This was a multicenter, randomized double blind, placebo controlled, non inferiority trial looking at children aged 2 months to 10 years with a diagnosis of urinary tract infection to see if the antibiotic course could be shortened from 10 days to 5 days in those patients who have clinically improved by day 5.
Children were prescribed amoxicillin/clavulanic acid, cefixime, cefdinir, cephalexin or trimethoprim-sulfamethoxazole and on day 6, after an in person visit were switched to placebo or continued the same antibiotic course.
A urine sample was collected on days 11-14 and treatment failure was defined as symptomatic urinary tract infection at or before this visit, asymptomatic bacteriuria, positive urine culture or gastrointestinal colonization with resistant organisms.
693 children were randomized in this trial. Children who received 5 days of antibiotics were more likely to have asymptomatic bacteriuria or a positive urine culture on days 11-14 (0.6 vs 4.2%). 28 children would need to be treated with a 10 day course to prevent one treatment failure with the 5 day course.
Bottom line: 10 days is still the ideal duration of treatment for a urinary tract infection, but the rate of failure of a 5 day course was low and the clinical significance of asymptomatic bacteriuria or a positive urine culture in an otherwise asymptomatic child is unknown.
References
Zaoutis et al. Short-Course Therapy for Urinary Tract Infections in Children The SCOUT Randomized Clinical Trial. JAMA pediatrics. published online June 26, 2023.
