UTIs in children ( with controversies ) By Dr. Lindokuhle Mahlase
Epidemiology By age 7 years, 8 % of girls and 2 % of boys will have had a UTI. Most infections occur in the first 2 years of life ; boys during the first 6 months and girls thereafter.
Epidemiology USA Inpatient database identified that about 10 % of admissions for UTIs. Total hospital charges exceeded $ 520 million = R6.7 billion!
Clinical presentation Child : BOM & Frequency +/- Fever. Toddlers : Diarrhoea, vomiting, irritability, anorexia, FTT and fever. Neonates : Temperature instability, feeding intolerance, glucose instability and conjugated hyperbilirubinaemia.
Predisposing factors Anatomical abnormalities of the urinary tract Neurogenic/ Dysfunctional bladder Immunocompromised host Other (s): Constipation, Uncircumcised male, lack of breastfeeding & sexual intercourse
Facts about circ& UTI UTI is an ascending infection and circumcision reduces periurethral contamination with UTIforming organisms. Circumcision prevents UTI
Prophylactic Circ
UTI vs Circ Singh-Grewal et al concluded that the risk of complication outweighed the benefits in boys without UTI who undergo prophylactic circumcission.
Circumcision&UTIs in abnormal urinary tract Risk of UTI: Grade 3-5 VUR= 30% VUJ obstruction = 40 % PUJ obstruction = 14 % ( 1st year of life ) PUV= 50 %
No RCT published on circumcision reducing the risk of UTIs in boys with VUJ and PUJ obstruction. Circumcision and PUV : 1 large study = reduces risk by 83 % in PUV with circumcision vs control, but timing matters.
Diagnosis of UTI
Diagnosis of UTI Urine dipsticks Microscope Urine culture ( Catheter, SPU and Mid stream )
Urine dipsticks Leukocyte esterase: sensitivity 88%when compared with culture results False positive:- Fever, Kawasaki, vigorous exercise, SICC Negative : Asymptomatic pyuria
Urine dipsticks Nitrites: Conversion of nitrate to nitrites Req 4 hrs for conversion ( negative in frequent voiding) Helpful if positive
Microscope/Culture AAP def pyuria as > 3 WBC on HPF and > 50 000 CFU Question : Can we make a presumptive diagnosis of UTI base on urine dipsticks and microscope before the culture results.
Collected UA of 245 infants < 3 months with Bacteraemic UTI and 115 with negative urine culture. Results: + Urine Culture correlation with positive microscope and dipsticks.( 97.6 % sensitivity ) 93.9 % specificity
Specimen Collection Catheter SPU < 15 months Midstream once toilet trained
Compared 202 episodes of cystitis in women 18-49 years ( Paired MSU vs Cath specimens ) Results: 25 % of the patients who had a positive urine culture on their MSU specimen had no growth on their matched catheter specimen ( False positive )? Value of MSU
Consequences of UTI
Renal Scarring 99TC DMSA scan is the gold standard for assessing effect of UTI in the upper urinary tract. Scarring leads to reflux nephropathy: Hypertension Proteinuria Renal dysfunction ESRD
Risk of scarring after febrile UTI
Analysed 33 articles involving 4891 children with first febrile UTI. 57 % had abnormal DMSA scan ( 1.5 times more in children with VUR) 18 % had renal scars on DMSA at 5 months and 2 years repeat scan ( 2.6 times more likely with VUR)
Are scars assoc with VUR congenital or acquired?
34 infants with non obstructive VUR detected by prenatal sonar DMSA scan detected 50 % scars with grade III VUR and 75 % with IV-V VUR. Conclusion: Scarring was present despite the absence of prior infections.
Long-term consequences of UTI and scarring
Analysis of adults who had UTIs and VUR as children. 226 adults with VUR at mean age of 27 years Followed up for 10-41 years Presented with prior UTI at 5 years
Results: 84( 27%) had renal scarring at presentation 1 Boy developed a new scar at 7 years No new scars were noted in adults after a mean follow up of 19 years
Conclusion: New scars DO NOT develop in late childhood or adulthood despite persistence of VUR and recurrent UTIs.
Investigating initial UTI
Investigating UTI In 1999, the AAP recommended a renal US and VCU as standard diagnostic procedure. NICE 2007 - US only < for 6 months of age in uncomplicated UTI. APP 2011 ( initial febrile UTI ) US for 2-24months VCU should NOT be done as routine for first UTI VCU / MAG3 should be reserved for children with abnormal US
Treatment of UTI Simple cystitis ( amoxiclav ) for 10 days Uper urinary tract ( Ampicillin and Amik ) 10 days
Prevention of recurrence Prophylactic antibiotic for high grade VUR
RIVUR trial
Cranberry Juice Proanthocyanidins found in cranberry inhibit the adhesion of uropathogenic E. coli to uroepithelium.
Conclusion UTIs are more common than we think Urine dipsticks is good screening tool Exclude anatomical abnormalities on patients with established UTIs. Jury still out on antibiotic prophylaxis in children with VUR Consider in children with grossly dilated systems / PUV