UTI

URINARY TRACT

INFECTIONS
(UTI)

• UTI occur in 1% of boys and 1-3% of girls.

• During the 1st year of life males > females (especially uncircumcised males) with a male: female ratio of 2-5:1.
• Beyond 1-2 yr of age, the females > male with male: female ratio of 1:10.
Prevalence:

• In girls,

• 75-90% caused by Escherichia coli,
• Then Klebsiella spp. and Proteus spp.
• In boys,
• the E. coli is the most common M.O
• In boys >1 yr Proteus and E. coli are equal as a cause of UTI.
• Adenovirus and other viral infections can occur in both sexes, especially as a cause of hemorrhagic cystitis.
Causative M.O. (Etiology):


• UTIs are caused primarily by colonic bacteria.
• Nearly all UTIs are ascending infections.
• The bacteria arise from the fecal flora, colonize the perineum, and enter the bladder via the urethra.
• In uncircumcised boys, the pathogens arise from the flora beneath the prepuce.
Pathogenesis:

• In some cases, the bacteria causing cystitis ascend to the kidney to cause pyelonephritis.
• Rarely, renal infection occurs by hematogenous spread, as in endocarditis or in some neonates.

Risk factors of UTI:

• Female gender
• Uncircumcised male
• Vesicoureteral reflux
• Toilet training
• Voiding dysfunction
• Obstructive uropathy
• Urethral catheterization.
• Wiping from back to front in girls

• Tight clothing (underwear)

• Pinworm infestation
• Constipation
• Anatomic abnormality (labial adhesion)
• Neuropathic bladder
Risk factors of UTI:


• There are 3 basic forms of UTI:
• Pyelonephritis
• Cystitis
• Asymptomatic bacteriuria.

• Focal pyelonephritis (nephronia) and renal abscesses are less common.

Classification of UTIs:

• Acute pyelonephritis is infection of renal parenchyma.

• Pyelitis Is infection of renal pelvis without involvement of renal parenchyma.
• Pyelonephritic scarring is the renal injury resulting from acute pyelonephritis.
Pyelonephritis:

• Abdominal, back, or flank pain

• Fever (may be the only manifestation)
• Malaise; nausea; vomiting; and, occasionally, diarrhea
• Newborns can show nonspecific symptoms such as poor feeding, irritability, jaundice, and weight loss.
Clinical features of pyelonephritis

• Renal abscess can occur following a pyelonephritic infection caused by the usual uropathogens or may be secondary to hematogenous infection (S. aureus).


• Dysuria
• Urgency
• Frequency
• suprapubic pain
• Incontinence
• mal-odorous urine.
• Cystitis:
• DOES NOT cause fever
• DOES NOT cause renal injury
• Mal-odorous urine is NOT specific for UTI.
Cystitis

• Acute hemorrhagic cystitis

• Often caused by E. coli
• Less commonly by adenovirus types 11 and 21.
• Adenovirus cystitis is more common in boys; it is self-limiting, with hematuria lasting approximately 4 days.

• Is a positive urine culture without any manifestations of infection.

• It is most common in girls and is rare in boys.
• The incidence is <1% in preschool and school age girls.
• It is benign condition and does not cause renal injury, except in pregnant women, in whom if left untreated, can result in symptomatic UTI.
Asymptomatic bacteriuria


• Based on the symptoms or findings on urinalysis, or both.
• Urine culture necessary for confirmation and appropriate therapy.
Diagnosis of UTI:

• Midstream urine sample:

• Used in toilet trained children.
• In female, the introitus should be cleaned before obtaining the urine specimen
• In uncircumcised male, the prepuce must be retracted before obtaining the urine specimen.
2. suprapubic aspirate or urethral catheterization
• Used in non-toilet trained child
Ways of urine collection:

3. Collection bag:

• Adhesive, sealed, sterile bag
• Applied to genitalia after disinfection of the skin
• The results of urine culture dependable only if the culture is negative or if a single uropathogen is isolated.
• Positive culture of multiple pathogens can result from skin contamination especially in girls and uncircumcised boys.

• The collected urine should be examine and cultured as early as possible

• If the urine remain at room temperature for >60 min will cause overgrowth of a minor contaminant.
• Refrigeration is a reliable method of storing the urine until it can be cultured.


• Positive nitrates and leukocyte esterase tests.
• Microscopic hematuria is common in acute cystitis, but microscopic hematuria alone does not suggest UTI.
• WBC casts suggest renal involvement (pyelonephritis).
Positive results of urinalysis:

• If the child is asymptomatic and the urinalysis is normal, the UTI is unlikely.

• If the child is symptomatic, the UTI is possible even if the urinalysis result is negative.

• Is refer to the presence of leukocytes on urine microscopy.

• It suggests infection, but infection can occur in the absence of pyuria.
• It is confirmatory more than diagnostic.
• Pyuria can be present without UTI.
Pyuria:

It mean positive leukocytes in urinalysis, with negative urine culture

Causes:
• Partially treated bacterial UTIs
• Viral infections
• Renal tuberculosis
• Renal abscess
• UTI in the presence of urinary obstruction
• Urethritis as a sexually transmitted infection
• Inflammation near the ureter or bladder (appendicitis, Crohn disease)
Sterile pyuria


• In suprapubic or catheter sample: the child is considered to have a UTI if :
• The culture shows >50,000 colonies of a single pathogen
or
• There are 10,000 colonies of a single pathogen and the child is symptomatic.
Positive results of urine culture:

• In a collection bag sample: the child is considered to have a UTI if:

• The urinalysis result is positive,
• The patient is symptomatic,
AND
• There is a single organism cultured with a colony count >100,000.

If any of these criteria are absent, confirmation of infection with a catheterized sample is indicated.

• should be treated promptly to prevent progression to pyelonephritis.

• If the symptoms are severe, the treatment is started before getting results of the culture.
• If the symptoms are mild or the diagnosis is doubtful, treatment can be delayed until the results of culture are known.
• The culture can be repeated if the results are uncertain.
Treatment of UTI:
Acute cystitis:


Empirical antibiotic therapy are:
• Trimethoprim-sulfamethoxazole (TMP-SMX) or trimethoprim for 3-5 days are effective against E. coli.
• Nitrofurantoin (5-7 mg/kg/24 hr in 3-4 divided doses) is effective and has advantage of being active against Klebsiella and Enterobacter organisms.
• Amoxicillin (50 mg/kg/24 hr) also is but has a high rate of bacterial resistance.

• Indications of hospital admission are:

• Dehydration
• Vomiting
• Inability to drink fluids
• Patients 1 mo of age or younger
• Complicated infection
• Possibility of urosepsis.
Clinical pyelonephritis (febrile UTI):

Treatment of pyelonephritis:

• I.V. fluids .
• Broad spectrum antibiotics for 7-14 days, these AB are:
• I.V. ceftriaxone (50-75 mg/kg/24 hr) or cefotaxime (100 mg/kg/24 hr).
• I.V. ampicillin (100 mg/kg/24 hr) with aminoglycoside ( gentamicin 3-5 mg/kg/24 hr in 1-3 divided doses).
• Nitrofurantoin.
• Oral fluoroquinolone (e.g. ciprofloxacin and Levofloxacin )


• Renal or perirenal abscess
• Infection in obstructed urinary tracts

Require surgical or percutaneous drainage PLUS antibiotic therapy.

• Small abscesses may be treated without drainage.

• Identification and treatment of the underlying cause:

• Bladder–bowel dysfunction,
• Severe constipation
• Neuropathic bladder
• UT stasis and obstruction
• severe VUR
• urinary calculi
Management of Recurrent UTI:

• Prophylactic antibiotics:

• Trimethoprim or nitrofurantoin at 30% of the normal therapeutic dose once a day.
• TMP-SMZ, amoxicillin, or cephalexin can also be effective, but the risk of break through UTI may be higher because of bacterial resistance.
Management of Recurrent UTI:
Thank you for your attention


Vesicoureteral Reflux (VUR)

• (VUR) is the retrograde flow of urine from the bladder up to the ureter or even up to the kidney.
• It is may be familial
30% to 40% of siblings of a child with VUR also have VUR

Effect of VUR:

• It cause:
• hydrodynamic pressure on the kidney during voiding
• predispose to UTI due to incomplete emptying of the bladder and ureter.
• This will facilitate the bacterial transport to the kidney causing pyelonephritis.
• pyelonephritis can result in renal injury or scarring termed Reflux nephropathy, which if it severe will cause end-stage renal disease.

Classification:

• Primary VUR: due to congenital incompetence of the ureterovesical (UV) junction.
• Secondary VUR:
• distal bladder obstruction
• duplications of the ureter
• neurogenic bladder
• cystitis
• acquired bladder obstruction e.g. foreign body or vesical stones.


Grading:
By contrast voiding cystourethrogram (VCUG)
G I G II G III G IV G V

• Incidence of renal scarring with VUR

• GI and GII 15%
• G IV or V 65%
• Grade I or II VUR is likely to resolve without surgical intervention
• G IV or GV < 50% resolve spontaneously.

• VUR is often identified during radiologic evaluation after a UTI .

• The younger the patient with UTI, the more likely to have VUR.
• There are no clinical signs can differentiate children with UTI who have VUR from those without VUR.
Clinical manifestations:

• Long-term prophylactic AB (trimethoprim-sulfamethoxazole or nitrofurantoin)

Indications:
• Mild to moderate VUR (controversial).
• High-grade VUR and/or recurrent symptomatic UTI
• Patient younger than one year of age.


2. Surgical correction: In sever VUS
Treatment:

• Hypertension

• Chronic kidney disease (CKD).
Complications of VUR:
Thank you for your attention
with
my best wishes for great success