UTI Flashcards
causative organism
🔺 The urinary tract and urine are normally sterile.
🔺E. coli, ascending from bowel flora, accounts for 90% of first infections and 75% of recurrent infections.
*Ninety percent of nephritogenic E. coli possess P-fimbriae, which facilitates adherence to uroepithelial cells via cell surface receptors and P blood group antigens.
*Individuals with high-level expression of P1 blood group antigen are predisposed to pyelonephritis and bacteremia, as well as recurrent UTIs.
🔺Other bacteria commonly causing infection include :
🔹Klebsiella
🔹Proteus
Proteus infection(more in boys,possibly because of its presence under the foreskin ,& predisposes to the phosphate stones formation
🔹Enterococcus
🔹 Pseudomonas.
Pseudomonas infection may indicate astructural abnormality in the urinary tract
🔹Staphylococcus saprophyticus
is associated with UTI in some children and in sexually active adolescent girls.
epidemiology of UTI
🟢 Approximately 3% of girls and 1% of boys have a UTI by 11 years of age.
🟢The prevalence of UTIs varies with age;
➢During the 1st yr of life, the male >female
➢Beyond 1-2 yr, there is a female preponderance,.
🟢In boys, most UTIs occur during the 1st yr of life; UTIs are much more common in uncircumcised boys, especially in the 1st yr of life.
🟢In girls, the first UTI usually occurs by the age of 5 yr, with peaks during infancy and toilet training.
risk factors of UTI
🔴 Non-modifiable:
〰️female gender
〰️Caucasian
〰️previous UTI
〰️family history
🔴Modifiable:
➰urinary tract abnormalities (VUR, neurogenic bladder, obstructive uropathy, posterior urethral valve)
➰dysfunctional voiding
➰repeated bladder catheterization, ➰uncircumcised males
➰Labial adhesions
➰sexually active
➰constipation
➰toilet training
🔴Obstruction to urine flow and urinary stasis is the major risk factor and may result from
1.Anatomic abnormalities
2.Nephrolithiasis
3.Renal tumor
4.Indwelling urinary catheter
5.Ureteropelvic junction obstruction
6.Megaureter
7.Extrinsic compression
8.Pregnancy.
major risk factor for UTI
Obstruction to urine flow and urinary stasis is the major risk factor and may result from
1.Anatomic abnormalities
2.Nephrolithiasis
3.Renal tumor
4.Indwelling urinary catheter
5.Ureteropelvic junction obstruction
6.Megaureter
7.Extrinsic compression
8.Pregnancy.
VU reflux & scarring
♾️Vesicoureteral reflux, whether primary (70% of cases) or secondary to urinary tract obstruction, predisposes to chronic infection and renal scarring.
♾️Scarring also may develop in the absence of reflux.
clinical features of UTI
neonate
2m-2yr
preschool and school
adolescent
⭕️Neonates
often present with nonspecific symptoms of jaundice, hypothermia or fever, poor feeding, vomiting, and failure to thrive.
⭕️Infants and young children aged 2 months to 2 years
often present with nonspecific symptoms of fever lasting longer than 48 hours, as well as with poor feeding, vomiting, and diarrhea. Their urine may be malodorous; hematuria may be noted.
⭕️Preschoolers and school-age children present with fever for greater than 48 hours. They may complain of abdominal pain or flank pain. Vomiting, diarrhea, and anorexia may be present. Their urine is typically malodorous, and hematuria may be noted.
•Voiding-related symptoms including enuresis, dysuria, urgency, and frequency, may occur.
⭕️ Adolescents
are most likely to present with the classic adult symptoms of fever, often with chills, rigors, and flank pain. They may have abdominal and suprapubic pain, along with voiding-related symptoms of frequency, dysuria, and hesitancy. Their urine is most often malodorous, and hematuria is variably present
indications of urine test in infants & children
1-s&s of UTI
2-unexplained fever
3-an alternative site of infection but who remain unwell
Methods of collection of urine sample
1️⃣midstream ,clean-catch technique
(for older children and adolescents) is considered significant with bacterial growth of greater than 100,000 cfu/mL;
2️⃣catheterization
is considered significant with bacterial growth of greater than 10,000 cfu/mL;
3️⃣suprapubic aspiration
Any bacterial growth indicates A UTI
4️⃣Perineal bags for urine collection are prone to contamination and are not recommended for urine collection for culture(for screening)
WHAT FACTORS CAN CAUSE LOW COLONY COUNTS DESPITE SIGNIFICANT URINARY INFECTION?
1.High-volume urine flow
2.Recent antimicrobial therapy
3.Fastidious c and slow-growing organisms (e.g., enterococci, Staphylococcus saprophyticus)
4.Low urine pH (<5.0) and specific gravity (<1.003)
5.Bacteriostatic agents in the urine
6.Complete obstruction of a ureter
7.Chronic or indolent infection
8.Use of inappropriate culture techniques
investigations of UTI
1 🔵 Urinalysis
showing pyuria (leukocyturia of >10 WBC/mm3) suggests infection,
2 🔵 Urinary dipstick tests
that combine both the leukocyte esterase and nitrite have sensitivity of 88% and specificity of 93% for detecting a UTI.
Either test used alone has poor sensitivity.
3 🔵 urine culture
4 🔵 imaging
Ultrasonography
•VCUG ▶️ vesicoureteral reflux
•Radionuclide (DMSA) ▶️ renal scarring
•Cystography
•Renal nucleotide scans
•CT or MRI
WHAT FACTORS INCREASE THE RISK FOR PERMANENT RENAL DAMAGE IN CHILDREN WITH UTIS?
1.Younger age
2.Obstruction
3.VUR
4.Recurrent infections
5.Pyelonephritis
6.Nephrolithiasis
7.Delay in diagnosis and initiation of therapy
WHICH DISEASES IN ADULTS HAVE BEEN ASSOCIATED WITH PYELONEPHRITIS IN CHILDREN?
A. Hypertension
B. Toxemia in pregnancy
C. End-stage renal disease
D. All of the above
E. No clue
Empirical therapy should be initiated in
- for symptomatic children
- for all children with a urine culture confirming UTI.
Antibiotics (emprical)
⭕️ 1- febrile child
🔹Oral third-generation cephalosporins (cephalexin,cefixime, cefpodoxime)
🔹TMP-SMZ (7-10 days)
🔹amoxcillin/clavulanic acid (7-10 days)
⭕️2-afebrile child
the same AC but for 2-4 days
⭕️Children with high fever or other manifestations of acute pyelonephritis often are hospitalized for initial treatment with parenteral antibiotics, such as
➰cefotaxime
➰ceftriaxone
➰cefipime
➰ceftazidime.
⭕️Ifaged<3months or Febrile and/or very Unwell and unable toTake oral antibiotic give :
iv ampcillin andgaramycin or iv claforan,cefipime or ceftazidime for 2-3 days then change to oral according to culture result to complete 7-14 days
التسلسل حسب الاقوى
- anpicilin
- vancomycin
- meronem
Mx for Children with high fever or other manifestations of acute pyelonephritis
often are hospitalized for initial treatment with parenteral antibiotics, such as
🔺cefotaxime (claforan) 💊kidney metabolism
🔺ceftriaxone 💊 liver metabolism و مننطي اول 3 أشهر
🔺cefipime
🔺ceftazidime.
