. Approximately 10-30% of children with UTI develop some renal scarring; however, the degree of scarring required for the development of long-term sequelae is unknown.
Long-term complications of pyelonephritis are hypertension, impaired renal function, and end- stage renal disease.

44. British Journal of Urology volume 81 Page 8 - April 1998
The Final Urological Diagnosis of 426 live-born Infants with Significant Prenatally Detected Uropathy
British Journal of Urology volume 81 Page 8  - April 1998 44