Urinary tract infections in children: Consensus and controversies

Abstract

and to the bloodstream (bacteremia). Bacterial infections are the most common cause of UTI, with E. coli being the most frequent (75-90%) of UTIs. Other bacterial sources include the following: Klebsiella species, Proteus species, Enterococcus species, Staphylococcus saprophyticus -especially among female adolescents and sexually active females, Streptococcus group B -especially among neonates, Pseudomonas aeruginosa, Fungi (Candida species) -especially after instrumentation of the urinary tract and rarely adenovirus. RISk FACToRS FoR InFeCTIon Host/Patient FactorsChildren younger than 5 years are predisposed to UTIs, because of periurethral colonization. These uropathogens are rare in children older than 5 years. Normal voiding results in complete washout of contaminating bacteria, pathogenic colonization of the urinary bladder is unlikely unless bladder defense mechanisms are impaired. Risk factors for UTI include anatomic anomaly (posterior urethral valves), voiding dysfunction (uninhibited detrusor contractions or neurogenic bladder), or constipation. Children who receive broad-spectrum antibiotics (e.g., amoxicillin, cephalexin) which alter gastrointestinal (GI) and periurethral flora are at an increased risk for UTI, because these drugs disturb the urinary tract's natural defense against colonization by pathogenic bacteria. The rate of UTIs in circumcised boys has been estimated at 0.2-0.4%, with the rate in uncircumcised boys being 5-20 times higher than in circumcised boys. In addition, some genes in humans may be associated with susceptibility to recurrent UTI. Also genetics may play a role in the progression of simple cystitis to pyelonephritis. Genetic testing may allow the identification of at-risk individuals and, therefore, prediction of genetic recurrences in their offspring. Non-secretors of P blood group antigen are also predisposed to UTI.