Ulf Jodal

VARIABLE ADHERENCE TO NORMAL HUMAN URINARY-TRACT EPITHELIAL CELLS OF ESCHERICHIA COLI STRAINS ASSOCIATED WITH VARIOUS FORMS OF URINARY-TRACT INFECTION

The ability to become attached to normal epithelial cells from the urinary tract was much greater in Escherichia coli bacteria isolated from the urine of patients with acute symptomatic pyelonephritis or cystitis than in those isolated from the urine of patients with asymptomatic bacteriuria. Attachment of the bacteria could be prevented by incubation in urine containing antibodies against the strain tested. The ability to attach to uroepithelial cells might be a virulence factor for E. coli strains which cause symptomatic urinary-tract infection.

Micturition habits and incontinence in 7-year-old Swedish school entrants

The prevalence of incontinence in children has been extensively studied, but knowledge of other bladder symptoms is lacking in a healthy child population. The micturition habits of 3556 7-year-old school entrants were surveyed by a questionnaire supplemented by telephone interviews. One or more symptoms of a disturbed bladder function was reported in 26%, but most of these had moderate urgency as a sign of incomplete voluntary bladder control. Isolated bedwetting occurred in 2.8% of the girls and 7.0% of the boys, whereas nocturnal incontinence combined with daytime wetting was equally common in both sexes, 2.3% and 2.0% respectively. Diurnal incontinence was reported in 6.0% of the girls and 3.8% of the boys and was usually combined with other symptoms. The frequency of micturition in children without symptoms of bladder disturbance and with no previous urinary tract infection was 3–7 times per day.

THE NATURAL HISTORY OF BACTERIURIA IN CHILDHOOD

The highest figure for first-time UTI is found in infants below one year of age. These early infections are often pyelonephritic in character, but they are easily overlooked because symptoms are unspecific, high fever and failure to thrive being the most important. It has been shown that delay in start of treatment increases the risk of the child developing pyelonephritic scarring. There is reason to believe that undetected and therefore untreated attacks of pyelonephritis may be associated with renal scarring revealed later in life. This type of renal damage is associated with development of hypertension in about 10 per cent of children and it accounts for around 20 per cent of the children entered into dialysis and transplant programs. Prevention of such long-term problems would be of great value and pyelonephritic scarring is a potentially preventable disease. The majority of infants and young children with UTI are probably managed at the primary care level. It is therefore essential that general practitioners are well informed about the epidemiology of UTI in infancy and childhood and that adequate diagnostic facilities are provided. For example, suprapubic aspiration to obtain uncontaminated urine is a technique that may well be used in an outpatient setting, and dipslide cultures are accurate and inexpensive. In addition to young age, vesicoureteric reflux and repeated attacks of pyelonephritis are risk factors associated with development of renal scarring. Therefore, diagnostic imaging to detect children with anomalies within the urinary tract are especially important in the very young. Furthermore, long-term supervision should be provided and the parents advised to consult the doctor when there is suspicion of a new infection to avoid delay in treatment. There is no reason to perform general screening for bacteriuria in healthy infants. Although bacteriuria may be found in 1 to 2 per cent, asymptomatic children have a very high rate of spontaneous clearing of the bacteriuria and they seem to constitute a low-risk group. Instead, frequent culturing of urine from febrile infants would be much more important.

The Swedish Reflux Trial in Children: IV. Renal Damage

PURPOSE We compared the development of new renal damage in small children with dilating vesicoureteral reflux randomly allocated to antibiotic prophylaxis, endoscopic treatment or surveillance as the control group. MATERIALS AND METHODS Included in the study were 128 girls and 75 boys 1 to younger than 2 years with grade III-IV reflux. Voiding cystourethrography and dimercapto-succinic acid scintigraphy were done before randomization and after 2 years. Febrile urinary tract infections were recorded during followup. Data analysis was done by the intent to treat principle. RESULTS New renal damage in a previously unscarred area was seen in 13 girls and 2 boys. Eight of the 13 girls were on surveillance, 5 received endoscopic therapy and none were on prophylaxis (p = 0.0155). New damage was more common in children with than without febrile recurrence (11 of 49 or 22% vs 4 of 152 or 3%, p <0.0001). CONCLUSIONS In boys the rate of new renal damage was low. It was significantly higher in girls and most common in the control surveillance group. There was also a strong association between recurrent febrile UTIs and new renal damage in girls.

The Swedish Reflux Trial in Children: III. Urinary Tract Infection Pattern

PURPOSE We evaluated the difference in the febrile urinary tract infection rate in small children with dilating vesicoureteral reflux randomly allocated to 3 management alternatives, including antibiotic prophylaxis, endoscopic treatment or surveillance only as the control. MATERIALS AND METHODS At 23 centers a total of 203 children were included in the study, including 128 girls and 75 boys 1 to younger than 2 years. Vesicoureteral reflux grade III in 126 cases and IV in 77 was detected after a febrile urinary tract infection (194) after prenatal screening (9). Voiding cystourethrography and dimercapto-succinic acid scintigraphy were done before randomization and after 2 years. The febrile urinary tract infection rate was analyzed by the intent to treat principle. RESULTS We noted a total of 67 febrile recurrences in 42 girls and a total of 8 in 7 boys (p = 0.0001). There was a difference in the recurrence rate among treatment groups in girls with febrile infection in 8 of 43 (19%) on prophylaxis, 10 of 43 (23%) with endoscopic therapy and 24 of 42 (57%) on surveillance (p = 0.0002). In girls the recurrence rate was associated with persistent reflux after 2 years (p = 0.0095). However, reflux severity (grade III or IV) at study entry did not predict recurrence. CONCLUSIONS In this randomized, controlled trial there was a high rate of recurrent febrile urinary tract infection in girls older than 1 year with dilating vesicoureteral reflux at study entry but not in boys. Antibiotic prophylaxis and endoscopic treatment decreased the infection rate.

Incidence rate of first-time symptomatic urinary tract infection in children under 6 years of age

A retrospective population‐based study was performed to describe the incidence rate of first time symptomatic urinary tract infection in children under 6 y of age. A total number of 299 children was identified during the 20‐month study period in a population of 20 000 girls and 21 000 boys. The cumulative incidence rate during the first 6y of life was 6.6% for girls and 1.8% for boys. The annual incidence rate in girls of urinary tract infection/1000 at risk was between 9 and 14 for each of the six 1‐y age intervals. In girls, the proportion of febrile urinary tract infection was high during the infant year, while girls older than 2 y most often had non‐febrile infection. For infant boys, the incidence rate and the proportion of febrile urinary tract infection were comparable to that of girls, while after the first year of life urinary infection of any kind was rare, with an incidence rate of 1–2/1000 at risk.

LEVEL DIAGNOSIS OF SYMPTOMATIC URINARY TRACT INFECTIONS IN CHILDHOOD

ABSTRACT: Jodal, U., Lindberg, U. and Lincoln, K. (Department of Paediatrics and Institute of Medical Microbiology, University of Göteborg, Göteborg, Sweden). Level diagnosis of symptomatic urinary tract infections in childhood. Acta Paediatr Scand, 64:201, 1975.–As no method for localization of urinary tract infection has been shown to be absolutely reliable, six procedures have been carried out simultaneously in 25 girls with acute symptomatic infections and the reliability of each method assessed. While clinical diagnosis of pyelonephritis or cystitis correlated well with the overall results of the battery of tests, the reliability of individual tests varied. Highest reliability was obtained with CRP determinations followed by antibody titration, sedimentation rate, and renal concentrating capacity. In the bladder washout test only 8 of the 14 patients with pyelonephritis had findings clearly indicating high infection. Intermittent or inadequate discharge of bacteria from the renal parenchyma is suggested as the major source for this inaccuracy. In fact, half of the 42 final washout specimens from girls with acute pyelonephritis contained less than 1 000 bacteria per ml, indicating that low numbers of organisms in ureteric urine is common in childhood pyelonephritis.

Correlation of P Blood Group, Vesicoureteral Reflux, and Bacterial Attachment in Patients with Recurrent Pyelonephritis

Bacterial attachment to urinary-tract epithelium is important in the pathogenesis of urinary-tract infection. Most pyelonephritogenic Escherichia coli bind specifically to epithelial-cell receptors, which are glycolipids of the globoseries and also antigens in the P blood-group system. Among 36 girls with recurrent pyelonephritis who did not have vesicoureteral reflux, we found that attaching bacteria were common and the P1 blood-group phenotype was present in 97 per cent, as compared with 75 per cent of 84 age-matched children without urinary-tract infection (P less than 0.01). In 32 girls with recurrent pyelonephritis who had reflux, attaching bacteria were rare, and the frequency of the P1 phenotype was not significantly higher than in controls (82 per cent, P greater than 0.05). In the group of patients with the P1 phenotype, 68 per cent of the urinary bacterial isolates from those without reflux, but only 25 per cent of isolates from those with reflux, bound to globotetraosylceramide, as determined by a receptor-coating technique (P less than 0.001). Our data suggest that, in the absence of reflux, the P1 blood group contributes to susceptibility to recurrent pyelonephritis due to bacteria that bind to the glycolipid receptors of the globoseries. In the presence of reflux, uroepithelial attachment does not seem to confer an advantage to bacteria that infect the kidney.

Asymptomatic bacteriuria in schoolgirls VIII. Clinical course during a 3-year follow-up

A 3-year follow-up of 116 schoolgirls with asymptomatic bacteriuria, treated or untreated is reported. It is concluded that bacteria isolated from girls with asymptomatic bacteriuria do not commonly cause symptomatic pyelonephritis and that the risk of developing renal damage as a result of asymptomatic bacteriuria in a schoolgirl with a roentgenographically normal urinary tract seems to be small. It is also suggested that for the majority of these patients therapy is not necessary.

Primary and acquired renal scarring in boys and girls with urinary tract infection

OBJECTIVES To determine when pyelonephritic renal scarring was detected in children with urinary tract infection (UTI) and characterize those with primary and acquired scarring, respectively. STUDY DESIGN A population-based cohort of 1221 children (989 girls and 232 boys) with first recognized symptomatic UTI, aged 0 to 15 years, were diagnosed and followed up prospectively at a single childrens hospital; 652 had febrile UTI. Seven hundred fifty-three were evaluated by urography. Renal scarring was classified as primary or acquired, the latter without signs of scarring at the first investigation. To evaluate the frequency of recurrent UTI in those with acquired scarring, a comparison with group-matched children without scarring was performed. RESULTS A total of 74 children without obstruction had renal scarring (acquired in 40). Primary scarring was found in 18 of 21 (86%) of the boys and 16 of 53 (30%) of the girls (P <.001). The majority of boys with scarring had dilated reflux (67%) in contrast to girls (23%). Recurrent UTI was rare in boys, whereas girls with acquired scarring had significantly more febrile recurrences than girls without scarring. CONCLUSIONS Most boys had primary, probably congenital, reflux-associated renal damage, whereas most girls had acquired scarring related to recurrences of febrile UTI.