Febrile urinary tract infection (UTI) is a common type of bacterial illness in children that may lead to acute renal parenchymal damage and permanent renal scarring. The objective of this study is to investigate the number of febrile UTIs associated with the risk of renal scarring in children.

This post hoc analysis included two multicenter studies, including a total of 345 children with a first febrile UTI without baseline renal abnormalities. The number of febrile UTIs was evaluated, and the primary outcome of the study was renal scarring defined by a reduced uptake of tracer associated with cortical thinning or loss of contours.

Of 345 children included in the study, 221 had vesicoureteral reflux, and 124 did not have vesicoureteral reflux. The incidence of renal scarring was 2.8% after 1 febrile UTI, 25% after 2 febrile UTIs, and 28.6% after 3 or more febrile UTIs. The odds ratio (OR) after a second febrile UTI was 11.8 times higher than after the first-time febrile UTI.

The research concluded that the risk of renal scarring in children with febrile UTIs was linearly associated with the number of febrile UTI incidents. For 3 or more incidents of febrile UTI, the risk of renal scarring was 28.6%.

Ref: https://jamanetwork.com/journals/jamapediatrics/fullarticle/2747329?resultClick=1