Urinary tract infection in children (fever without focus, pyelonephritis, cystitis)

Paediatrics · Symptom or situation · updated 2026-11-08

BioMG follows French guidelines. Adapt it to the guidelines and the tests available where you practise.

Frequency: 7.0% of children under 2 years who consult for fever ^[1]

Unexplained fever or urinary symptoms, child over 1 month without severity signs

Urine microscopy and culture with susceptibility testing (midstream collection preferred; state the method of collection)if neededDipstick positive for leucocytes or nitrites ^[1,2]. A negative dipstick makes infection very unlikely and spares the urine culture (except in the newborn, neutropenia and sepsis) ^[1].
Urine collection bag only if the dipstick is clearly positive (leucocytes ++ or +++ and nitrites); otherwise midstream, urinary catheterisation or suprapubic aspiration.

Procalcitoninif neededFebrile infection for which oral cefixime is considered from the outset: the GPIP (French Group of Paediatric Infectious Pathology) reserves it for low-risk children, including a low PCT (with: over 3 months, no uropathy, no sepsis, good adherence) ^[1].
Serum creatinineif neededBefore treatment with amikacin, to be given after checking that renal function is normal ^[1]. A raised creatinine is also one of the NICE criteria for “atypical” infection, which justify an ultrasound during the episode ^[3].

Detailed explanation and international comparison (in French): read it in English (machine translation)

Urine microscopy and culture without a prior dipstick, except in the newborn under 1 month, neutropenia and sepsis: not advisable ^[1,2].
Routine urine microscopy and culture in every febrile child: it is reserved for high-risk children and those with urinary signs or unexplained fever for at least 48 hours ^[1].
Confirmatory urine culture collected by bag when the dipstick is not clearly positive: too many false positives (positive predictive value below 50%) ^[2].
CRP alone to distinguish pyelonephritis from cystitis: do not use it in this way ^[3].

Refer urgently to a paediatric department: hospital admission recommended before 3 months, in case of sepsis or known severe uropathy.
Samples taken in hospital before the antibiotic: urine microscopy and culture (without waiting for a dipstick before 1 month), blood cultures.

Detailed explanation and international comparison (in French): read it in English (machine translation)

Urine dipstick (looking for proteinuria), with blood pressure measurementif needednon-French guidelineChild with renal parenchymal lesions on imaging: weight, height, blood pressure and testing for proteinuria ^[3].
Recurrent infections or abnormal imaging: specialist paediatric opinion.

Detailed explanation and international comparison (in French): read it in English (machine translation)

Follow-up urine culture in a child who is asymptomatic again after a urinary tract infection: do not do it routinely ^[3].
Treatment or follow-up of asymptomatic bacteriuria: no antibiotic, no antibiotic prophylaxis, no follow-up on this ground alone ^[3].
Retrograde cystography or antibiotic prophylaxis after a first pyelonephritis: no reason to prescribe them, except in special situations ^[2].

Sources (7)