Treatment of Urinary Tract Infections with Significant Bacteriuria

Diagnostic Significance

The American Academy of Pediatrics recommends that a colony count of ≥50,000 CFU/mL of a single urinary pathogen is the appropriate threshold to consider bacteriuria "significant" and diagnostic of UTI in pediatric patients (2-24 months) 1, 2
The traditional threshold of >100,000 CFU/mL is not universally applicable to all populations, particularly pediatric patients 2
Organisms such as Lactobacillus species, coagulase-negative staphylococci, and Corynebacterium species are not considered clinically relevant urine isolates and should not be treated even if colony counts exceed this threshold 1

Oral or parenteral therapy is equally efficacious for initial treatment, and the route choice should be based on practical considerations, such as whether the patient can retain oral intake 1
Patients judged to be "toxic" or unable to retain oral medications should receive parenteral antimicrobials 1, 2

The American Academy of Pediatrics recommends selecting empiric therapy based on local antimicrobial sensitivity patterns, then adjusting according to susceptibility testing of the isolated uropathogen 1
Nitrofurantoin is a preferred first-line empiric option for uncomplicated UTI due to its high efficacy and ability to spare broader-spectrum agents 3
Fosfomycin tromethamine is also a first-line empiric option for uncomplicated UTI 3
Oral cephalosporins (cephalexin, cefixime, cefpodoxime, ceftibuten) are second-line options for uncomplicated UTI 3, 4

The American Academy of Pediatrics recommends treating UTIs for 7 to 14 days, with a strong recommendation based on evidence quality B 1, 2
For complicated UTIs, treatment duration should be closely related to management of the underlying abnormality 4, 5

The European Urology association recommends avoiding treatment of asymptomatic bacteriuria in most populations, as it may be harmful and lead to antibiotic resistance 6, 7
Exceptions include pregnant women and patients before urological procedures breaching the mucosa 6, 7

The American Academy of Pediatrics recommends always adjusting antimicrobial therapy according to sensitivity testing once available 1, 3
Initial empiric therapy should be modified based on the antibiogram to prevent overtreatment and reduce selection pressure for resistant organisms 1, 4

The primary objectives of treatment are to eliminate the acute infection, prevent complications including renal scarring, and reduce the likelihood of renal damage 1, 2