Doganis D et al. (2007) Does early treatment of urinary tract infection prevent renal damage? Pediatrics 120: e922–e928

Early treatment of pyelonephritis has been suggested to limit the extent of subsequent renal damage, although this effect has not been demonstrated in prospective clinical trials and remains controversial. In a recent study, Doganis and colleagues investigated the correlation of renal scintigraphy findings with the time interval between the onset of fever and the initiation of antibiotic therapy in 278 infants (aged ≤12 months) hospitalized with a first urinary tract infection.

Antibiotic therapy was initiated a median of 2 days after the onset of fever (range 1–8 days). Overall, renal inflammatory changes were seen in 57% of the infants, with bilateral defects observed in 13% of these. The prevalence of renal defects increased with increasing time between fever onset and treatment initiation; defects were seen in 41% of infants treated within the first day of infection, and 59%, 68% and 75% of the infants treated on days two, three, and four or later, respectively (P <0.0005 for trend). In total, 76 patients had an abnormal scan in the acute phase of infection and underwent renal scintigraphy a second time (at a median of 6.5 months after fever onset). In these infants the frequency of renal scarring did not differ between those treated in the first 24 hours, and those treated later (46% vs 54%), suggesting that while early antibiotic therapy can reduce the likelihood of renal involvement, it does not reduce the likelihood of developing renal scarring once acute pyelonephritis has occurred.