Studies of urinary tract infections in infancy and childhood. X. Short or long-term treatment in girls with first or second-time urinary tract infections uncomplicated by obstructive urological abnormalities

Primary vesicoureteral reflux; what have we learnt from the recently published randomized, controlled trials?

In recent years, progress has been made on understanding the relationship between vesicoureteral reflux (VUR) and urinary tract infection (UTI). The findings on recent prospective, randomized, controlled studies have questioned the conventional VUR clinical significance and, therefore, have challenged the traditional diagnostic and therapeutic recommendations. These new studies have redefined the pathogenic role of vesicoureteral reflux in UTI as well as have disputed the routine use of urinary antibiotic prophylaxis to prevent UTI and renal damage in VUR patients. The time to overinvestigate and treat the vast majority of otherwise healthy children who have an uncomplicated UTI with long-term antibiotic prophylaxis seems to be over. Is there a role of severe VUR in the development of chronic renal disease and renal failure? New ideas are needed to answer these questions with the goal to avoid repeating past mistakes when therapeutic choices were based on expert opinions rather than facts.

Long-term antibiotics for preventing recurrent urinary tract infection in children

BACKGROUND

Urinary tract infection (UTI) is common in children. Symptoms include fever, lethargy, anorexia, and vomiting. UTI is caused by Escherichia coli in over 80% of cases and treatment is a course of antibiotics. Due to acute illness caused by UTI and the risk of pyelonephritis-induced permanent kidney damage, many children are given long-term (several months to 2 years) antibiotics aimed at preventing recurrence. This is the third update of a review first published in 2001 and updated in 2006, and 2011.

OBJECTIVES

To assess whether long-term antibiotic prophylaxis was more effective than placebo/no treatment in preventing recurrence of UTI in children, and if so which antibiotic in clinical use was the most effective. We also assessed the harms of long-term antibiotic treatment.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 30 July 2018 through contact with the Cochrane Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised comparisons of antibiotics with other antibiotics, placebo or no treatment to prevent recurrent UTI in children.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed and extracted information for the initial and previous updates. A random-effects model was used to estimate risk ratio (RR) and risk difference (RD) for recurrent UTI with 95% confidence intervals (CI).

MAIN RESULTS

In this update sixteen studies (2036 children randomised, 1977 analysed) were included. Seven studies (612 children) compared two or more types of antibiotics, six (1088 children) compared antibiotics with placebo or no treatment, one four-armed study compared circumcision with and without antibiotic treatment, one study compared dose of antibiotic, and one three-armed study compared two different antibiotics as well as no treatment. Of the sixteen included studies only one study was judged to be at low risk of bias for all domains, with the majority judged to be at unclear risk of bias due to very poorly reported methodology. The number of studies judged to be a low risk of bias was: selection bias (7); performance bias (4); detection bias (1); attrition bias (6); reporting bias (7); and other bias (2). The number of studies judged to be at high risk of bias was: selection bias (0); performance bias (5); detection bias (1); attrition bias (4); reporting bias (6); and other bias (1).Compared to placebo/no treatment, antibiotics lead to a modest decrease in the number of repeat symptomatic UTI in children; however the estimate from combining all studies was not certain and the confidence interval indicates low precision indicating that antibiotics may make little or no difference to risk of repeat infection (RR 0.75, 95% CI 0.28 to 1.98). When we combined only the data from studies with concealed treatment allocation, there was a similar reduction in risk of repeat symptomatic UTI in children taking antibiotics (RR 0.68) and we have greater certainty in this estimate because of the more robust study designs, the confidence interval is smaller and it does not include the point of no effect (95% CI 0.48 to 0.95). The estimated reduction in risk of repeat symptomatic UTI for children taking antibiotics was similar in children with vesicoureteric reflux (VUR) (RR 0.65, 95% CI 0.39 to 1.07) compared to those without VUR (RR 0.56, 95% CI 0.15 to 2.12) however there was considerable uncertainty due to imprecision from fewer events in the smaller group of children with VUR. There was no consistency in occurrence of adverse events, with one study having more events in the placebo group and a second study having more events in the antibiotics group. Three studies reported data for antibiotic resistance with the analysis estimating the risk of a UTI caused by a bacteria resistant to the prophylactic antibiotic being almost 2.5 times greater in children on antibiotics than for children on placebo or no treatment (RR 2.40, 95% CI 0.62 to 9.26). However the confidence interval is wide, showing imprecision and there may be little or no difference between the two groups.Eight studies involving 659 children compared one antibiotic with another but few studies compared the same combination for the same outcome so little data could be pooled. Two studies reported microbial resistance data and analysis showed that treatment with nitrofurantoin may lead to a lower risk of a UTI caused by a bacteria resistant to the treatment drug compared to children given trimethoprim-sulphamethoxazole as their prophylactic treatment (RR 0.54, 95% CI 0.31 to 0.92).

AUTHORS' CONCLUSIONS

Long-term antibiotics may reduce the risk of repeat symptomatic UTI in children who have had one or more previous UTIs but the benefit may be small and must be considered together with the increased risk of microbial resistance.

Antibiotics for the prevention of urinary tract infection in children: A systematic review of randomized controlled trials

OBJECTIVE

The objective was to evaluate the effectiveness of low-dose, long-term antibiotics for the prevention of symptomatic urinary tract infection (UTI) in children.

DESIGN

This was a systematic review of randomized controlled trials with a random effects model meta-analysis.

PARTICIPANTS

Five trials involving 463 children were performed.

RESULTS

Three trials (n = 392) evaluated the effectiveness of long treatment courses of antibiotics (2 to 6 months) for children with acute UTI to prevent subsequent, off-treatment infection. Only 2 trials (n = 71) evaluated the effectiveness of long-term, low-dose antibiotics to prevent on-treatment UTI. Very few of the children enrolled in the trials were boys, had abnormal renal tracts, or were infants. The trial quality was poor, with a lack of blinding, and unstated UTI definitions were almost universal. Long-term antibiotic administration reduced the risk of UTI with treatment (relative risk 0.31, 95% confidence limits 0.10 to 1.00), but there was significant heterogeneity (Q = 13.45, P <.01), and there was no sustained benefit once antibiotics had ceased (relative risk 0.79, 0.61 to 1.02).

CONCLUSIONS

Methodologic and applicability problems with published trials mean that there is considerable uncertainty about whether long-term, low-dose antibiotic administration prevents UTI in children. Well-designed, randomized, placebo-controlled trials are still required to evaluate this commonly used intervention.

Urinary infections in children 1985

Images

Three-day therapy with cephalexin for lower urinary tract infections in children

In a prospective study of children with an acute infection of the lower urinary tract, the effectiveness of a 3-day course of cephalexin, 25-50 mg/kg body weight and day was compared with that of a 10-day course of nitrofurantoin, 3-4 mg/kg/day. 19 children were allotted to treatment with cephalexin and 24 were treated with nitrofurantoin. The immediate cure rates were 90% and 96%, respectively. Two relapses were noted in the cephalexin group and 1 in the nitrofurantoin group. During a mean follow-up period of 7-8 months 2 of the cephalexin treated patients and 4 patients treated with nitrofurantoin had a reinfection. No side effects were noted in either of the treatment groups. The results suggest that treatment with cephalexin for 3 days is a reasonable alternative in children with an acute lower urinary tract infection when commonly used medications for one reason or another are less well tolerated.

Short-term treatment of lower urinary tract infections in children with trimethoprim/sulphadiazine

In a prospective study, 43 children between three months and 16 years of age and suffering from an acute infection of the lower urinary tract, were treated for either three or ten days with 4/16 mg trimethoprim/sulphadiazine/kgBW/day in two doses. Twenty-three were allotted to treatment for three days, whereas 20 were treated for ten days. Irrespective of the duration of therapy, the urine of all patients was sterile when urinary cultures were made three to seven days after the cessation of therapy. An early recurrence within the two months following the completion of treatment occurred in two children in each treatment group. In no case of recurrence was the organism resistant to trimethoprim/sulphadiazine. During a mean follow-up period of 11 months, 21.7% of the children treated for three days and 35% of those treated for ten days experienced a recurrence. The results suggest that children with an uncomplicated lower urinary tract infection can be successfully treated with a three-day course of trimethoprim/sulphadiazine in a conventional dosage.

Sulphonamides in the treatment of acute Escherichia coli infection of the urinary tract in women. Clinical and ecological effects of sulphasomidine and sulphalene

28 non-pregnant women were treated with conventional doses of sulphasomidine or sulphalene for acute urinary tract infections caused by Escherichia coli. Both preparations were found to be effective in simple cystitis infection with sulphonamide-sensitive organisms. Also, both were found to exert a selective pressure favouring sulphonamide-resistant E. coli in the faecal flora.

Frequency of E. coli K antigens in urinary-tract infections in children

The somatic (O) and casular (K) antigens of Escherichia coli from the urine of patients with acute pyelonephritis, acute cystitis, and asymptomatic bacteriuria, and in the faeces of healthy schoolchildren have been investigated. Typing antisera for sixteen capsular acidic polysaccharide K antigens were used, and five (numbers 1, 2, 3, 12, and 13) accounted for 70% of isolates from patients with acute pyelonephritis. These five K antigens were found to a lesser extent in the three other study groups. Thus, only a few K polysaccharides are associated with virulent properties of E. coli for the upper urinary tract. This finding is similar to the association of only some capsular types of pneumococci, meningococci, and Haemophilus influenzae with invasiveness. The identification of virulence markers for E. coli associated with upper-urinary-tract disease may permit more successful control with reference to preventive immunisation.

Esch. coli infections in childhood. Significance of bacterial virulence and immune defence

The Esch. coli harboured in the gut constitute a reservoir of potential pathogens in the infant and child. The conditions required for these intestinal inhabitants to cause infection are not well understood. The presence of virulence factors such as capsular antigens, especially K1, may be of significance for the ability of Esch. coli to cause neonatal meningitis. The capacity of certain Esch. coli to attach to epithelial cells of mucous membranes may be important for their infective powers in the urinary as well as the intestinal tract. Furthermore, the ability of certain Esch. coli to produce enterotoxins similar to that of V. cholerae is of importance for their capacity to provoke diarrhoea. The importance of the immune defence mechanisms for prevention of these Esch. coli infections is suggested, especially in the form of local immunity provided by secretory IgA antibodies. Such antibodies directed against Esch. coli O and K antigens as well as enterotoxins are present in large amounts in human milk and may be of considerable importance for protection against Esch. coli in the breast-fed baby. Breast feeding may be of special significance until the baby has built up its own local immune defence preventing the micro-organisms from attaching to and invading the intestinal mucous membranes. SIgA antibodies in urine may have a similar protective effect against urinary tract infections. The variable pictures of Esch. coli infections in childhood are striking, ranging from severe sepsis/meningitis or diarrhoea to "asymptomatic" bacteriuria. This variability is obviously closely connected with the presence of various virulence factors and the function of different components of the immune defence.

The periurethral aerobic flora in girls highly susceptible to urinary infections

After the age of 5 years, normal children have but few aerobic gram-negative rods periurethrally. This study examines whether there is an abnormal periurethral colonization in urinary tract infection-prone girls during infection-free intervals, indicating a defective local defence. In 13 girls with a history of recurrent infection, daily bacterial samples were obtained from the periurethral area and from urine. Sampling continued until an infection eventually occurred. Seven girls contracted a urinary tract infection within 3-30 days. All were heavy colonized with gram-negative rods, often several species, before infection appeared. Serotyping of E. coli confirmed that it was the colonizing strain which later invaded the bladder. The findings suggest a local defect in the antibacterial defence of infection-prone individuals and gives strong evidence for ascending infection. Six girls remained uninfected during an observation period of 9-123 days. They all had a normal periurethral flora. A reasonable hypothesis would be that the same factor counteracted colonization and infection. Since abnormal periurethral colonization was not a constant phenomenon the postulated defect may vary. This might explain the fact that urinary tract infections often appear in quick succession, often followed by long infection-free intervals.

Management of children with urinary tract infections: the Stanford experience

Two hundred seventy-eight female children with urinary tract infections have been evaluated at Stanford division of urology. All children were followed up for a period of not less than twelve months. Age of onset of infection, clinical presentation, and nature of infecting organisms were observed. The group consisted of 144 children without ureteral reflux and 134 children with ureteral reflux. Sixty-one of the female children with ureteral reflux had ureteral reimplantation, while 73 received medical treatment alone. A study of infection rates in each of the three groups of children indicated a similar infection rate, although those children with reflux experienced a higher incidence of clinical pyelonephritis. Correction of ureteral reflux did not alter the infection rate; however, infections after surgical correction were generally of a type usually associated with children without reflux. Twenty-nine children had urethral dilatation, and the infection rate prior to and following urethral dilatation indicated a similar rate of infection pre- and posturethral dilatation. One hundred nonrefluxing kidneys were observed radiologically: 97 were normal and 3 showed clubbing and scarring. Of 110 refluxing renal units observed, 62 were clubbed and scarred and 48 were normal. Following surgical correction of reflux, renal clubbing and scarring were not observed in previously normal renal units. Of those renal units found to be abnormal at time of surgery, 66 per cent showed progression of clubbing and scarring after surgical correction of reflux. It was observed that the greater the degree of reflux present, the higher the incidence of renal damage. This study suggests that children who experience recurrent urinary tract infections who do not have ureteral reflux are seldom at renal risk; similar children who do have ureteral reflux are at risk unless the infections are controlled or the reflux either disappears or is corrected surgically.

Duration of treatment for urinary tract infections in children

In a double-blind trial 45 children aged 6 months to 14 years with Escherichia coli infections of the urinary tract were given co-trimoxazole for two weeks and then allotted at random to one of two treatment groups for the remainder of six months; one continued with the active drug and the other with dummy tablets of identical appearance. Of the 24 children who took co-trimoxazole for two weeks and the 21 who took it for six months, 11 and 10, respectively, remained without further infections for at least a year. Over 90% of the reinfections occurred within five months of stopping the antibiotics, and the longer treatment did not cause any delay in their appearance. Thus probably a six-month course of treatment is no more likely to achieve a cure than a two-week course; nevertheless, no infection occurred during treatment, and there may be an advantage in continuing with antibiotics in small dosage.

Asymptomatic bacteriuria in schoolgirls. I. Clinical and laboratory findings

Among 116 schoolgirls with asymptomatic bacteriuria detected at urinary screening, renal parenchymal reduction was found in 10.3%, while reflux was found in 20.7%. Only 30% of the 116 patients had a history referable to earlier urinary tract infection and there were remarkably few girls with an increased sedimentation rate (4.4%), C-reactive protein (9.5%), pyuria (25.8%) or lowered concentrating capacity (3.4%) at the time of detection of their bacteriuria. No method was found efficient in predicting lesions on the pyelogram and urethrocystogram, but determination of renal concentrating capacity and C-reactive protein was of some value in predicting parenchymal reduction. The girls with pyelonephritic changes on the pyelogram had a mean renal concentrating capacity significantly lower than the girls without changes. The concentrating capacity of the girls with reflux but without renal scarring and those bacteriuric patients without radiologically demonstrated defects did not differ significantly from the age-related normal values.

The first urinary tract infection in the female infant. Prevalence, recurrence, and prognosis: a 10-year study in private practice

Eight hundred healthy female infants presenting for routine care were systematically screened for bacteriuria from early infancy to 2 years of age. The initial urinary tract infection was established in 29 infants, 3.6% of the series, at a median age of 9 months. Continued systematic screening of 25 of these 29 infants with bacteriuria to 6 years of age revealed recurrent infection in nine of them and the development of pyelonephritis in three. Recurrent episodes of infection occurred at close intervals of 2 weeks to 4 months in these nine infants and were clustered within an 18-month period. There were no recurrences after 3 years of age. Characteristically, both the initial and recurrent infections were asymptomatic. Lower urinary tract signs of infection, however, were evident to the "instructed parent," i.e., one instructed in the use of the urinary diary, a written log of the parents' observations of the infant's voiding habits. Pyelonephritis developed early in the children with recurrent infections; it was clinically inapparent and developed in infants with (initially) normal urinary tracts.

Sex differences in childhood urinary tract infection

Comparison of the clinical picture of nonobstructed urinary tract infection in boys and in girls over the age of 1 year revealed marked differences. The male infections were characterized by a high rate of `atypical' bacterial aetiology, macroscopical haematuria, and normal temperature, as compared to the female ones. The proportion of patients getting recurrent infections during long-term follow-up was the same in the two sexes. The number of recurrences was, however, higher in the girls than in the boys. Radiological changes similar to postinfectious scar formation were found in 20% of the boys at their apparent first infection.

Resistant urinary infections resulting from changes in resistance pattern of faecal flora induced by sulphonamide and hospital environment

The faecal flora was studied in eight children admitted to hospital for treatment of a first urinary infection with sulphonamides. The original, sulphonamide-sensitive Escherichia coli organisms were found to disappear, to be replaced by other E. coli serotypes that were almost invariably resistant to sulphonamides. Some of these serotypes carried R-factors for multiple antibiotic resistance.Possibly some urinary infections with antibiotic-resistant organisms may be due to faecal organisms whose resistance has been changed by previous antibiotic treatment. Hence it is important to study the effects of individual antibiotics on the faecal flora.