TERMINOLOGY

• UTI• Bacteruria• Acute pyelonephritis• Acute cystitis • Unspecified UTI(10-20%)• Asymptomatic (or covert)

bacteruria (ABU)

TERMINOLOGY (cont.)

•Chronic pyelonephritis (reflux nephropathy)

•Relapse •Reinfection •Recurrent infections •Persistant infection

EPIDEMIOLOGY- In 1st year of life : Acute

pyelonephritis - In 2-6 years of age : Acute cystitis - Boys>Girls (2-3times ) - After 6 months of age: Girls>Boys- Recurrence rate : girls15%

Boys 15% in 1st year

CAUSES •E. coli (80-90%)•Klebsiella•Proteus (30% boys)•Staph. Saprophyticus

(adolescents)•Enterococci, pseudomonas,

S.aureus or epidermidis, H.influenza& group B.streptococci.

Pathogenesis

Periurethral Bacterial flora

•Enterobacteria & enterococci (after the age of 5 years, are rare)

•In small girls: E. coli•In boys: E. coli(6mos), proteus

•Ascending bacteria •Bacterial properties •Tissue properties•Neurogenic bladder •Anatomical abnormalities •Cellular & immunologic factors •Trauma, urethral catheteriztion

Host Resistance •Bladder defense mechanisms •Incomplete bladder emptying (>5cc recurrence rate 75% in 1 year)(0-5cc recurrence rate 17% in 1 year)•Antiadherence mechanisms

Clinical presentation• Neonatal period• Renal tenderness: 4-5 years old • Fever of 38ocAcute bacterial

cystitis • Fever of 38.5oc upper urinary

tract involvement

Clinical Presentation• Age and gender dependent• 0 - 2 months:

• Fever• 2 mo.– 2 y/o:

• Fever ( >38 C)• Irritability•Vomiting and Diarrhea•Decrease appetite•Between 1-2 y/o = crying on urination, foul smelling odor

Clinical Presentation• 2 y/o – 6 y/o:

•Systemic symptoms•Fever•Flank or back pain•Urgency, urinary incontinence,

dysuria•Suprapubic or abdominal pain•Foul smelling odor

• > 6 y/o and adolescents:•Same as above

Urethritis

• In female infants •Part of a

diaper dermatitis

• In adolescent girls and boys •Presenting

sign of STD

• In pre-school and school age girls • Part of “non-specific”

vulvovaginitis • Generally

environmental• Bubble bath• Nylon panties (also

biker shorts, leotards, bathing suits)

• Poor hygiene (not wiping, wiping back to front)

• Overzealous hygiene• Use of baby powder,

perfumes

Symptoms of urethritis• Dysuria• Reluctance to void• Perineal discomfort, erythema• May be associated with vaginal

irritation and erythema in girls• In older boys, urethral discharge• In adolescent girls associated

with PID symptoms

Cystitis

•Afebrile usually•Frequency•Enuresis•Dysuria•Reluctance to void

Pyelonephritis

• Usually associated with fever and systemic signs 2° renal parenchymal inflammation

• Older children •Flank pain or abdominal pain

• Younger children•Fever, irritability, vomiting, poor

feeding

Diagnosis

Methods of urine collection :

õ Bag õ Absorbent pad õ Suprapubic õ Catheterization õ Midstream

Culture of urine :• Calibrated loop • Dipslide culture

Suprapubic urine: any growth Catheter urine: 1000-10000

CFU/ml (50000 CFU/ml)Mid stream urine: >105 CFU/ml

The probalility of true bacteruria in single culture : (70-80%).

Site of infection - Leukocytosis - ESR- CRP(+Ve)- LDH- Procalcitonin

Other urine findings Urine PHSpecific gravity (Fasting)Proteinuria (RNP)Hematuria (macroscopic in 20-25%

of those with acute cystitis)Nitrite test (False+Ve)WBC castPyuria(80-90%)

Leukocyte Esterase• Has to accumulate in urine• Insufficient accumulation possible

in small infants who void frequently

• Infants <3 months old may not have mature enough immune system to induce leukocytes in urine (beware neutropenia on CBC)

Nitrites• By-products of E. coli and other

lactose fermenters (glucose digestion)

• Insufficient accumulation possible in small infants who void frequently

• Insufficient accumulation possible in older child during the day and in older patient who has significant frequency

• If positive, highly suggestive of UTI (high specificity)

Sensitivity and Specificity of Components of the UA

TestSensitivity%

(Range)Specificity%

(Range)

Leukocyte esterase

Nitrite

Leukocyte esterase or nitrite positiveMicroscopy: white blood cells

Microscopy: bacteria

Leukocyte esterase or nitrite orMicroscopy positive

83( 67.94)

53( 15-82)

93( 90-100)

73( 32-100)

81( 16-99)

99.8( 99.100)

78( 64-92)

98( 90-100)

72( 58-91)

81( 45-98)

83( 11-100)

70( 60-92)

Renal imaging

•Ultra sonography •99mTc-DMSA(sensitivity 86% & specificity of 91%)

Imaging

•Ultrasound•Detects structural malformations

•Helpful in detecting the ureteral dilatation of advanced stage reflux (Grades III-IV)

•Can be done imediately

Imaging• VCUG (CONTROVERSIAL)

•Bladder is fully filled via catheter with radiopaque liquid

•Child is asked to void•During voiding, look under

fluoroscopy for reflux•Can be done after 48 hrs of

receiving antibiotics•Can be done 4 – 6 weeks after UTI

Imaging• Radionuclide Cystogram (RNC)

•Nuclear study comparative to VCUG

•Diagnoses obstruction•Only for girls•May use Lasix

• DMSA scan•Looks for scarring•Differentiates acute pyelo v.s.

cystitis•Done at 6 mo

Imaging

• In children with a second febrile UTI who previously had a negative upper tract evaluation, a VCUG is indicated, because low-grade reflux predisposes to clinical pyelonephritis.

• In children with ≥1 infection of the lower urinary tract (dysuria, urgency, frequency, suprapubic pain), imaging is usually unnecessary.

Imaging

• Instead, assessment and treatment of bladder and bowel dysfunction is important.

• If there are numerous lower urinary tract infections, then a renal sonogram is appropriate, but a VCUG rarely adds useful information.

ALTERNATIVE RECOMMENDATIONS FOR UTI

• In 2007, the NICE (National Institute for Health and Clinical Excellence, UK) guidelines:

These recommendations divide children into those <6 mo, 6 mo to 3 yr, and

>3 yr of age.

ALTERNATIVE RECOMMENDATIONS FOR UTI

• The clinical categories are separated into those that respond to treatment within

48 hours, recurrent UTI, and atypical UTI (sepsis, non-E. coli UTI, suprapubic mass, elevated serum creatinine, hypertension).

• The recommendations include upper tract imaging with a renal sonogram and DMSA scan for all <6 mo with a UTI and all children <3 yr with an atypical or recurrent UTI.

ALTERNATIVE RECOMMENDATIONS FOR UTI

• For children >3 yr, a DMSA scan is recommended only for recurrent UTI.

• A VCUG is recommended only in children <6 mo.

• In 1999, the American Academy of Pediatrics released guidelines for management of children 2 m to 2 yr with a febrile UTI.

• This guideline recommended a renal sonogram and VCUG or radionuclide cystogram.

We suggest routine imaging (RUS and VCUG) for:

• Girls younger than three years of age with a first UTI (children older than three years are more reliably able to verbalize urinary symptoms)

• Boys of any age with a first UTI• Children of any age with a febrile UTI• Children with recurrent UTI (if they have not

been imaged previously)• First UTI in a child of any age with a family

history of renal disease, abnormal voiding pattern, poor growth, hypertension, or abnormalities of the urinary tract

TREATMENT

•Antibiotic treatment

Usual indications for hospitalization include:

• Age <2 months• Clinical urosepsis or potential

bacteremia• 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

Antibacterial prophylaxis

• In patients at risk for developing renal scarring

• Those with VUR with dilatation of the upper urinary tract

• Those who are prone to develop recurrent acute pyelonephnitis

• Repeated attacks of cysititis

Risk factors

• Obstruction • Reflux with dilatation • Age • Delay of treatment • Number of pyelonephritic attacks • Uncommon bacteria ( non –E. coli)

Antibiotics for low –dose prophylaxis

Nitrofurantion 1mg/kg/ 24hr Klebsiella

Trimethoprim 0.5mg/kg /24hr

S.Epidermidis

TMP/SMX0.5mg/kg/ 24hr

Enterobacter

Cefadroxil 3-5mg/kg /24hr

Enterococci

Ciprofloxacin1mg/kg /24hrEnterococci

INVESTIGATIONS

• Ultrasonography • Urography• VCUG• DMSA Scan • DTPA or MAG-3 Scan

VCUG Evaluation

• Any child with a febrile UT1• In children younger than 3years

[<5yrs]• Boys of any age • Girls with 2nd UTI

Early Follow-UP

• Sterile urine: 24hrs • Fever & other symptoms: 2-

3days• CRP<20mg/l: 4-5days• ESR: 2-3 WKS• Specific Gravity: 2-3mos

Follow Up

• 48hrs after treatment • 2-7 days after end of

treatment • Every 1-2mos for 6mos• Every 2-3mos for 6mos• Every 6mos for 1year

Asymptomatic Bacteruria (Covert bacteruria)

CBladder dysfunction

Multifactorial pathogenesis

Treatment of children with ABU

CHistory: Bladder &Bowel

Function

CP/E

•No treatment