Practice Parameter: The Diagnosis, Treatment, and Evaluation of the Initial Urinary Tract Infection in Febrile Infants and Young Children
Authors:   Committee on Quality Improvement, Subcommittee on Urinary Tract Infection
Published: November 2017

Objective.
To formulate recommendations for health care professionals about the diagnosis, treatment, and evaluation of an initial urinary tract infection (UTI) in febrile infants and young children (ages 2 months to 2 years).

Design.
Comprehensive search and analysis of the medical literature, supplemented with consensus opinion of Subcommittee members.

Participants.
The American Academy of Pediatrics (AAP) Committee on Quality Improvement selected a Subcommittee composed of pediatricians with expertise in the fields of epidemiology and informatics, infectious diseases, nephrology, pediatric practice, radiology, and urology to draft the parameter. The Subcommittee, the AAP Committee on Quality Improvement, a review panel of office-based practitioners, and other groups within and outside the AAP reviewed and revised the parameter.

Methods.
The Subcommittee identified the population at highest risk of incurring renal damage from UTI—infants and young children with UTI and fever. A comprehensive bibliography on UTI in infants and young children was compiled. Literature was abstracted in a formal manner, and evidence tables were constructed. Decision analysis and cost-effectiveness analyses were performed to assess various strategies for diagnosis, treatment, and evaluation.

Technical Report.
The overall problem of managing UTI in children between 2 months and 2 years of age was conceptualized as an evidence model. The model depicts the relationship between the steps in diagnosis and management of UTI. The steps are divided into the following four phases: 1) recognizing the child at risk for UTI, 2) making the diagnosis of UTI, 3) short-term treatment of UTI, and 4) evaluation of the child with UTI for possible urinary tract abnormality.
Phase 1 represents the recognition of the child at risk for UTI. Age and other clinical features define a prevalence or a prior probability of UTI, determining whether the diagnosis should be pursued.
Phase 2 depicts the diagnosis of UTI. Alternative diagnostic strategies may be characterized by their cost, sensitivity, and specificity. The result of testing is the division of patients into groups according to a relatively higher or lower probability of having a UTI. The probability of UTI in each of these groups depends not only on the sensitivity and specificity of the test, but also on the prior probability of the UTI among the children being tested. In this way, the usefulness of a diagnostic test depends on the prior probability of UTI established in Phase 1.
Phase 3 represents the short-term treatment of UTI. Alternatives for treatment of UTI may be compared, based on their likelihood of clearing the initial UTI.
Phase 4 depicts the imaging evaluation of infants with the diagnosis of UTI to identify those with urinary tract abnormalities such as vesicoureteral reflux (VUR). Children with VUR are believed to be at risk for ongoing renal damage with subsequent infections, resulting in hypertension and renal failure. Prophylactic antibiotic therapy or surgical procedures such as ureteral reimplantation may prevent progressive renal damage. Therefore, identifying urinary abnormalities may offer the benefit of preventing hypertension and renal failure.
Because the consequences of detection and early management of UTI are affected by subsequent evaluation and long-term management and, likewise, long-term management of patients with UTI depends on how they are detected at the outset, the Subcommittee elected to analyze the entire process from detection of UTI to the evaluation for, and consequences of, urinary tract abnormalities. The full analysis of these data can be found in the technical report. History of the literature review along with evidence-tables and a comprehensive bibliography also are available in the report. This report is published in Pediatrics electronic pages and can be accessed at the following URL:http://www.pediatrics.org/cgi/content/full/103/4/e54.

Results.
Eleven recommendations are proposed for the diagnosis, management, and follow-up evaluation of infants and young children with unexplained fever who are later found to have a diagnosed UTI. Infants and young children are of particular concern because UTI in this age group (approximately 5%) may cause few recognizable signs or symptoms other than fever and has a higher potential for renal damage than in older children. Strategies for diagnosis and treatment depend on the clinician's assessment of the illness in the infant or young child. Diagnosis is based on the culture of a properly collected specimen of urine; urinalysis can only suggest the diagnosis. A sonogram should be performed on all infants and young children with fever and their first documented UTI; voiding cystourethrography or radionuclide cystography should be strongly considered.