URINARY TRACT INFECTION in children : summarized

URINARY TRACT INFECTION

Dr Sadia Hayat

PREVALANCE AND ETIOLOGY :

Urinary tract infections  caused primarily by colonic bacteria

·        E.Coli 75-90%

·        Klebsiella

·        Proteus

·        Gram positive (staphylococcus saprophyticus  and enteroccoci )

·        adenovirus and other viral infections (hemorrhagic cystitis)

During first year of life infection is more common in boys ,beyond one year female preponderance .

CLINICAL MANIFESTATIONS AND CLASSIFICATION :

3 basic forms of UTI

1.     CLINICAL PYELONEPHRITIS :bacterial infection involving renal parenchyma , characterized by abdominal,back or flank pain ;fever ;malaise nausea ;vomiting and diarrhea .fever may be the only manifestation 

-         New borns can show nonspecific symptoms such as poor feeding ,irritability , jaundice and weight loss .

2.      CYSTITIS : symptoms include dysuria ,urgency , frequency ,suprapubic pain ,incontinence and malordorous urine .not associated with fever and doesnt result in renal injury.

                    -acute hemorrhagic cystitis:caused by E.Coli .It has also been

                   attributed to adenovirus types 11 and 21 ,more in boys, self                                                          limitig , self limiting ,hemturia lasting 4 days .

3. Asymptomatic Bacteriuria:condition in which there is positive urine culture without any manifestation of infection ,more common in girls .

PATHOGENESIS AND PATHOLOGY :Ascending infections arising mainly from fecal flora ,colonize the perineum and enter the bladder via urethra .Acute pyelonephritis occurs if bacteria ascend from bladder to kidney ,infected urine stimulate immunologic and inflammatory response resulting in renal injury and scarring .

-Risk Factors for Urinary Tract infection :

Female gender	wiping from back to front in girls
uncircumscribed male	pinworm infestation
vesicoureteral reflux	Constipation
Toilet training	bacteria with p-fimbrae
voiding training	neuropathic bladder
obstructive uropathy	sexual activity
urethral instrumentation	Pregnancy

      

Diagnosis:

1.clinical symptoms and signs

2.urinalysis

3.urine culture :necessary for confirmation and appropriate therapy.

if culture shows more than 50,000 colonies of single pathogen, or if there are 10,000 colonies and child is symptomatic child is considered to have uti

4.Non specific markers of inflammation :

including leukocytosis, neutrophillia, elevated ESR , procalcitonin, C-reactive protein .

5.Blood culture :

particularly in children with obstructive uropathy and infants .

Treatment :

1.Acute cystitis should be treated promptly if symptoms are severe ,presumptive treatment started before the results of culture , a 3-5 day course of trimethoprim-sulfamethoxazole (TMP-SMX) or trimethoprim is effective against E.Coli . Amoxicillin (50 mg /kg / day ) is also effective .

2. In acute febrile illness suggesting Clinical pyelonephritis a 7-14 day course of broad spectrum antibiotics

3.children who are dehydrated have vomiting ,unable to drink fluids , 1month of age or younger shoul be admitted and treated with ceftriaxone (50-75mg /kg /24hr ) or cefotaxime or ampicillin with an aminoglycoside such as amikacin.

4. third generation cephalosporin such as cefixime is effective against gram negative organisms as well except pseudomonas .

5,flouroquinolones such as ciproflxacin and levofloxacin are  effective against resistant organisms particularly psudomonas but not routinely used due to potential cartilage damage .

6.In children with recurrent UTI predisposing factors should be identified ,behavioural modification is also needed in some cases.