Urinary Tract Infection (UTI) PDF

Urinary tract infection Prevalence (UTI) urinary tract infection (UTIs) occur in 1-3% of girls and 1% of boys. In girls, the 1st UTI usually occurs by the age of 5years with peak during infancy and toilet training. In boys, the most UTIs occur during the 1st year of life. UTIs are much...

Urinary tract infection Prevalence (UTI) urinary tract infection (UTIs) occur in 1-3% of girls and 1% of boys. In girls, the 1st UTI usually occurs by the age of 5years with peak during infancy and toilet training. In boys, the most UTIs occur during the 1st year of life. UTIs are much more common in uncircumcised boys especially in the 1st year of life. During the 1st year of life, the male to female ratio is 2.8-5.4:1. Beyond 1-2years, there is a female preponderance with a male – female ratio of 1;10. Etiology ! UTIS are caused by colonic bacteria in girls 75-90% of all infections are caused by Escherichia coli followed by klebsiela SPP and proteus SPP. Some series report that in boys > 1years of age, proteus is as common as E.coli. Others report a preponderance of gram-positive organism. Staph saprophytic enterococcus, adenovirus (cystitis) are pathogen in both sexes. Clinical manifestation ! 3 basic from of UTI are : 1.Pyelonephritis. 2.Cystitis. 3.Asymptomatic bacteriuria. 4.Focal nephronia. 5.Renal and perirenal abscess Clinical pyelonephritis ! is characterized by any or all of the following ; 1.Abdominal or flank pain. 2.Fever. 3.Malaise. 4.Nausea, vomiting and occasionally. 5.Diarrhea. Newborn may show nonspecific symptoms such as : Poor feeding. Jaundice. Irritability. Weight loss. Infants below 24 months of age may have fever without focus of infection (pyelonephritis is the most common serious bact. Infection in infant). Acute pyelonephritis may result in renal injury termed pyelonephritic scarring. Cystitis Indicate that there is bladder involvement symptoms include: 1.Dysuria. 2.Incontinence 3.Malodorous urine 4.Urgency. 5.Frequency. 6.Suprapubic pain. ** cystitis doesn’t cause fever and doesn`t result in renal injury. Malodorous urine isn’t specific for a UTI. Asymptomatic bacteriuria : A condition that results in appositive urine culture without any manifestation of infection. It is most common in girls. The incidence is 1-2% in preschool or school age, girls and 0.03% in boys. The incidence decrease with increasing age. This condition is benign and doesn’t cause renal injury. Pathogenesis and pathology All UTIS are ascending infection. The bact. Arise from fecal flora, colonize the perineum and enter the bladder via the urethra. In uncircumcised boys, the bact. pathogens arise from the flora beneath the prepuce. Cystitis occurs ! vesico – uretral reflux Which present congenitally or acquired due-to cystitis and dysfunction of detrusor muscle (primary or secondary). the bact reach the kidney ! Acute pyelonephritis. Rarely the renal infection may occur by hematogeous spread as in endocarditis or in some neonates. ✓ intra – renal reflux. Some compound papillae in upper and lower pole of the kidney allow urine to enter from renal pelvis to collecting tubules (normally there is antireflux mechanism by simple and compound papillae). ✓ Infected urine result in stimulation of an inflammatory or immunologic response, the result may cause renal injury and scarring. Diagnosis A UTI may be suspected based on the symptoms or finding on urinalysis or both, but culture is necessary for confirmation of diagnosis and appropriate therapy. ** In toilet trained child Amid stream urine sample if the culture shows : Great. than 100,000 colonies of single pathogen. or If there are 10,000 colonies and the child is symptomatic it is considered a UTI. ** In uncircumcised males, the prepuce must be retracted. In infants : the application of an adhesive, sealed, sterile collection bag after disinfection of the skin of genetelia. If ❑ The urinalysis result is positive. ❑ The patient is symptomatic and ❑ There is a single organism culture with a colony count > 100.000 there is a presumed UTI. If any of these criteria are not met confirmation of infection with a catheterized sample is recommended. in suprapubic or catheterize sample : if the culture shows more than 5o.ooo colonies of single pathogen or if there are 10.000 colonies and the child is symtomatic the child is consider to have UTI. Urinalysis : should be obtained from the same specimen as that cultured. ** Pyuria ( leukocytes in the urine) , suggest infection. Infection can occur in the absence of pyuria. Pyuria can occur without infection. So the finding is confirmatory than diagnostic. urine nitrite and leukocyte esterase. ** Microscopical hematuria (is common in acute cystitis). ** White blood cell casts in the urinary sediment suggests renal involvement. -- If the child is symptomatic a UTI is possible even the result of urinalysis is negative. ** with acute renal infection (pyelonephritis): Leukocytosis, neutrophilia and increase ESR, increase C-reactive protein , procalcitonine (all are nonspecific markers of inflammation). In renal abscess W.B.C increase to 20-25,000 /mm3 are common. ** Blood culture should be considered , sepsis is common in pyelonephritis particularly in infants and any children with obstructive uropathy. Imaging studies In children with clinical pyelonephritis (febrile UTI) a renal sonogram should be obtain to: 1. To demonstrating an enlarge kidney. 2. To demonstrate many but not all renal scar. 3. To rule out hydro nephrosis and structural abnormalities of urinary tract. 4. Large disparity may be an indication of renal growth impairment. 5. To detect nephronia (local pyelonephritis) and pyonephrosis. ❖ Normally the difference in renal length between the two kidneys is less than 1cm. In child with acute pyelonephritis, a small kidney may be enlarged because of the infection giving the erroneous impression that the kidneys are equal in size. Renal scanning DMSA scan in-patient with febril UTI for demonstrating parenchymal involvement. DMSA scan is performed in the presence of vesicoureteral reflux to assess whether renal scarring is present. In VSUG the most common finding is vesico-uretral reflux: 1.Precise grading of reflux. 2.Provide anatomic definition of bladder. 3.Radiological definition of urethra. Excretory urography ! isn’t as sensitive as the : 1.DMSA scan in demonstrating renal scarring. 2.Visualization of the collecting system in infant and young children is suboptimal. 3.Slight risk of contrast allergy. 4.Renal scar take 1-2years to appear on urogram. Host risk factors for UTI 1.Vesico uretcral reflux. 2.Obstructive uropathy (resulting in hydronephrosis increase the risk of UTIS because of urinary stasis). 3.Urethral instrumentation: During cysto urethrogram or non-sterile catheterization may infect the bladder with a pathogen. 4. In girls (UTIS often occur at the onset of toilet training because of voiding dysfunction that occur at that time). Voiding dysfunction may occur in the toilet trained child who void infrequently, the child is trying to retain urine to stay dry, yet the bladder may have un inhibited contraction, forcing urine out , the result may be high pressure, turbulent urine flow or incomplete bladder emptying both of which increase the like hood of bacteruria. Similar problem arise in school age child who refuse to use the school bathroom. Constipation can increase the risk of UTI because it may cause voiding dysfunction. 5. Neurogenic bladder. If there is incomplete emptying of bladder. The incidence of UTI in breast fed baby less than in those who fed formula. Indication for long – term prophylaxis (against reinfection). Neurogenic bladder. Urinary tract stasis. Obstruction. Reflux. Calculi. Using trimethoprim – sulfamethoxazole. Trimethoprim. Nitrofurantoin. At 1/3 of the normal therapeutic dose once a day. ** The most consequence of chronic renal damage caused by pyelonephritis are arterial hypertension and chronic renal in sufficiency. Treatment of UTIS! Acute cystitis ! should be treated promptly to prevent progression to acute pyelonephritis. If symptoms are sever ! a specimen of bladder urine is obtained for culture and treatment started immediately. If symptoms are mild or the diagnosis is doubtful treatment can be delayed until the results of culture are known and the culture can be repeated if the result is uncertain (colony count between 104 -105 colonies of Gram- ve organism). If treatment started before the result of culture and sensitivity are available , 3-5 days course of therapy with trimethoprim – sulfa methaxazol is effective against most strain of E-choli. 10mg|kg trimethoprim, 40 mg| kg sulfamethaxazole |24hr in tow divided doses. Nitrofurantoin 5-7 mg |kg| day in 3-4 divided doses is effective and has advantage of being active against klebsiela- entero bacter organism. Amoxicillin 50mg|kg|24hr also effective as initial treatment but has no clear advantage over sulfonamide or nitrofurantoin. ;in acute febrile infection suggesting of pyelonephritis 10-14 days course of broad spectrum antibiotics capable of reaching significant tissue levels is preferable. Children who are : 1.Dehydrated. 2.Vomiting. Or 3.Unable to drink fluids 4.are