Observation of patients with vesicoureteral reflux off antibiotic prophylaxis: physician bias on patient selection and risk factors for recurrent febrile urinary tract infection

Antibiotic Prophylaxis for the Prevention of Urinary Tract Infections in Children: Guideline and Recommendations from the Emilia-Romagna Pediatric Urinary Tract Infections (UTI-Ped-ER) Study Group

Background: Urinary tract infection (UTI) represents one of the most common infectious diseases and a major cause of antibiotic prescription in children. To prevent recurrent infections and long-term complications, low-dose continuous antibiotic prophylaxis (CAP) has been used. However, the efficacy of CAP is controversial. The aim of this document was to develop updated guidelines on the efficacy and safety of CAP to prevent pediatric UTIs. Methods: A panel of experts on pediatric infectious diseases, pediatric nephrology, pediatric urology, and primary care was asked clinical questions concerning the role of CAP in preventing UTIs in children. Overall, 15 clinical questions were addressed, and the search strategy included accessing electronic databases and a manual search of gray literature published in the last 25 years. After data extraction and narrative synthesis of results, recommendations were developed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology. Results: The use of CAP is not recommended in children with a previous UTI, with recurrent UTIs, with vesicoureteral reflux (VUR) of any grade, with isolated hydronephrosis, and with neurogenic bladder. CAP is suggested in children with significant obstructive uropathies until surgical correction. Close surveillance based on early diagnosis of UTI episodes and prompt antibiotic therapy is proposed for conditions in which CAP is not recommended. Conclusions: Our systematic review shows that CAP plays a limited role in preventing recurrences of UTI in children and has no effect on its complications. On the other hand, the emergence of new antimicrobial resistances is a proven risk.

Contemporary Management of Urinary Tract Infections in Children

Purpose of Review

Urinary tract infection (UTI) in children is a major source of office visits and healthcare expenditure. Research into the diagnosis, treatment, and prophylaxis of UTI has evolved over the past 10 years. The development of new imaging techniques and UTI screening tools has improved our diagnostic accuracy tremendously. Identifying who to treat is imperative as the increase in multi-drug-resistant organisms has emphasized the need for antibiotic stewardship. This review covers the contemporary management of children with UTI and the data-driven paradigm shifts that have been implemented into clinical practice.

Recent Findings

With recent data illustrating the self-limiting nature and low prevalence of clinically significant vesicoureteral reflux (VUR), investigational imaging in children has become increasingly less frequent. Contrast-enhanced voiding urosonogram (CEVUS) has emerged as a useful diagnostic tool, as it can provide accurate detection of VUR without the need of radiation. The urinary and intestinal microbiomes are being investigated as potential therapeutic drug targets, as children with recurrent UTIs have significant alterations in bacterial proliferation. Use of adjunctive corticosteroids in children with pyelonephritis may decrease the risk of renal scarring and progressive renal insufficiency. The development of a vaccine against an antigen present on Escherichia coli may change the way we treat children with recurrent UTIs.

Summary

The American Academy of Pediatrics defines a UTI as the presence of at least 50,000 CFU/mL of a single uropathogen obtained by bladder catheterization with a dipstick urinalysis positive for leukocyte esterase (LE) or WBC present on urine microscopy. UTIs are more common in females, with uncircumcised males having the highest risk in the first year of life. E. coli is the most frequently cultured organism in UTI diagnoses and multi-drug-resistant strains are becoming more common. Diagnosis should be confirmed with an uncontaminated urine specimen, obtained from mid-stream collection, bladder catheterization, or suprapubic aspiration. Patients meeting criteria for imaging should undergo a renal and bladder ultrasound, with further investigational imaging based on results of ultrasound or clinical history. Continuous antibiotic prophylaxis is controversial; however, evidence shows patients with high-grade VUR and bladder and bowel dysfunction retain the most benefit. Open surgical repair of reflux is the gold standard for patients who fail medical management with endoscopic approaches available for select populations.

Guidelines for the medical management of pediatric vesicoureteral reflux

Urinary tract infection is a bacterial infection that commonly occurs in children. Vesicoureteral reflux is a major underlying precursor condition of urinary tract infection, and an important disorder in the field of pediatric urology. Vesicoureteral reflux is sometimes diagnosed postnatally in infants with fetal hydronephrosis diagnosed antenatally. Opinions vary regarding the diagnosis and treatment of vesicoureteral reflux, and diagnostic procedures remain debatable. In terms of medical interventions, options include either follow‐up observation in the hope of possible spontaneous resolution of vesicoureteral reflux with growth/development or provision of continuous antibiotic prophylaxis based on patient characteristics (age, presence/absence of febrile urinary tract infection, lower urinary tract dysfunction and constipation). Furthermore, there are various surgical procedures with different indications and rationales. These guidelines, formulated and issued by the Japanese Society of Pediatric Urology to assist medical management of pediatric vesicoureteral reflux, cover the following: epidemiology, clinical practice algorithm for vesicoureteral reflux, syndromes (dysuria with vesicoureteral reflux, and bladder and rectal dysfunction with vesicoureteral reflux), diagnosis, treatment (medical and surgical), secondary vesicoureteral reflux, long‐term prognosis and reflux nephropathy. They also provide the definition of bladder and bowel dysfunction, previously unavailable despite their close association with vesicoureteral reflux, and show the usefulness of diagnostic tests, continuous antibiotic prophylaxis and surgical intervention using site markings.

Antibiotic prophylaxis and reflux: critical review and assessment

The use of continuous antibiotic prophylaxis (CAP) was critical in the evolution of vesicoureteral reflux (VUR) from a condition in which surgery was the standard of treatment to its becoming a medically managed condition. The efficacy of antibiotic prophylaxis in the management of VUR has been challenged in recent years, and significant confusion exists as to its clinical value. This review summarizes the critical factors in the history, use, and investigation of antibiotic prophylaxis in VUR. This review provides suggestions for assessing the potential clinical utility of prophylaxis.

Predictive risk factors in childhood urinary tract infection, vesicoureteral reflux, and renal scarring management

Approaches to the management of children with urinary tract infection (UTI), vesicoureteral reflux (VUR), and renal scars have been challenged and have become controversial over the past decade. It is difficult to determine when, how, and which patients will benefit from the diagnosis and management of this condition. Therefore, the issues of diagnostic imaging, observation, follow-up, and intervention tend to be decided more on a case-by-case basis, rather than by using an algorithm. Over the past few years, there have been advances in the identification of risk factors that predispose patients with UTI to present with VUR, to develop recurrent UTIs and renal scars, to have deteriorating renal function, to show VUR improvement and/or spontaneous resolution, and to be candidates for and benefit from early surgical intervention.

Early discontinuation of antibiotic prophylaxis in patients with persistent primary vesicoureteral reflux initially detected during infancy: outcome analysis and risk factors for febrile urinary tract infection

PURPOSE

We retrospectively assessed the incidence of and risk factors for febrile urinary tract infection in children during active surveillance after early discontinuation of antibiotic prophylaxis.

MATERIALS AND METHODS

We retrospectively evaluated 9 females and 61 uncircumcised males diagnosed with primary vesicoureteral reflux before age 1 year who had persistent reflux on followup voiding cystourethrogram and were subsequently followed under active surveillance without continuous antibiotic prophylaxis. Patients with secondary vesicoureteral reflux or associated urological abnormality were excluded. Clinical outcomes, including incidence of febrile urinary tract infection and new scar formation, were evaluated. Risk factors for febrile urinary tract infection were also analyzed.

RESULTS

Mean age at stopping continuous antibiotic prophylaxis was 21 months, and mean followup was 61 months. During active surveillance 21 patients had febrile urinary tract infection, and the 5-year infection-free rate under active surveillance was 67.5%. One or 2 foci of minimal new scarring developed in 4 of 16 patients who underwent followup dimercapto-succinic acid scan after febrile urinary tract infection. On multivariate analysis dilated vesicoureteral reflux on followup voiding cystourethrogram was the only significant risk factor for febrile urinary tract infection.

CONCLUSIONS

This study revealed that about two-thirds of patients with persistent vesicoureteral reflux were free of febrile urinary tract infection during 5 years of active surveillance. Those with dilated vesicoureteral reflux on followup voiding cystourethrogram are at significantly greater risk for febrile urinary tract infection. Accordingly active surveillance, especially in patients with nondilated vesicoureteral reflux on followup voiding cystourethrogram, seems to be a safe option even in children who have not yet been toilet trained.

Ultrastructural and immunohistopathological evaluation of intravesical ureters via electron and light microscopy in children with vesicoureteral reflux

PURPOSE

We used immunohistochemical methods and transmission electron microscopy to investigate the cytokine profiles and ultrastructural changes in the ureterovesical junction of children with primary vesicoureteral reflux.

MATERIALS AND METHODS

A total of 39 distal intravesical ureters were obtained from 23 children who underwent ureteroneocystostomy for primary vesicoureteral reflux. Ureteral wall smooth muscle organization and transforming growth factor-β1, vascular endothelial growth factor and CD34 were evaluated immunohistochemically and compared to controls, which consisted of 10 age matched autopsy specimens. Ultrastructural evaluations and morphological descriptions were performed semiquantitatively and compared to the published data.

RESULTS

Of the patients 6 (26%) were male and 17 (74%) were female, and mean ± SD age was 73.2 ± 34.3 months (range 12 to 168). There was no correlation between reflux grade and age (p = 0.39). Smooth muscle disorganization score differed significantly between patients with intravesical ureters and controls (p = 0.01). Transforming growth factor-β1 levels were significantly higher (p = 0.001) and vascular endothelial growth factor levels and microvessel densities were significantly lower in the patients with reflux compared to controls (both p <0.001). Vascular endothelial growth factor, CD34 and transforming growth factor-β1 levels did not correlate with reflux grades (p = 0.84, p = 0.76 and p = 0.10, respectively). Urothelium, lamina propria and tunica adventitia appeared normal in the specimens for all grades of vesicoureteral reflux using transmission electron microscopy. Damage was observed in the muscular layers of the ureterovesical junction, especially in patients with grade IV or V reflux.

CONCLUSIONS

Primary refluxing ureters exhibit immunohistopathological abnormalities compared to normal ureters irrespective of reflux grade, and ultrastructural changes are especially severe in cases of high grade reflux. These abnormalities can hinder the normal ureteral valve mechanism, and may lead to reflux due to smooth muscle dysfunction and microvascular alterations.