Why is this important: 

• UTI is the most frequent bacterial infection in children < 2 years
• Clinical presentation is non-specific and urine sample cannot be obtained without invasive measures so dx is often delayed 

Who created these guidelines: 

• revision of practice parameters published in 1999
• committee included gen peds, epidemiology/informatics, peds ID, radiology, peds urology. 
• Guidelines were further reviewed by multiple subgroups within AAP and 5 external organizations in the US and Canada. 

Guideline objectives: 

• Focuses on the dx/management of initial UTI in febrile children < 2 years 
• studies suggest that incidence of UTI can be as high as 5% in < 2 yr with unexplained fever
• Neonates < 2 months were excluded 
• Children w/ obvious neuro or anatomic abnormality leading to recurrent UTI were excluded

Diagnosis: 

• Febrile infant w/ no other source of infection requiring abx 2/2 to toxic nature
  • obtain UA/Culture before abx
• Febrile infant w/ no other source of infection who are non-toxic: 
  • MD should assess likelihood of UTI
    • Low: clinical follow up without testing 
    • High (>2%): 2 options :
      • 1. Obtain UA/culture via cath or SPA 
      • 2. Obtain urine via bag, complete UA and if UA is suggestive of UTI obtain 2ndsample via cath or SPA. If negative, monitor clinically w/o abx
• To establish dx of UTI, MD should require both UA suggestive of infection (pyuria and bacteriuria) and 50K CFU of uropathogen cultured from non-bagged sample

What is a (+) UA

• UA: nitrates not good for children, LE has high SN, WBC threshold should be 5WBC/HPF
• Bacteriuria: the presence of bacteria correlates with 10^5 CFU on cx

Who should be tested ( Low risk vs. not):

• Females: age < 12 months; white race; fever > 39; duration > 2 days; no other ssx of infection
  • ≤ 1% chance of UTI ≤1 risk factor  
  • ≤2% chance ≤ 2 risk factors 
• Males: nonblack race; fever > 39; duration > 24 hours; no other ssx of infection
  • Uncircumcised: ≤2% chance only if they have no risk factors 
  • Circumcised:
    • ≤1% chance: ≤ 2 risk factors
    • ≤2% chance: ≤ 3 risk factors 

How should we test them? 

• Catheterization or suprapubic aspiration (SPA) 

• Dx of UTI cannot be made through urine cx collected in bag; these have an unacceptably high false positive rate and are valid only when negative. SP is only 63%

Treatment:

• Base choice of route of abx practically if toxic appearing or not tolerating PO, then tx parentally, otherwise PO 
• Base choice of agent on local biograms
• Adjust abx as needed based on culture SN results 
• Tx for 7-14 days (no difference found between 7,10, or 14 days but 1-3 days was inferior)

Follow up studies:

• Febrile infants with UTI should undergo RUS; if toxic recommended within first 2 days of dx, if well defer to later date. 
• Nuclear scans not recommended 
• VCUG are not recommended after first UTI unless RUS is abnormal