Urinary infection, reflux and renal scarring in females continuously followed for 13-38 years

This study describes the pattern of urinary tract infections (UTI) in 87 females prospectively followed for a median of 23 years from their first recognized symptomatic infection in childhood. At 16 years of age they were selected for follow-up into adulthood because of renal scarring (reflux nephropathy) in 45 and recurrent UTI in 42. The attack rate (number of urinary tract infections per individual per observation year) was highest during the 1st year of life (1.9), with a gradual decrease to the lowest rate (0.2) at age 11-15 years. A moderately increased attack rate (0.4), was seen in the late teens, extending through to the mid twenties. The proportion of infections having a pyelonephritic character decreased with age and number of infection episodes, but not in females with severe renal scarring. Pyelonephritic infections were correlated with vesicoureteric reflux, and renal scarring to low age at the index infection, total number of pyelonephritic episodes and reflux. Females with renal scarring continued to have a high proportion of pyelonephritic recurrences after 10 years of age, implying that they risk progressive renal disease and should be closely followed into adulthood.