The Value of Level Diagnosis of Childhood Urinary Tract Infection in Predicting Renal Injury

Abstract

252 infants and children were followed for 2 years after their first urinary tract infection. Each symptomatic infection was determined by simple laboratory examinations as upper pyelonephritic or lower urinary tract infection. I.v. urography was done at the beginning of the follow-up and 2 years later; micturating cystourethrography was taken after the third infection at the latest. Urological abnormalities were found in 26 patients (10%), and 12 subjects (5%) developed renal scars during the study. Patients, who had their first upper urinary tract infection before the age of 12 months, numbered 93, and 19 of them had urological abnormalities and 10 scars. Two renal scars occurred among the 71 subjects with their first pyelonephritic infection after the age of 12 months. No renal injury was detected in the 88 infants and children with lower symptomatic urinary tract infection or asymptomatic bacteriuria. The determination of the level of the infection may be a useful aid in detecting the harmful scar-forming urinary tract infections. Infants with a pyelonephritic infection are at high risk, and in need of an early urological evaluation.

Infecção do trato urinário: em busca das evidências

“…Estima-se que cicatriz renal possa ocorrer em 5% a 15% das crianças após um episódio de ITU febril [5][6][7][8] . Como a cicatriz renal é um fator de risco para subseqüente hipertensão arterial, métodos para prevenir a ITU febril na infância estão em constante pesquisa.…”

“…A presença de cicatrizes renais tem sido documentada em 5% a 15% das crianças avaliadas após a primoinfecção urinária febril [5][6][7][8] .…”

Reflux nephropathy and hypertension

“…Primary VUR is common in young children (estimated incidence in the general population 0.1-1%, 1,2 in children presenting with UTI 12-50% 1,3 ), but disappears with time in the majority (80%). 4,5 A substantial number of subjects with VUR have established renal scars at diagnosis [6][7][8] with an increasing incidence with age (10% in preterm infants with VUR, 9 26% in children less than 8 years, 6 47% in children older than 8 years 6 and 94% in adults 5 ) or develop new scars at follow-up (5-58%). 7,8,10,11 There is a correlation between the extent of scarring and grade of VUR 12,13 although there is some disagreement on this issue.…”

“…15 It is considered that renal scarring mainly occurs in younger subjects (Ͻ5 years). 6,16 and that it is more likely to occur in the presence of urological abnormalities, 7 with recurrent UTI 10 particularly with upper tract involvement (eg, pyelonephritis), 7 and certain bacterial pathogens. 17 fore regular follow-up remains the only current means of recognising these subjects.…”

“…Factors that are of importance in the development of pyelonephritic scarring include youth, 7,122 reflux, 123 the character of UTI and the number of pyelonephritic episodes. 124 Prevention of the development of renal scars in VUR will, therefore, depend on early identification of patients at risk, ie, infants and children after the first UTI, siblings and offspring of affected individuals, as well as the aggressive treatment of UTI, 87,125 minimisation of intra-vesical pressure as well as education of parents, physicians and patients.…”