Urinary tract infection in outpatient febrile infants and children younger than 5 years of age

Work-up of Pediatric Urinary Tract Infection

Pediatric urinary tract infection (UTI) costs the health care system more than $180 million annually, and accounts for more than 1.5 million clinician visits per year. Accurate and timely diagnosis of these infections is important for determining appropriate treatment and preventing long-term complications such as renal scarring, hypertension, and end-stage renal disease. After the first 12 months, girls are more likely to be diagnosed with a UTI. About half of boys with UTI are diagnosed within the first 12 months of life. Diagnosis of UTI is made based on history and examination findings and confirmed by urine testing.

Multi-institutional experience with PIC cystography—incidence of occult vesicoureteral reflux in children with febrile urinary tract infections

OBJECTIVES

It has been reported that all children with febrile urinary tract infections (FUTIs) and normal voiding cystourethrogram (VCUG) findings show occult reflux (vesicoureteral reflux [VUR]) when examined by cystography performed with positioning of the instillation of contrast at the ureteral orifice (PIC cystography). In this study, we evaluated the reproducibility of this finding using a prospective multi-institutional collaborative examination to determine whether PIC-VUR is as common in such cases as previously shown.

METHODS

From March 2002 to October 2003, four institutions performed PIC cystography consecutively and prospectively in pediatric cases of FUTI (greater than 101 degrees F) who had not shown VUR by conventional VCUG. We correlated the ureteral orifice (UO) configuration and position with the status of PIC-VUR.

RESULTS

PIC cystography was performed in 39 children (31 girls and 8 boys; 75 FUTIs). We identified PIC-VUR in 32 (82%) of 39 children, involving 58 (74%) of 78 ureters. The likelihood of demonstrating PIC-VUR was increased 37-fold if the UO showed a patulous configuration and was increased 9-fold if the UO showed a lateral configuration. PIC-VUR was noted uniformly in UOs showing hydrodistension.

CONCLUSIONS

This multi-institutional registry showed that the incidence of PIC-VUR (82%) in children with FUTI and normal standard VCUG findings is similar to that previously reported. We consider that PIC-VUR likely accounts for the FUTIs.

Children with a febrile urinary tract infection and a negative radiologic workup: factors predictive of recurrence

OBJECTIVES

To determine the recurrence rate and risk factors for urinary tract infection (UTI) in children who present with a febrile UTI and have a negative radiologic evaluation. Febrile UTIs with no urinary tract abnormalities are a common cause of morbidity in children.

METHODS

We performed a retrospective review of all children referred to our medical center after a febrile UTI.

RESULTS

We reviewed 850 charts. Of 850 children, 78 had had a febrile UTI and normal ultrasound and voiding cystourography findings. Of the 78 children, 25 had had a recurrent UTI (3 boys and 22 girls). Forty-five percent of the girls with a febrile UTI developed a recurrent UTI and 14% of the boys had a recurrent UTI (P = 0.02). Three boys (two younger than 1 year of age) were uncircumcised and had one recurrent febrile UTI. Eleven (39%) of 28 girls who first presented at younger than 1 year of age and 7 (58%) of 12 girls who presented at 5 years of age or older had recurrent UTIs. The recurrence rate in the 2 to 5-year-old age group was 24% (4 of 17). Seven of the older girls exhibited symptoms of dysfunctional elimination syndrome.

CONCLUSIONS

In children with a febrile UTI and a negative radiologic evaluation, recurrence was more common in girls. Boys who were uncircumcised may be at an increased risk of infection during the first year of life. In girls, the age at the time of the first infection was not predictive of recurrence. Although dysfunctional voiding and elimination may contribute to recurrent febrile UTIs in young children, an association seems to be present in children 5 years old and older.

Urinary tract infections in children younger than 5 years of age: epidemiology, diagnosis, treatment, outcomes and prevention

Although the true incidence of urinary tract infections (UTIs) in children is difficult to estimate, they are one of the most common bacterial infections seen by clinicians who care for young children. Except for the first 8 to 12 weeks of life, when infection of the urinary tact may be secondary to a haematogenous source, UTI is believed to arise by the ascending route after entry of bacteria via the urethra. Enterobacteriaceae are the most common organisms isolated from uncomplicated UTI. Infection with Staphylococcus aureus is rare in children without in-dwelling catheters or other sources of infection, and coagulase-negative staphylococci and Candida spp. are associated with infections after instrumentation of the urinary tract. The diagnosis of UTI in young children is important as it is a marker for urinary tract abnormalities and, in the newborn, may be associated with bacteraemia. Early diagnosis is critical to preserve renal function of the growing kidney. A urine specimen for culture is necessary to document a UTI in a young child. Prior to culture, urinalysis may be useful to detect findings supporting a presumptive diagnosis of UTI. The goals of the management of UTI in a young child are: (i) prompt diagnosis of concomitant bacteraemia or meningitis, particularly in the infant; (ii) prevention of progressive renal disease by prompt eradication of the bacterial pathogen, identification of abnormalities of the urinary tract and prevention of recurrent infections; and (iii) resolution of the acute symptoms of the infection. Delay in initiation of the antibacterial therapy is associated with an increased risk of renal scarring. The initial choice of antibacterial therapy is based on the knowledge of the predominant pathogens in the patient's age group, antibacterial sensitivity patterns in the practice area, the clinical status of the patient and the opportunity for close follow-up. Imaging studies to detect congenital or acquired abnormalities are recommended following the first UTI in all children aged <6 years. Patients with significant urinary tract abnormalities and/or frequent symptomatic UTI may benefit from prophylactic antibacterials. The main long term consequence of UTI is renal scarring which may lead to hypertension and end-stage renal disease. Prevention of recurrent UTI focuses on detection, and correction if possible, of urinary tract abnormalities. Interventions that have been associated with a decrease in symptomatic UTI in children with a history of recurrent UTI include relief of constipation and voiding dysfunction.

[Antibiotic treatment of acute pyelonephritis in the child]

Antimicrobial therapy for pyelonephritis in children must quickly eradicate the bacterial infection and prevent scars in renal parenchyma. Escherichia coli (E Coli) is found in about 90% of cases of acute pyelonephritis in outpatients, 40% of E coli being ampicillin-resistant. The present effective antibiotics are: 3rd-generation cephalosporines, amoxicillin-clavulanic acid association, and aminoglycosides. In the literature therapeutical guides are divergent concerning the route of administration (oral or i.v.), mono or bitherapy, the duration of the treatment (usually for 10 days), and the need for hospitalisation. The criteria for choice are risk factors such as: very young age (< 6 months), fever with toxic symptoms, vomiting, dehydration, uropathy, and poor compliance. There are few long term studies which compare two, therapeutic regimens and no evaluation of the frequency of consequent chronic pyelonephritis in adult age has taken place. Recent data suggest that an oral sequential treatment may permit a shorter hospital stage. The trend is chiefly to do bona fide recommendations more than elaboration of a true consensus.

Management of pyelonephritis and upper urinary tract infections

The most frequent cause of upper urinary tract infection remains E. coli. Other organisms are found in complicated infections associated with diabetes mellitus, instrumentation, stone, and immunosuppression. The pathogenesis of acute pyelonephritis is reviewed herein, with an emphasis on the virulence factors responsible for its initiation, including urothelial adhesion by P-fimbriae of E. coli and other common factors including hemolysin and aerobactin. Renal damage does not always ensue following such infection. It is seen when toxic oxygen radicals are released during the ischemic episode and the respiratory burst of phagocytosis is marked and prolonged. These events occur when effective antibacterial treatment is delayed when the diagnosis is not made early or when socioeconomic factors prevent treatment. The scarring of chronic pyelonephritis leads to the loss of renal tissue and function and may progress to end-stage renal disease. With effective antibacterial therapy, the immune response by both T and B lymphocytes leads to antibodies that assist in bacterial eradication. Therapy must be both rapid and effective. In many instances, antibacterial agents may be used as outpatient therapy. If the Gram stain shows only gram-negative organisms and if the infection is community acquired, oral outpatient therapy with trimethoprim/sulfamethoxazole or a fluoroquinolone may suffice if the patient has no nausea. When the patient is septic, hospitalization and treatment with parenteral antibiotics are needed. Both ceftriaxone and gentamycin are cost-effective parenteral therapy because only once-daily dosing is needed. If gram-positive organisms are found, an enterococcus should be suspected, and a beta-lactam penicillin such as piperacillin or a third-generation cephalosporin such as ceftriaxone is indicated. If penicillin allergy exists, vancomycin should be used. If the patient does not improve rapidly, diagnostic studies including ultrasound and CT will assist in the diagnosis of obstruction, abscess, or emphysematous pyelonephritis. Most of these complications are now rapidly treated percutaneously, with surgical therapy following as needed. Complicated infections, such as those occurring in patients with anatomic abnormalities, stone, or immunosuppression, are often caused by organisms other than E. coli, and long-term antibacterial therapy often leads to fungal infections such as candidiasis. A recrudescence of tuberculosis is occurring, often with resistance to antituberculous drugs. The increased incidence has been associated with the immunosuppression of AIDS but is also occurring in intravenous drug users, perhaps because of poor nutrition but also owing to noncompliance with treatment. The symptoms of renal tuberculosis are usually limited to fever, frequency, urgency, and dysuria. Hematuria with sterile pyuria is the usual laboratory finding. The young urologist should remember this renal disease in the differential diagnosis of hematuria, because medical therapy can provide a cure.

Management of febrile children with urinary tract infections

This study of the management of children with fever and urinary tract infection (UTI) was conducted to identify factors associated with initial admission, outpatient treatment, and outpatient treatment failure. A retrospective chart review identified children 3 months to 16 years of age with an emergency department (ED) diagnosis of cystitis, pyelonephritis, or UTI, a positive urine culture, and an ED temperature of >38 degrees C. Sixty-nine patients (90% female) were studied; 19% were admitted initially. Age younger than 2 years was associated with admission (P < .001). Of those initially discharged, 63% received parenteral antibiotics (usually intramuscular ceftriaxone), followed by oral antibiotics; 9% failed outpatient treatment. Outpatient failure was associated with higher initial temperatures (median 40.1 degrees C v 39.2 degrees C, P=.03, Mann-Whitney U) but was unrelated to age, initial white blood cell count, or use of parenteral antibiotics. These results indicate that most children with fever and UTI do not require hospital admission; those with temperatures of > or = 40 degrees C are at increased risk for outpatient failure.