Urinary Tract Infection In Children

Dr. Alia Al-IbrahimConsultant Pediatric Nephrology

Clinical Assistant Professor

Contents:

1- Definition of UTI2- Etiology & pathogenesis3- Predisposing Factors4- Clinical presentations5-Investigations 6- Management7- Complications8- Special problems in UTI

Definition: Presence of bacteria in urine along with symptoms of infection.

Incidence:5% in Girls 1-2% in Boys

During the 1st year of life more common in boys due to higher risk of anomalies and after age of one more in girlsMales and females are equally affected in the neonatal period.

Etiology:Most common infecting pathogen : Escherichia Coli 80% of UTI.

Other pathogens: - Staphylococcus & Streptococcus Species - Enterobacteria ( Klebsiella, Proteus, pseudomonas) - Occasionally Candida albicans

UTI in Children

Route of infection: Neonate: HematogenousLater : Ascension of bacteria into the Urinary tract.

Development of UTI depend on: 1- Virulence of the invading bacteria.2- Susceptibility of the host; some families and structural abnormalities.

Predisposing factors:1- Conditions lead to urinary stasis : renal calculi, Obstructive Uropathy , VUR, & Voiding disorder.2- Immune deficiency3- Broad- spectrum antibiotics ( amoxicillin, cephalexin).4- constipation by organism moving from anus to urethra. 5- uncircumcised male

Clinical Presentation:1- Upper UTI (Pyelonephritis).2- Lower UTI ( Cystitis).The history & clinical coarse varies with the patient’s age & specific diagnosis.

0-2months: sepsis. Which also the presentation in premature infants along with poor feeding

2mon-2yrs: different presentation•Unexplained fever (low or high grade fever)•Irritability, poor oral intake, lower abdominal pain, vomiting, loose bowel movement (diarrhea).•Voiding symptoms of cystitis (frequency, urgency, hesitancy) •Crying on urination (burning urination)•Smelly urine•No fever or mild2yrs : Pyelonephritis( fever, irritability, poor appetite, abdominal flank pain back pain, voiding symptoms, tenderness in costovertebral angle or flank. cystitis : voiding symptoms ( urgency, frequency, hesitancy, dysuria, urinary incontinence) mild or no fever, Suprapubic or abdominal pain

>Pyuria, proteinuria & Hematuria may occur with or without UTI.>Nitrite concentrations & leukocyte estrase. Nitrite is positive in pseudomonas mostly , klebsiella or proteus infection. If nitrite is positive think of structural abnormality. Nitrite alone is not diagnostic, we need high WBC and suggestive signs and symptoms.Pyuria and bacteruria are not diagnostic.POSITIVE URINE CULTURE IS ESSENTIAL FOR DIAGNOSIS OF UTI.Urine culture: the most diagnostic if the patient is not receiving any antibiotics.-Suprapubic aspiration is common in kids <1 : any number of colonies is diagnostic.- IN-and- out catheterization: > 10³, if more than one year and if not possible do MSU. - Midstream clean-catch urine collection > 10,000- usually a single organism- 2 or more organism on the culture indicates contamination.

-Blood culture :neonate & infant-Pyelonephritis: CBC: neutrophlic leukocytosis high ESR C-reactive protein (ESR and C-reactive protein are non-specific and are elevated more in pyelonephritis than cystits . Distinction between upper & lower difficult in children

-Urine analysis & dipstick: High index of suspicion for UTI in febrile children particularly those with unexplained fever. Lasts for 2-3days;

> 5 WBC/ hpf in centrifuged fresh urine positive screening test.>Bacteria in cent. & non cent. Or phase contrast suggestible of UTI.

Management:

< 5 yrs:With systemic signs:1- Iv antibiotics (covering Ecoli) shift to oral after improvement for 10 -14 days. Start after taking the culture but don’t wait for the results, start them immediately. 2- US, renal cortical scintigraphy ( DMSA) , MCUG. If abnormal US, follow by DMSA

No systemic signs: 1- oral antibiotics for 7-10 days US, MCUG( if indicated)

> 5 yrs and Female: Female & Male with signs1- no signs : oral antibiotics Like < 5 yrs

Male (even if after 1 episode of UTI or female with recurrent UTI: 1- No signs: oral antibiotics2- US, MCUGWe do U/S to detect structural abnormality.DMSA is done after 2 months of the acute infection to detect scarring.MCUG is done to detect reflux.

COMPLICATIONS:1- VUR (it might be a complication of UTI, or primary causing UTI.2- Scarring. Might lead to HTN, if multiple it might lead to renal insufficiency.3- HTN4- Renal insufficiency.

Normal DMSA Acute Pyelonephritis

Scarring

VUR

Acute: no irregular borders and no scarring and no change in size

In chronic: irregular borders and scarring.

Special problems

1-Reurrent UTI:Two or more UTIs over a six –months period. There will be a period of remission followed by a recurrence of the infection.Causes: Inadequate treatment either due to compliance or improper prescription. unrecognized site of bacterial persistence such as small infected calculus or un recognized anatomic abnormality.

2-VUR: Abnormal backwash of urine into ureter or kidneyRadiological evaluation VCUG, Isotope cystogrm

3-Breakthrough UTI:Caused by:1- change in the resistance pattern of organisms colonizing the urethra.2- noncompliance.3- VUR4- Voiding dysfunction.( delay in urination or structural abnormality)

4-Voiding dysfunction:Detrusor instability & incomplete bladder emptying -Associated with daytime enuresis & constipation.- Increase risk of UTI & VUR.-RX: 1- Timed voiding 2- Treatment of constipation. 3- Prophylactic antibiotics. 4- Anticholinergic medications.

5-Asymptomatic bacteruria:No need for antibiotics to prevent resistance and recurrence would be with a more virulent organism, low risk of scarring.