Presentation on theme: "Uti in children. Introduction Pediatric UTIs often signal an underlying genitourinary tract abnormality Can lead to renal scarring with resultant hypertension."— Presentation transcript:
Uti in children
Introduction Pediatric UTIs often signal an underlying genitourinary tract abnormality Can lead to renal scarring with resultant hypertension and renal failure Difficult to diagnose because symptoms are non-specific in this age group and testing is often invasive
Pediatric UTIs: Epidemiology Prevalence Girls6.5-8% Boys2-3% Uncircumcised boys have a 5-20 X increase in UTIs vs circumcised boys Occurs in about 7% of children <2 who present with fever without a source
Epidemiology (continued) Incidence of vesicoureteral reflux (VUR) is 1% in children < 2 yoa. 50% of kids <1 yoa with UTI have VUR Early renal scarring is nearly twice as common in this age group. Incidence of scarring increases with each subsequent UTI Scarring occurs in 5-38% of febrile UTIs.
Figure 1 Prevalence of VUR by age. Plotted are the prevalences reported in 54 studies of urinary tract infections in children (references in Technical Report). Pediatrics 1999; 103:
Figure 2 Relationship between renal scarring and number of urinary tract infections.16 Pediatrics 1999; 103:
UTI: Classiffication Classification: Upper tract infection Acute pyelonephritis- fever, bacteriuria, systemic symptoms Lower tract infection Urethritis Cystitis Voiding symptoms, little or no fever, no systemic symptoms
Clinical Presentation Age and gender dependent months: Fever 2 mo.– 2 y/o: Fever (>38 C) Irritability Vomiting and Diarrhea Decrease appetite Between 1-2 y/o = crying on urination, foul smelling odor
Clinical Presentation 2 y/o – 6 y/o: Systemic symptoms Fever Flank or back pain Urgency, urinary incontinence, dysuria Suprapubic or abdominal pain Foul smelling odor > 6 y/o and adolescents: Same as above
Urethritis In female infants Part of a diaper dermatitis In adolescent girls and boys Presenting sign of STD In pre-school and school age girls Part of non-specific vulvovaginitis Generally environmental Bubble bath Nylon panties (also biker shorts, leotards, bathing suits) Poor hygiene (not wiping, wiping back to front) Overzealous hygiene Use of baby powder, perfumes
Symptoms of urethritis Dysuria Reluctance to void Perineal discomfort, erythema May be associated with vaginal irritation and erythema in girls In older boys, urethral discharge In adolescent girls associated with PID symptoms
Cystitis Afebrile usually Frequency Enuresis Dysuria Reluctance to void
Pyelonephritis Usually associated with fever and systemic signs 2° renal parenchymal inflammation Older children Flank pain or abdominal pain Younger children Fever, irritability, vomiting, poor feeding
Pyelonephritis - Significance EACH infection results in scar formation and reduced renal function After diabetes mellitus and collagen vascular disease, undetected renal disease and untreated childhood UTI may be responsible for: A large of portion of ESRD in adults A huge need for dialysis and transplantation
Pyelonephritis - Significance Untreated childhood UTI responsible for: Hypertension Impaired kidney function Complications of pregnancy
Causes and course of UTI
Risk Factors Age <1 year Female gender Uncircumcised males Constipation Voiding dysfunction Improper wiping Genitourinary abnormalities Vesicoureteral reflux Obstruction Colonization with virulent E. Coli
Signs and Symptoms – Children 2 months to 2 years Feverusually unexplained Vomiting and/or diarrhea Abdominal Pain Failure to thrive Malodorous urine Crying on urination
Signs and Symptoms – Children >2 Fever Vomiting and/or diarrhea Abdominal pain Malodorous urine Frequency and/or urgency Dysuria New incontinence
Summary Urinary tract infections are a common cause of fever without a source in children <2 and can lead to renal scarring, HTN or ESRD. Rapid treatment is essential. Symptoms are non-specific and thus a high level of suspicion is required Urine culture is required for diagnosis, and should be obtained by catheterization or SPA when child is ill or infection is suspected Treatment requires a 7-14d course of antibiotics Prophylactic abx are required after initial treatment All Children <2 require 2 imaging studies after initial UTI
References Committee on Quality Improvement, Subcommittee on Urinary Tract Infection. The diagnosis, treatment, and evaluation of the initial urinary tract infection in febrile infants and young children. Pediatrics 1999; 103: Layton, KL. Diagnosis and Management of Pediatric Urinary Tract Infections. Clinics in Family Practice 2003; 5: 2 Chon DH, Frank CL, Shortliffe LM. Pediatric Urinary Tract Infections. Pediatric Clinics of North America 2001; 48: Linderd KA, Shortliffe LM. Evaluation and management of pediatric urinary tract infections. Urologic Clinics of North America 1999; 26: McCollough M, Sharieff G. Marx: Rosens Emergency Medicine: Concepts and Clinical Practice, 5 th ed.2002; Acute Urinary Tract Infections Clinical Effective Committee. Evidence based clinical practice guideline for patients 6 years of age or less with a first time acute urinary tract infection. Cincinnati (OH): Childrens Hospital Medical Center 1999; 1-14
Patient groups Infants of 1 year Girls and boys Recurrent UTI (no abnormalities) Mild VUR (grade I and II) Options Long-term low dose antibiotics (Cochrane review) (Trimethoprim, Nitrofurantoin, Cotrimoxazole) Intermittent treatment of UTIs Time horizon 3 years of long-term antibiotics and follow-up to end stage renal disease NHS perspective long-term antibiotic treatment for preventing recurrent urinary tract infections (UTI) in children
Model Structure for UTI
The evidence Effectiveness Existing reviews (variable quality) Meta analysis, Multiple parameter synthesis Probabilistic trial based model Natural history Epidemiological studies Pooled trial baselines Registry studies Clinical judgement Quality of life Published studies Survey Costs Published studies Published unit costs and dosage (BNF, PSSRU, CIPFA)
Antenatal Period The most common cause is physiologic dilation. Metanephric urine production begins at 8 weeks, even before ureteral canalization is complete. Transient obstruction with hydronephrosis occurs.
Pathophysiology: Anatomic and functional processes interrupts the flow of urine. There is a rise in ureteral pressure causing stretching and dilation; if pressures continue to rise, leads to decline in renal blood flow and GFR. When significant obstruction is persistent, it affects nephrogenic tissue and results in varying degrees of cystic dysplasia and renal impairment.
Grading of Severity of Hydronephrosis
Most Common Causes in Neonates: Ureteropelvic Junction Obstruction Ureterovesical Junction Obstruction Posterior Urethral Valves Eagle-Barrett Syndrome (a.k.a. Prune Belly Syndrome) Vesicoureteral Reflux Ureterocele
Treatment for UPJ: Pyeloplasty
Urine Collection Clean Catch acceptable for toilet trained children (wearing underwear or pull-ups) Ensure cleansing with antiseptic towelette Catheterized specimen in diapered children Suprapubic bladder tap in <6 month old child is guaranteed sterile
Leukocyte Esterase Has to accumulate in urine Insufficient accumulation possible in small infants who void frequently Infants <3 months old may not have mature enough immune system to induce leukocytes in urine (beware neutropenia on CBC)
Nitrites By-products of E. coli and other lactose fermenters (glucose digestion) Insufficient accumulation possible in small infants who void frequently Insufficient accumulation possible in older child during the day and in older patient who has significant frequency If positive, highly suggestive of UTI (high specificity)
Microscopy >10 WBC/hpf on spun urine Bacteria on unspun urine are common unless catheterized specimen Gram stain is very helpful on spun urine Standard UA plus gram stain is enhanced UA
Urine Culture >100,000 cfu per mL on any culture >10,000 cfu per mL on cath specimen ANY bacterial growth on bladder tap (at least 1,000 cfu/mL)
Sensitivity and Specificity of Components of the UA Test Sensitivity % (Range) Specificity % (Range) Leukocyte esterase Nitrite Leukocyte esterase or nitrite positive Microscopy: white blood cells Microscopy: bacteria Leukocyte esterase or nitrite or Microscopy positive 83 (67.94) 53 (15-82) 93 (90-100) 73 (32-100) 81 (16-99) 99.8 (99.100) 78 (64-92) 98 (90-100) 72 (58-91) 81 (45-98) 83 (11-100) 70 (60-92)
Urine Cultures Held for 48 h but usually positive at 24 h for true UTI Requires another day for ID of organism May require another day for sensitivities If contains skin flora (S. epi., S. aureus or α-strep.) considered contamination secondary to poor specimen collection
Diagnosis Urinalysis Can be obtained by most convenient means if infant is not ill UTI CANNOT be diagnosed with UA alone If suspicious UA, the Urine Culture must be obtained via SPA or catheter specimen If UA does not suggest UTI, it is reasonable to follow child clinically
Table 1. Sensitivity and Specificity of Components of the Urinalysis, Alone and in Combination (References in Text) TestSensitivity % (Range) Specificity % (Range) Leukocyte esterase83 (67-94)78 (64-92) Nitrite53 (15-82)98 (90-100) Leukocyte esterase or nitrite positive 93 (90-100)72 (58-91) Microscopy: WBCs73 (32-100)81 (45-98) Microscopy: bacteria81 (16-99)83 (11-100) Leukocyte esterase or nitrite or microscopy positive 99.8 (99-100)70 (60-92) Pediatrics 1999; 103:
Diagnosis Urine Culture MUST be collected via catheter or SPA UTI CANNOT be diagnosed from a bag specimen Diagnosis of UTI requires Urine Culture LOE--Strong
Urine Collection: Suprapubic Aspirate Gold standard - >99% specificity Positive culture: any number of g- bacilli or >3000 CFU of g+ cocci
Treatment May initiate treatment either orally or parenterally Admit and use parenteral antibiotics if toxic, dehydrated or unable to take PO Choices: TMP/SMX Cephalosporin Amoxicillin (check local resistance)
Treatment--continued Improvement should be seen in hours If not having expected clinical response in 2 days, re-culture, consider changing antibiotics and do imaging studies Complete 7-14 day course of antibiotics 14 days should be given for those that were ill with clinical evidence of pyelonephritis
Prophylaxis After completion of initial antibiotics, children should be give a prophylactic dose of antibiotics until imaging studies complete Antibiotic should have high urinary excretion and low serum and fecal levels, thus minimizing the development of resistance.
Imaging Needs to be performed in ALL children <2 years old with initial UTI Need to perform at least 2 studies to image the upper and lower urinary tracts Acute imaging only necessary when appropriate clinical response is not achieved within 2 days
Ultrasound Should be done on all infants < 2yoa after their initial UTI Helps to detect hydronephrosis and ureteral dilation Has replaced IVP Need additional study to evalute VUR Is not as sensitive as renal cortical scintigraphy (DMSA) for detecting inflamation and scarring
Voiding Cystourethrography (VCUG) Used to identify and grade reflux Also evaluates the urethra and bladder for abnormalities – important for boys who may have posterior urethral valves and girls with voiding dysfunction Radionuclide cystography (RNC) – can also evaluate reflux, but does not delineate the lower tract anatomy well. Can be used for follow-up exams as has low ratiation dose
Renal Cortical Scintigraphy (DMSA) Very sensitive for evaluating acute inflammation from pyelonephritis as well as renal scarring Role in clinical management is still unclear
Treatment No short course therapy for small children No short course therapy for males Empiric therapy is directed at organisms and adjusted for age. Choose narrowest spectrum allowable considering host factors Adjust therapy when sensitivities available
IV antibiotics-Indications Any person of any age who appears clinically toxic or who has neutropenia Infants <1 mo until bacteremia, sepsis, & meningitis ruled out Children unable to tolerate oral antibiotics Immunocompromised patients
Antibiotic choice Neonates Ampicillin plus a second antibiotic (usually gentamycin or cefotaxime) to cover for GBS, Listeria, as well as gram negative organisms S. aureus and S. epi. can cause hematogenous pyelonephritis (in children instrumented :ET tube,central lines, etc) Vancomycin may be indicated for toxic patients or those unresponsive to initial therapy
Therapy Cefixime (Suprax) oral is as effective as parenteral ceftriaxone Cefpodoxime (Vantin) Bad tasting 10 mg/kg/day Fluoroquinolones are expensive and off label in pedi
Bacterial virulence Bacterial spectrum at the Ist Dept. of Pediatrics, in N=7850 (%) E. coli49 Enterococcus faecalis13 Proteus indol neg. 10 Klebsiella 7 Pseudomonas spp 7 Enterobacter spp 6 Proteus indol pos 3 Staphylococcus 3 Other 2
Sensitive host Age related factors Anatomy (short urethra, phymosis and adhesio cellularis preputii et labia minora, diaper) colonization Immunological susceptibility Mucosal barrier Inherited/acquired immunresponse Inherited/acquired Ex: IgA deficiency, P1 blood group
UTI Controversy #1: Antibiotic Prophylaxis Indications grade 1 VUR frequent UTI recurrences Problems Pt Rxd with antibiotic prophylaxis Increased infection with Proteus and Enterobacter pseudomonas and Candida increased in children with urogenital abnormalities Drug toxicity and sensitivities Antimicrobial choices (qhs better) TMP-SMX or Nitrofurantoin (GI disturbance) Keflex if < 3 months Quinolones in some circumstances
Posterior Urethral Valves Abnormal congenital mucosal folds that are thin membranes impeding bladder drainage. Most common obstructive urethral lesion in male newborns found at the distal prostatic urethra. Incidence is approxly 1 in 8,000 males. Approxly 50% have reflux. VCUG is the modality of choice.
Radiographic signs of PUV: distended prostatic urethra valve leaflets bladder and/or bladder neck hypertrophy diverticula narrow stream in the penile urethra incomplete emptying of the bladder
Treatment of PUV: Transurethral valve ablation, vesicostomy or upper tract diversion Urethral stricture is a common complication Fetal intervention carries a high risk with mortality rate of 43% ESRD, renal insufficiency and chronic renal failure are long-term consequences
30% of boys with posterior urethral valves whose symptoms present in infancy are at risk for progressive renal insufficiency.
PUV, 2 months, MCU
Mcu done for suspected PUV
9 months old child with dribbling of urine and difficulty in passing urine ?PUV MCU done Uroprophylaxis suggested Told by another Doc: not necessary Came with high grade fever after 1 month UTI
Vesicoureteral Reflux Retrograde propulsion of urine into the upper urinary tract during bladder contraction. Primary reflux is caused by attenuation of the trigone and the contiguous intravesical ureteral musculature. May be caused by the ectopic insertion of the ureter into the bladder wall resulting in a shorter intravesicular ureter, which acts as an incompetent valve during urination.
The ratio of the submucosal tunnel length to the ureteral diameter is the primary factor determining the effectiveness of the normal valve mechanism. It is normally 5:1, and in those with reflux it is 1.4:1. The intramural length increases from 0.5 cm at birth to 1.3 cm by 12 years of age. Duplication of the collecting system and ureteroceles should also be considered.
Some clinical facts about VUR: It is genetic. Occurs in about 30% of first-degree relatives. 1/3 of children with a urinary tract infection has reflux on VCUG. Primary reflux tends to resolve over time as intravesical segment elongates with growth.
Grading of Vesicoureteral Reflux
VUR Grading Grade I Grade II Grade III Grade IV Grade V Prognosis - 5% adults Scarring % Screening UTI
Prognosis: Resolves spontaneously before adolescence in: 90% of Gr. 1 reflux 80% of Gr. 2 50% of Gr. 3 10% of Gr. 4 0 in Grade 5 reflux Kidney is most susceptible to scarring in the first year of life and at the time of first upper tract infection. Scars less frequently develop after the age of 5. VUR and scarring lead to hypertension, progressive renal insufficiency and failure.
Treatment: Observation Medical treatment of infections Surgical treatment significant hydroureteronephrosis indicated if impossible to keep urine sterile and reflux persists acute pyelonephritis occurs evidence of increasing renal damage
MCU C/o Recurrent UTI
Endoscopic submucosal injection
Teflon Silicon Collagen
Bacterial virulence Virulence=factors that enable bacteria to invade the urinary tract Surface antigenes O: lipopolysacharides with endotoxin properties. Induces fever, local inflammation K, (capsular) antigene, prevents phagocytosis P fimbriae: bind to glycolipid receptors of the P blood group family A number of further factors not routinely checked