uti mohammed swidek

1. By
Ezzat Kamel Amin
Assistant Prof. Pediatric Nephrology

2. -The most common bacterial infection in childhood
-Upper urinary tract infections (ie,
acute pyelonephritis)
may lead to
*Renal scarring,
*Hypertension,
*End-stage renal disease

3. Objective
-Def.
-Epidemiology.
-Pathogenesis
-ROUTES
-Urinary pathogen
-Risk factors
-Clinical presentation
-Investigations
-Treatment
•
-

4. Urinary tract infections can present as:
 Upper urinary tract infections  acute & chronic
pyelonephritis.
 Lower urinary tract infections  acute & chronic
cystitis & urethritis
 Asyptomatic bacteruria.
 Septicemia.
Urinary Tract Infections

5. Definations
Significant
bacteriuria
Colony count of >105/ml of a single species in a
midstream clean catch sample
Asymptomatic
bacteriuria Significant bac teriuria in absence of symptoms of UTI
Recurrent infection Second episode of UTI, usually within 6 months
Complicated UTI
Presence of fever >39 °C, systemic toxicity, persistent vomiting,
dehydration, renal angle tenderness, and raised creatinine
Simple UTI
UTI with low-grade fever, dysuria, frequency, urgency; none of
the symptoms of complicated UTI

6. Epidemiology
The risk of having a UTI
approximately 1–3 % in boys
3–10 % in girls.
During the first year of life, the male / female
ratio is 3–5/1.
Beyond 1–2 years, there is female
preponderance with male to female ratio of
1 : 10.

7. Pathogenesis
-The urinary tract is
a closed, sterile space
lined with mucosa.
-The main defense mechanism against UTI is
constant antegrade flow of urine
-This washout effect of the urinary flow
-
usually clears the urinary tract of pathogens
Antimicrobial characteristics of urine
(pH = 6.5 - 7.0)
- low urine pH.
- polymorphonuclear cells.
- Tamm-Horsfall glycoprotein, which inhibits bacterial adherence to
the bladder mucosal wall

8. ROUTES
*fecal-perineal-urethral rout : Retrograde
ascent
bladder - ureters - kidneys
*Nosocomial infection : Instruments.
*Hematogenous spread :systemic
infection or immunecompromised patients.
*Direct spread : Fistula from the bowel or vagina.

9. - Etiology
• UTIs are caused mainly by colonic bacteria.
• In girls, 75-90% of all infections are caused by
Escherichia coli, followed by Klebsiella spp and Proteus
• Some series report that in boys >1 yr of age, Proteus is
as common a cause as E. coli; others report a
preponderance of gram-positive organisms in boys.
• Staphylococcus saprophyticus and enterococcus are
pathogens in both sexes.

10. Risk factors
-Neonate/infant .
-Gender (females-short urethra). Pinworm
AAP. 2012)Benefit of circumcision.
)
-Foreskin .
-Fecal and perineal colonization & conistpaion.
-Anatomical anomalies and stones . labial adhesion
-Functional abnormalities , Neuropathic bladder, VUR
-Immunocompromised states (HIV).
-Sexual activity ,poor Hygiene.
-Bacteria with P fimbriae
-Wiping from back to front in girls

11. Clinical presentation
Sepsis(Jaundice, poor feeding , irritability ……..)
Newborns:
:
Infants
Symptoms of UTI are nonspecific like fever, hematuria , irritability,
vomiting, screaming during micturition, diarrhea, lethargy and FTT.
NB .
UTI should be suspected in younger children who present with
fever without apparent focus (unexplained fever).
Older children:
Urinary symptoms such as burning, urgency, frequency, flank pain,
turbid urine
odorous urine, recent onset of enuresis are common
and costovertebral angle tenderness .

12. Localization
Upper urinary tract infections
(Pyelonephritis)
- Acute: Fever, rigors & loin pain
- Chronic: - Prolonged fever
- May be hypertension
Acute pyelonephritis can result in
renal injury
(pyelonephritic scarring)
Lower urinary tract inf.
(Cystitis)
- Dysuria. , suprapubic pain ,
malodorous urine.- Frequency
- 2ry nocturnal enuresis. urgency,
- May be hematuria
Cystitis does not cause fever and
does not result in renal injury
.

13. Clinical presentation
Specific signs on examination:
Posterior urethral valves , Hypospadias,
:
Urinary stream
spine abnormalities (dimples, pits, or a sacral fat pad) :
Neurogenic Bladder
scrotal examination : epididymitis or epididymo-
orchitis
Genitalia: phimosis, labial adhesions,
Abd.examination:
palpable bladder and abdominal masses (palpable
kidneys) should be specifically looked for
Blood pressure measurement

14. Urinalysis .
Urine culture and sensitivity .
CBC . CRP .ESR .
Imaging studies .

15. For Non toilet-trained Infants and young children :
-Clean catch into a waiting sterile pot when the nappy
is removed
-Urine bag (high rate of contamination , unreliable
culture results)
-Catheterization :in and out catheter reliable and
more practical
- suprapubic aspiration :(Reserved for sick patients)

16. How you collect urine sample ?
For toilet -trained children :
Clean voided samples (mid-stream)
What is the technique ?
●For girls:
the labia should be spread and the perineum cleansed two to three
times with nonfoaming antiseptic solution or mild soap. .
●For boys:
the meatus should be cleansed in a similar fashion.
The foreskin should be retracted before cleansing .
Cleansing the perineum with soap prior to urine collection
decrease the rate of contamination

17. Urinalysis
Microscopic Finding:
*pyuria:
white blood cells>5 / (HPF) in a centrifuged sample
> 10 white cells/HPF in an uncentrifuged sample of urine
is seen in the majority of The patients with UTI
Causes of sterile pyuria:
Dehydration
urinary tract trauma ,partially treated bacterial UTIs, viral infection
Renal T.B
Early glomerulonephritis
*Hematuria: is common in acute cystitis
Urine cultures should be sent to the laboratory even if urinalysis results are
inconclusive.
20% of pediatric patients with UTI have normal urinalyses results.

18. Diagnosis
The gold standard for diagnosis of UTI is
the urine culture.
children with a high likelihood of UTI,
a urine culture is required.
In children with a low likelihood,
-Negative dipstick in a clear urine reduces the need for
culture.
-If the dipstick shows (+) LE and/or (+) Nitrites, send a urine
culture.
NB *The dipstick is not sufficient to diagnose UTI’s
because false positives can occur.

19. Leukocyte Esterase and Nitrites
LE is produced from the breakdown of leukocytes.
Not always indicative of infection
Vaginitis/vulvitis can lead to inflammation without
infection + LE
sensitivity 83 %
specificity of 78 % to detect UTI
Nitrites are produced by bacteria
that metabolize nitrates:
E. coli, Klebsiella, Proteus (GNRs)
-Much more predictive of UTI
-GPCs do not produce nitrites
sensitivity of 53 %
specificity of 98 % in detecting UTI

20. Urinary Tract Infection:
Diagnostic criteria
Method of
collection
Colony count
Probability of
infection (%)
Suprapubic
aspiration
Any number of
pathogens 99
Urethral
catheterization >5 × 104 CFU/ml 95
Midstream
clean catch >105 CFU/ml 90–95

21. Imaging
- Localize upper urinary tract infections by:
 Renal ultrasound.
 Renal DMSA scan.
- For recurrent urinary tract infections:
 Renal ultrasound for obstruction.
 Voiding cysturethrography for vesico ureteric reflux.
 Renal functions tests.

22. Recurrent UTI
The risk factors for recurrent UTI are:
Girls
Age <6 months
Phimosis/labial adhesions
Obstructive uropathy ,renal stones, FB.Undertreatment
Voiding dysfunction
Constipation
High-grade vesico-ureteral reflux (VUR)

23. Treatment:
1- Adequate hydration.
2- Antibiotics: (Empirical antibiotics)
Infant & severe infection

i.v. ampicillin & 3rd generation
cephalosporin
Well child

Oral cotrimoxazole & amoxicillin
Cefixime
Till results of culture and sensitivity

24. How do you give antibiotics?
-Parenteral antibiotics are indicated in complicated UTI and given for
the first 2–3 days followed by orally administered antibiotics for 7–14
days as per the culture sensitivity report .
-
In acute febrile infections suggesting pyelonephritis, a 10- to 14-day course
of broad-spectrum antibiotics.
• If treatment is initiated before the results of a culture and sensitivities
are available, a 3- to 5-day course of therapy with
trimethoprim-sulfamethoxazole (TMP- SMX) or trimethoprim is
effective against most strains of E. coli.
• Nitrofurantoin (5-7 mg/kg/24 hr in 3-4 divided doses) also is effective
and has the advantage of being active against Klebsiella and Enterobacter
organisms.
• Amoxicillin (50 mg/kg/24 hr) also is effective as initial treatment but has
no clear advantages over sulfonamides or nitrofurantoin.

25. NICE guidelines for antibiotic treatment
Age <3 months…………………IV antibiotics for 2-4 d.then switch to
oral antibiotics if clinically improved
Age >3 months …………………..Oral antibiotics for 7-10 d.
With upper UTI IV antibiotics for 2-4 d. if vomiting
then oral for a total of 10 days
Age >3 months ……………………Oral antibiotics for 3 d.
With lower UTI
If a child is on prophylaxis…………………Change antibiotics
(oxford pediatric
nephrology)

26. 3- Follow up
 Urine culture after 1 week to ensure recovery.
Further cultures to detect recurrence (mostly
asymptomatic) in the first 6-12 months after an infection :
in presence of risk factors ( VUR , Obstruction )
Every month for 3 months .
Every 3 months for 6 months .
Twice a year .
A urine culture during treatment almost invariably is negative

27. 4- Prevention:- for recurrent urinary tract infections
1. Remove underlying risk factor e.g stones, constipation.
2. Adequate hydration.
3. Adequate bladder emptying.
4. Cranberry juice which prevents bacterial adhesion
5.Avoid Wiping back-to-front causes UTIs
6. probiotics which replaces pathologic urogenital flora
7.Avoid tight underwear
8. UTI prophylaxis.

28. Chemoprophylaxis
Preventing recurrence of infection and its complications in debate
10 to 30 % of children with UTI will have at least one more episode.
The majority of recurrences will occur within the first 12 months of
infection.
The risks for renal damage include
age less than 6 months at the initial UTI,
the presence of dilating VUR.
•
. The wide-spread clinical practice of routine antimicrobial
prophylaxis is now being questioned.
The evidence that prophylactic antibiotics prevent recurrent UTI in
children without VUR is weak.
Guidelines from AAP, recommend using long-term antibiotic
prophylaxis
For high risk conditions eg. neurogenic bladder , and VUR
Usually for patients below 3 years.

29. Drug mg/kg/day Remarks
Cotrimoxazole 1–2 (trimethoprim)
Avoid in infants <3
months age and G6PD
deficiency
Nitrofurantoin 1–2
Gastrointestinal upset;
avoid in infants <3
months age,G6PD
deficiency and renal
insufficiency
Cephalexin 10
Drug of choice in first 3
months of life
Cefixime 2
In select circumstances
only
Antibiotic UTI Prophylaxis

30. Take Home Message
*The gold standard for diagnosis of UTI is
the urine culture
Suprapubic aspiration : Any number of pathogens
Urethral catheterization : >5 × 104 CFU/ml
Midstream clean catch : >105 CFU/ml*
*fecal-perineal-urethral route is the commonest route
*The commonest pathogens in girls E coli ,Pseudomonas ,Klebsiella
Proteus is common in boys.
*UTI should be suspected in younger children who present with (unexplained
fever).
Cystitis does not cause fever and does not result in renal injury
*Prevention:- for recurrent urinary tract infections
1. Remove underlying risk factor e.g stones, constipation.
2. Adequate hydration.
3. Adequate bladder emptying.
4-Chemoprophylaxis