title: Predictive factors associated with significant urinary tract abnormalities in infants with pyelonephritis.
abstract: BACKGROUND
  Major urinary tract abnormalities are detected in 20 to 40% of infants with acute pyelonephritis (APN). Early detection of structural defects is essential for protecting the kidneys from reinfection and subsequent scarring. The purpose of this study was to investigate whether any factors present during the acute phase of infection could predict the presence of existing significant urinary tract abnormalities in infants.
  
  
  METHODS
  A prospective study of 180 infants, aged 1 to 24 months, with APN was conducted. Blood and urine samples were collected. Renal ultrasound (US) was performed within 0 to 6 days from admission. Final diagnosis of the urinary tract anatomy was elucidated using the results of two or more radiologic imaging studies.
  
  
  RESULTS
  Risk factors for the presence of significant urinary tract abnormalities in infants were pathogens other than Escherichia coli in urine [relative risk (RR) 3.4, 95% confidence interval (CI) 2.2 to 5.3; P = 0.001], positive blood culture (RR 2.3, 95% CI 1.3 to 4.0; P = 0.039), young age (1 to 6 months) (RR 2.2, 95% CI 1.3 to 3.9; P = 0.004), lack of papG adhesin genes of E. coli in urine (RR 2.1, 95% CI 1.2 to 3.9; P = 0.016) and abnormal renal US (RR 2.0, 95% CI 1.2 to 3.4; P = 0.008).
  
  
  CONCLUSIONS
  Infants 1 to 6 months of age with APN caused by bacteria other than E. coli or by papG-negative E. coli strain, positive blood culture and abnormal renal US carry an increased risk for significant urinary tract abnormalities and need enforced follow-up.
authors: Hospital for Children and Adolescents, Helsinki, Finland. maria.jantunen@hus.fi
authors: M E
authors: ME
authors: Jantunen
authors: A
authors: A
authors: Siitonen
authors: M
authors: M
authors: Ala-Houhala
authors: P
authors: P
authors: Ashorn
authors: A
authors: A
authors: Föhr
authors: O
authors: O
authors: Koskimies
authors: S
authors: S
authors: Wikström
authors: H
authors: H
authors: Saxén
mesh_terms: D000208:Acute Disease; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011704:Pyelonephritis / Q000150:complications* / Q000382:microbiology*; D012307:Risk Factors; D014551:Urinary Tract / Q000002:abnormalities*