Urinary tract infections: to prophylaxis or not to prophylaxis?

The Intrarenal Reflux Diagnosed by Contrast-Enhanced Voiding Urosonography (ceVUS): A Reason for the Reclassification of Vesicoureteral Reflux and New Therapeutic Approach?

Vesicoureteral reflux (VUR) is defined as the urine backflow from the urinary bladder to the pyelo-caliceal system. In contrast, intrarenal reflux (IRR) is the backflow of urine from the renal calyces into the tubulointerstitial space. VURs, particularly those associated with IRR can result in reflux nephropathy when accompanied by urinary tract infection (UTI). The prevalence of IRR in patients with diagnosed VUR is 1-11% when using voiding cystourethrography (VCUG), while 11.9-61% when applying the contrast-enhanced voiding urosonography (ceVUS). The presence of IRR diagnosed by VCUG often correlates with parenchymal scars, when diagnosed by a 99mTc dimercaptosuccinic acid scan (DMSA scan), mostly in kidneys with high-grade VURs, and when diagnosed by ceVUS, it correlates with the wide spectrum of parenchymal changes on DMSA scan. The study performed by both ceVUS and DMSA scans showed IRRs associated with non-dilated VURs in 21% of all detected VURs. A significant difference regarding the existence of parenchymal damage was disclosed between the IRR-associated and IRR-non-associated VURs. A higher portion of parenchymal changes existed in the IRR-associated VURs, regardless of the VUR grade. That means that kidneys with IRR-associated VURs represent the high-risk group of VURs, which must be considered in the future classification of VURs. When using ceVUS, 62% of places where IRR was found were still unaffected by parenchymal changes. That was the basis for our recommendation of preventive use of long-term antibiotic prophylaxis until the IRR disappearance, regardless of the VUR grade. We propose a new classification of VURs using the ceVUS method, in which each VUR grade is subdivided based on the presence of an IRR.

Congenital anomalies of the kidney and urinary tract: antenatal diagnosis, management and counselling of families

Congenital anomalies of the kidney and urinary tract are collectively one of the most commonly diagnosed antenatal conditions. Clinicians have several tools available to diagnose anomalies, including imaging, biomarkers, family history and genetic studies. In certain cases, antenatal interventions such as vesico-amniotic shunting may be considered to improve postnatal outcomes.Congenital kidney anomalies detected antenatally can vary in clinical significance from almost no impact postnatally to significant morbidity and perinatal mortality. Prognosis broadly depends on kidney size, structure and amount of amniotic fluid, alongside genetics and family history, and progression on subsequent scans. It is important to counsel parents appropriately using a parent-focused and personalised approach. The use of a multidisciplinary team should always be considered.

Antibiotic Prophylaxis in Infants with Grade III, IV, or V Vesicoureteral Reflux

BACKGROUND

The efficacy of continuous antibiotic prophylaxis in preventing urinary tract infection (UTI) in infants with grade III, IV, or V vesicoureteral reflux is controversial.

METHODS

In this investigator-initiated, randomized, open-label trial performed in 39 European centers, we randomly assigned infants 1 to 5 months of age with grade III, IV, or V vesicoureteral reflux and no previous UTIs to receive continuous antibiotic prophylaxis (prophylaxis group) or no treatment (untreated group) for 24 months. The primary outcome was the occurrence of the first UTI during the trial period. Secondary outcomes included new kidney scarring and the estimated glomerular filtration rate (GFR) at 24 months.

RESULTS

A total of 292 participants underwent randomization (146 per group). Approximately 75% of the participants were male; the median age was 3 months, and 235 participants (80.5%) had grade IV or V vesicoureteral reflux. In the intention-to-treat analysis, a first UTI occurred in 31 participants (21.2%) in the prophylaxis group and in 52 participants (35.6%) in the untreated group (hazard ratio, 0.55; 95% confidence interval [CI], 0.35 to 0.86; P = 0.008); the number needed to treat for 2 years to prevent one UTI was 7 children (95% CI, 4 to 29). Among untreated participants, 64.4% had no UTI during the trial. The incidence of new kidney scars and the estimated GFR at 24 months did not differ substantially between the two groups. Pseudomonas species, other non-Escherichia coli organisms, and antibiotic resistance were more common in UTI isolates obtained from participants in the prophylaxis group than in isolates obtained from those in the untreated group. Serious adverse events were similar in the two groups.

CONCLUSIONS

In infants with grade III, IV, or V vesicoureteral reflux and no previous UTIs, continuous antibiotic prophylaxis provided a small but significant benefit in preventing a first UTI despite an increased occurrence of non-E. coli organisms and antibiotic resistance. (Funded by the Italian Ministry of Health and others; PREDICT ClinicalTrials.gov number, NCT02021006; EudraCT number, 2013-000309-21.).

Vesico-ureteric reflux in children and young people undergoing kidney transplantation

Vesico-ureteric reflux (VUR) into transplanted kidneys in children and young people is a common occurrence, found in 19 to 60% of those who had an anti-reflux procedure and up to 79% in the absence of such a procedure. While VUR is unlikely to be of concern without evidence of symptomatic urinary tract infections, less certainty exists regarding outcomes when the VUR is associated with urinary tract infection (UTI) and transplant pyelonephritis. Issues explored will include additional risk factors that might predispose to UTI, any effect of pyelonephritis on acute and long-term kidney allograft function and practical strategies that may reduce the prevalence of infection.

Molecular Study of Klebsiella Oxytoca Associated with Urinary Tract Infection in Children

Background:

There are scarce reports about the association of Klebsiella oxytoca (K. oxytoca) with urinary tract infection (UTI) in children. We aimed to evaluate the prevalence of fimA, mrkA, matB and pilQ adhesins genes and extended-spectrum beta-lactamase (ESBL) genes blaCTX-M, blaTEM and blaSHV by polymerase chain reaction (PCR) and to study biofilm formation and antibiotics resistance in K. oxytoca from children with UTI.

Methods:

This study was a retrospective cross-sectional study that included 120 children with UTI due to K. oxytoca. The bacteria were subjected to molecular detection of fimA, mrkA, matB and pilQ adhesins genes and ESBL genes blaCTX-M, blaTEM and blaSHV by PCR. Biofilm capacity was determined by the microtiter plate method.

Results:

The isolated K. oxytoca had positive ESBL activity in 45.8% of isolates. About 40% of isolates were biofilm producers. The frequency of adhesion genes among K. oxytoca was 91.7%, 83.3%, 48.3% and 37.5% for matB, pilQ, fimA and mrkA genes, respectively. For ESBL genes, the frequency was 38.3%, 36.7% and 33.3% for blaCTX-M, blaSHV and blaTEM genes, respectively. The commonest genes among ESBL isolates were blaCTX-M (83.6%), blaSHV (80%) then blaTEM gene (72.7%). A significant association (p=0.048) was detected between ESBL activity and biofilm formation by K. oxytoca.

Conclusion:

Present study highlights the emergence of K. oxytoca as a pathogen associated with UTI in children. There was a high prevalence of adhesin genes and ESBL genes among these isolates. The capacity of K. oxytoca to form biofilm was associated with ESBL production.

Retrospective 8-Year Study on the Antibiotic Resistance of Uropathogens in Children Hospitalised for Urinary Tract Infection in the Emilia-Romagna Region, Italy

The development and spread of antibiotic resistance is an increasingly important global public health problem, even in paediatric urinary tract infection (UTI). In light of the variability in the data, it is necessary to conduct surveillance studies to determine the prevalence of antibiotic resistance in specific geographical areas to optimize therapeutic management. In this observational, retrospective, multicentre study, the medical records of 1801 paediatric patients who were hospitalised for UTI between 1 January 2012, and 30 June 2020, in Emilia-Romagna, Italy, were analysed. Escherichia coli was the most frequently detected pathogen (75.6%), followed by Klebsiella pneumoniae (6.9%) and Pseudomonas aeruginosa (2.5%). Overall, 840 cases (46.7%) were due to antimicrobial-resistant uropathogens: 83 (4.7%) extended spectrum beta-lactamase (ESBL)-producing, 119 (6.7%) multidrug resistant (MDR) and 4 (0.2%) extensively drug resistant (XDR) bacteria. Empirical antibiotic therapy failed in 172 cases (9.6%). Having ESBL or MDR/XDR uropathogens, a history of recurrent UTI, antibiotic therapy in the preceding 30 days, and empirical treatment with amoxicillin or amoxicillin/clavulanate were significantly associated with treatment failure, whereas first-line therapy with third-generation cephalosporins was associated with protection against negative outcomes. In conclusion, the increase in the resistance of uropathogens to commonly used antibiotics requires continuous monitoring, and recommendations for antibiotic choice need updating. In our epidemiological context, amoxicillin/clavulanate no longer seems to be the appropriate first-line therapy for children hospitalised for UTI, whereas third-generation cephalosporins continue to be useful. To further limit the emergence of resistance, every effort to reduce and rationalise antibiotic consumption must be implemented.

Asian guidelines for urinary tract infection in children

The followings are the level of evidence (LE) and grade of recommendation (GR) on pediatric UTI in Asia. Classification according to the sites of infection (lower versus upper tract), the number of episode (first versus recurrent), the severity (simple versus severe), or the existence of complicating factor (uncomplicated versus complicated) is useful to differentiate children with UTI whether they are at risk of renal damage or not (LE: 2, GR: B). Diagnosis of UTI requires both urinalysis that suggests infection and positive urine culture (LE:3, GR B). For pre-toilet trained children, urine specimen for culture should be collected by urethral catheterization or suprapubic aspiration. For toilet trained children, midstream clean catch urine is reliable (LE: 3, GR: A). Urine culture is considered positive if it demonstrates growth of a single bacterium with the following colony counts: (1) any growth by suprapubic aspiration, (2) >5 × 104 CFU/ml by urethral catheterization, or (3) >105 CFU/ml by midstream clean catch (LE:3, GR: B). For children with febrile UTI, renal and bladder ultrasonography (RBUS) should be routinely performed as soon as possible (LE: 3, GR: C). RBUS should be followed up 6 months later in children with acute pyelonephritis and/or VUR (LE: 3, GR: C). Acute DMSA scan can be performed when severe acute pyelonephritis or congenital hypodysplasia is noted on RBUS or when the diagnosis of UTI is in doubt by the clinical presentation (LE: 3, GR: C). Late DMSA scan (>6 months after the febrile UTI) can be performed in children with severe acute pyelonephritis, high-grade VUR, recurrent febrile UTIs, or abnormal renal parenchyma on the follow-up RBUS (LE: 3, GR: C). Top-down or bottom-up approach for febrile UTI is suggested for the diagnosis of VUR. For top-down approach, VCUG should not be performed routinely for children after the first febrile UTI. VCUG is indicated when abnormalities are apparent on either RBUS or DMSA scan or both (LE: 2, GR: B). VCUG is also suggested after a repeat febrile UTI (LE:2, GR: B). Appropriate antibiotic should be given immediately after urine specimen for culture has been obtained (LE:2, GR: A). Initiating therapy with oral or parenteral antibiotics is equally efficacious for children (>3 months) with uncomplicated UTI (LE: 2: GR: A). The choice of empirical antibiotic agents is guided by the expected pathogen and the local resistance patterns (LE: 2, GR: A). For children with febrile UTI, the total course of antibiotic therapy should be 7-14 days (LE: 2, GR: B). Circumcision may, but not definitively, reduce the risk of febrile UTI in males and breakthrough febrile UTI in males with VUR. Circumcision should be offered to uncircumcised boys with febrile UTI and VUR in countries where circumcision is accepted by the general population (LE: 3, GR: B), while in countries where childhood circumcision is rarely performed, other measures for febrile UTI/VUR should be the preferred choice (LE: 4, GR: C). Bladder bowel dysfunction (BBD) is one of the key factors of progression of renal scarring (LE: 2). Early recognition and management of BBD are important in prevention of UTI recurrence (LE:2, GR: A). Antibiotic prophylaxis to prevent recurrent febrile UTI is indicated in children with moderate to high grade (III-V) VUR (LE: 1b, GR: A). Surgical intervention may be used to treat VUR in the setting of recurrent febrile UTI because it has been shown to decrease the incidence of recurrent pyelonephritis (LE: 2, GR: B).

Vesicoureteral reflux is it important to find?

Vesico-ureteral reflux (VUR) has long been recognized as associated with urinary tract infections (UTIs), renal scarring, and chronic kidney disease (CKD). The concept of "reflux nephropathy" was born, whereby the VUR was considered the culprit, predisposing to recurrent UTIs and providing a conduit whereby the infection could ascend to the kidneys resulting in scarring and destruction. The more severe grades of reflux were thought to place the young child at particular risk of CKD. The question being asked in this pro/con debate is whether VUR is indeed the culprit responsible for a significant proportion of children with CKD, a number of whom progress to end-stage kidney failure (ESKF), and is thus important to find and treat, or is it an innocent bystander associated with CKD and ESKF but not the cause. We believe the latter and will present convincing evidence supported by large scale prospective randomized controlled trials that VUR is not the ogre it was thought to be and is not important to find following a UTI (with some exceptions).

Short-term antibiotic exposure affected the type and resistance of uropathogens similar to long-term antibiotic prophylaxis in children hospitalised for urinary tract infections

AIM

We investigated the impact of any antibiotic exposure on unusual and resistant pathogens in children with a urinary tract infection (UTI).

METHODS

This was a retrospective cohort study of 695 children (54% female) hospitalised with 711 UTI episodes at Heraklion University Hospital, Greece, from January 2007 to December 2017. Three groups were studied: no previous antibiotic exposure, ongoing prophylaxis and short-term exposure to antibiotics in the last six months.

RESULTS

The median age at hospitalisation was 0.8 years (range 25 days to 15.9 years). Previous short-term exposure and prophylaxis were important determinants of non-Escherichia coli (E. coli) (OR 2.05, 95% CI 1.25-3.36, P = .0017 and OR 3.84, 95% CI 2.32-6.34, P < .0001, respectively) and extended-spectrum beta-lactamase-positive uropathogens (OR 2.43, 95% CI 1.36-4.32, P = .0025 and OR 2.63, 95% CI 1.31-5.33, P = .0070, respectively). Short-term antibiotics in the last 30 days or intravenous antibiotics were mostly associated with non-E. coli pathogens (OR 6.71 and OR 2.55, respectively). The most important determinants of E. coli resistance were short-term antibiotics for ampicillin (OR 2.58) and prophylaxis for cotrimoxazole (OR 2.64).

CONCLUSION

Recent short-term exposure to antibiotics and ongoing prophylaxis both had a significant impact on the type and resistance of uropathogens.

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.

Susceptibility of the Index Urinary Tract Infection to Prophylactic Antibiotics Is a Predictive Factor of Breakthrough Urinary Tract Infection in Children with Primary Vesicoureteral Reflux Receiving Continuous Antibiotic Prophylaxis

BACKGROUND

Few studies have reported on breakthrough urinary tract infection (UTI) associated with the susceptibility of index UTI to prophylactic antibiotics in children with primary vesicoureteral reflux (VUR) receiving continuous antibiotic prophylaxis (CAP). We assessed the impact of the susceptibility of index UTI to prophylactic antibiotics in breakthrough UTIs in children with primary VUR receiving CAP.

METHODS

We retrospectively reviewed the medical records of 81 children with primary VUR who were diagnosed after febrile or symptomatic UTI and subsequently received trimethoprim-sulfamethoxazole (TMP-SMX) as CAP between January 2010 and December 2013. We allocated children to a susceptible group or a resistant group based on the susceptibility of index UTI to TMP-SMX. We evaluated patient demographics and clinical outcomes after CAP according to the susceptibility of index UTI to TMP-SMX. Multivariate analysis was used to identify the predictive factors for breakthrough UTI.

RESULTS

Of the 81 children, 42 were classified into the susceptible group and 39 into the resistant group. The proportion of breakthrough UTI was 31.0% (13/42) in the susceptible group and 53.8% (21/39) in the resistant group (P = 0.037). Progression of renal scarring was observed in 0% of children in the susceptible group and 15% in the resistant group (P = 0.053). Multivariate analysis showed that TMP-SMX resistance and initial renal scarring were significant predictors of breakthrough UTI.

CONCLUSION

Susceptibility of index UTI to prophylactic antibiotics is a risk factor of breakthrough UTI and is associated with poor clinical outcomes in children with primary VUR receiving CAP.

Infección del tracto urinario en niños, una de las enfermedades infecciosas más prevalentes

La infección del tracto urinario (ITU) es una patología frecuente en la infancia y una de las causas más comunes de consulta en el servicio de urgencias pediátricas. Las manifestaciones clínicas pueden ser inespecíficas en los lactantes y niños pequeños; sin embargo, en los niños mayores la sintomatología es más específica, con la aparición de fiebre, dolor en flanco, puño percusión renal positiva y signos de irritación vesical como disuria, polaquiuria, tenesmo e incontinencia. El diagnóstico definitivo confirmatorio se realiza mediante cultivo de orina. El conocimiento sobre los factores de riesgo, junto con ciertas consideraciones de valoración clínica y epidemiologia, son esenciales para encaminar las estrategias preventivas de las infecciones urinarias.

Antimicrobial misuse in pediatric urinary tract infections: recurrences and renal scarring

Background

In children, urinary tract infection (UTI) is one of a common bacterial infection. This study was conducted to detect the uropathogen, antimicrobial susceptibility, pathogen associated with recurrences and renal scarring in children initially taken care from general practitioners and later presented to tertiary care.

Methods

Every inward UTI episode, culture and antimicrobial susceptibility was done while on past 6-month, history of infections and use of antimicrobials was collected using clinical records and demonstration of antimicrobials. Children with recurrent pyelonephritis was followed and in vitro bio film formation was assessed.

Results

Frequency of UTI was significantly high among infants (p = 0.03). Last 6-month, all (220) were exposed to antimicrobials. Cefixime was the commonly prescribed antimicrobial (p = 0.02). In current UTI episode, 64.5% (142/220) of children with UTI were consulted GPs’ prior to seek treatment from tertiary care pediatric unit (p = 0.02). While on follow up child who developed UTI, found urine culture isolates were significantly shifted from E. coli and K. pneumoniae to extended spectrum of beta-lactamase (ESBL) E. coli and K. pneumoniae. Out of 208 participants, 36 of them had re-current pyelonephritis (R-PN). Renal scarring (RS) was detected in 22 out of 70 patients with pyelonephritis following dimercaptosuccinic acid scan. Following each episodes of recurrent pyelonephritis 11% of new scar formation was detected (p = 0.02). Bio film forming E. coli and K. pneumoniae was significantly associated in patients with R-PN (p = 0.04).

Discussion

Medical care providers often prescribe antimicrobials without having an etiological diagnosis. While continuing exposure of third generation cephalosporin and carbapenem leads to development of ESBL and CRE microbes in great. The empiric uses of antimicrobials need to be stream lined with local epidemiology and antimicrobial susceptibility pattern. R-PN in childhood leads to RS. In great, bio film formation act as the focus for such recurrences.

Nuclear Medicine in Pediatric Nephro-Urology: An Overview

In the context of ante-natally diagnosed hydronephrosis, the vast majority of children with a dilated renal pelvis do not need any surgical treatment, as the dilatation resolves spontaneously with time. Slow drainage demonstrated at Tc-99m-mercaptoacetyltriglycine (MAG3) renography does not necessarily mean obstruction. Obstruction is defined as resistance to urinary outflow with urinary stasis at the level of the pelvic-ureteric junction (PUJ) which, if left untreated, will damage the kidney. Unfortunately this definition is retrospective and not clinically helpful. Therefore, the identification of the kidney at risk of losing function in an asymptomatic patient is a major research goal. In the context of renovascular hypertension a DMSA scan can be useful before and after revascularisation procedures (angioplasty or surgery) to assess for gain in kidney function. Renal calculi are increasingly frequent in children. Whilst the vast majority of patients with renal stones do not need functional imaging, DMSA scans with SPECT and a low dose limited CT can be very helpful in the case of complex renal calculi. Congenital renal anomalies such as duplex kidneys, horseshoe kidneys, crossed-fused kidneys and multi-cystic dysplastic kidneys greatly benefit from functional imaging to identify regional parenchymal function, thus directing further management. Positron emission tomography (PET) is being actively tested in genito-urinary malignancies. Encouraging initial reports suggest that F-18-fluorodeoxyglucose (FDG) PET is more sensitive than CT in the assessment of lymph nodal metastases in patients with genito-urinary sarcomas; an increased sensitivity in comparison to isotope bone scans for skeletal metastatic disease has also been reported. Further evaluation is necessary, especially with the promising advent of PET/MRI scanners. Nuclear Medicine in paediatric nephro-urology has stood the test of time and is opening up to new exciting developments.

The RIVUR trial: a factual interpretation of our data

Vesicoureteral reflux (VUR) increases the risk of urinary tract infection (UTI) and renal scarring. Many prospective studies have evaluated the role of antimicrobial prophylaxis in the prevention of recurrent UTI and renal scarring in children with VUR. Of these, the RIVUR trial was the largest, randomized, placebo-controlled, double blind, multicenter study, involving 607 children aged 2-72 months with grade I-IV VUR and a first or second symptomatic UTI. The median age of children in the RIVUR trial was 12 months, 92% were female, 91% were randomized after a first UTI, 86% had a febrile index UTI, and 71 (56%) of 126 toilet-trained children had bladder bowel dysfunction. Trimethoprim/sulfamethoxazole reduced the risk of UTI recurrences by 50% (hazard ratio 0.50; 95% confidence interval 0.34-0.74) as compared to placebo. No significant difference was seen in renal scarring between the two groups. However, this does not invalidate the role of prophylaxis in preventing renal scars because RIVUR and other recent prospective studies were not designed to address renal scarring as a primary study endpoint. In view of the RIVUR Trial and other studies that showed similar results, albeit in selected groups of patients, the debate on antimicrobial prophylaxis should shift from "no prophylaxis" to "selective prophylaxis" in children with VUR.

Evaluation and management of recurrent urinary tract infections in children: state of the art

Urinary tract infections (UTIs) represent an important cause of febrile illness in young children and can lead to renal scarring and kidney failure. However, diagnosis and treatment of recurrent UTI in children is an area of some controversy. Guidelines from the American Academy of Pediatrics, National Institute for Health and Clinical Excellence and European Society of Paediatric Radiology differ from each other in terms of the diagnostic algorithm to be followed. Treatment of vesicoureteral reflux and antibiotic prophylaxis for prevention of recurrent UTI are also areas of considerable debate. In this review, we collate and appraise recently published literature in order to formulate evidence-based guidance for the diagnosis and treatment of recurrent UTI in children.

Practical approach to screen vesicoureteral reflux after a first urinary tract infection

Introduction:

Vesicoureteral reflux (VUR) is a common pediatric urologic disorder. After the first urinary tract infection (UTI), imaging studies are recommended, starting with a renal ultrasound (RUS). Voiding cystourethrography (VCUG) and dimercaptosuccinic acid (DMSA) scan are the other main radiologic studies used to detect VUR. We evaluated the use of RUS as a screening method for VUR in children below 2 years of age, in order to avoid unnecessary VCUG.

Materials and Methods:

Medical records and imaging studies of infants (<2 years) who had their first UTI in a 6 year period were retrospectively reviewed. We evaluated the sensitivity, specificity, and negative predictive values of RUS and DMSA for diagnosing VUR.

Results:

Among 155 children (51% males) with their first UTI, 148 RUS were performed, 128 VCUG and 29 DMSA. VUR was detected in 21% patients; 14.5% low grade and 6.5% high grade. One hundred and twenty-one patients underwent both RUS and VCUG, 101 RUS were normal and 20 abnormal. Of the normal RUS 98% had no or low grade VUR. Among those with an abnormality on RUS 30% had high grade VUR (P < 0.001).

Conclusions:

After the first UTI in infants (<2 years) RUS is a good screening method for VUR. Among such shildren with a normal RUS, we do not recommend VCUG or DMSA. In our opinion, VCUG should be performed only in patients with abnormal findings in RUS or in recurrent UTI.

Long-term resistance trends of uropathogens and association with antimicrobial prophylaxis

BACKGROUND

The aim of this study was to identify long-term resistance trends of uropathogens and determine the effect of prophylaxis in a pediatric patient population.

MATERIALS AND METHODS

A total of 638 uropathogens were isolated from urine samples collected from children hospitalized for urinary tract infection during the 12-year study period (1997-2008) and analyzed.

RESULTS

The most frequent uropathogen identified was Escherichia coli (69 %), followed by Klebsiella spp. (9.7 %), Pseudomonas aeruginosa (6.7 %), Enterococcus spp. (5.6 %), and Proteus spp. (4.4 %). High resistance rates were observed for common agents used for empiric treatment, such as amoxicillin, cotrimoxazole, and ceftriaxone. Resistance increased over time for nitrofurantoin, ceftriaxone, and piperacilin-tazobactam (chi-square for trend p < 0.0002, p < 0.0034 and p < 0.014, respectively) and decreased for cefuroxime (p < 0.016) and gentamicin (p < 0.014). The use of prophylaxis was related to an increased proportion of non-E. coli pathogens (46.9 vs. 26.9 %; odds ratio 2.4, 95 % confidence interval 1.61-3.55; p < 0.0001), as well as to increased resistance of non-E. coli pathogens, and was a major risk factor associated with resistance to amoxiclav (p < 0.005), cotrimoxazole (p < 0.0001), cefuroxime (p < 0.0001), ceftriaxone (p < 0.0001), gentamicin (p < 0.0001), and nitrofurantoin (p < 0.0001).

CONCLUSIONS

Our findings point to considerable changes in the long-term resistance patterns of uropathogens and an association of prophylaxis with resistance. Our results suggest the need for continuous surveillance, re-evaluation of empiric regimens and further assessment of the role of prophylaxis in the treatment of urinary tract infection.

Place of ultrasonography in predicting vesicoureteral reflux in patients with mild renal scarring

OBJECTIVE

To evaluate the role of renal ultrasonography (USG) in predicting vesicoureteral reflux (VUR) in children with mild renal scarring determined by dimercaptosuccinic acid scintigraphy performed after attack of urinary tract infections (UTI).

METHODS

Dimercaptosuccinic acid scintigraphy, voiding cystourethrography (VCUG), and renal USG findings were evaluated retrospectively in children with UTI. Each kidney was evaluated as a separate renal unit (RU). RUs with severe scarring were excluded from the study. RUs having mild scarring with and without abnormal USG findings (group 1 and group 2, respectively) were compared in terms of the presence of VUR.

RESULTS

There were a total of 228 patients (70 men, mean age 47.06 ± 44.14 months) and 456 RUs. Of the 185 RUs with mild scarring, 55 had abnormal USG findings (group 1), whereas 130 had normal USG findings (group 2). The rates of VUR and severe VUR (≥grade 4) were higher in group 1 compared with group 2 (69% vs 43%, P = .001 and 35% vs 7% respectively, P <.001). The sensitivity, specificity, positive predictive value, negative predictive value, and odds ratio of USG findings in predicting VUR in RU with mild scarring were 68%, 80%, 38%, 93%, and 8.2, respectively.

CONCLUSION

Normal renal USG findings exclude a diagnosis of high-grade VUR to a large extend in children with UTI and mild renal scarring. Refraining from invasive VCUG might be a reasonable approach in these patients provided that no other predisposing factors for UTI and/or renal scarring present.

Ultrasound bladder wall thickness measurement in diagnosis of recurrent urinary tract infections and cystitis cystica in prepubertal girls

OBJECTIVE

To evaluate urinary bladder wall thickness (BWT) assessed by ultrasound as a diagnostic tool for cystitis cystica.

PATIENTS AND METHODS

This was a 9-year prospective study comprising 120 prepubertal girls. Sixty subjects of whom half underwent cystoscopy represented cases while the other 60 (those with a single urinary tract infection and healthy subjects) represented controls.

RESULTS

Based on receiver operating characteristics (ROC) analysis, BWT discriminated very well between cases and controls with area under the ROC curve close to 1.0. At the optimum cut-off defined at 3.9 mm, negative predictive value (NPV) was 100% leaving no probability of cystic cystitis with BWT <3.9 mm. Positive predictive value (PPV) was also very high (95.2%), indicating only around 4.82% probability of no cystic cystitis in patients with BWT values ≥3.9 mm. BWT could also distinguish between healthy subjects and those with a cured single urinary tract infection, although discriminatory properties were moderate (area under ROC 86.7%, PPV 78.8%, NPV 85.2%).

CONCLUSION

Ultrasound mucosal bladder wall measurement is a non-invasive, simple and quite reliable method in diagnosis of cystitis cystica in prepubertal girls with recurrent urinary tract infections.

Does hydronephrosis predict the presence of severe vesicoureteral reflux?

We hypothesized that, in patients with vesicoureteral reflux (VUR) grade IV or V, hydronephrosis will likely be found, if the patient has a full bladder during the renal ultrasound examination. Eight hundred thirty-seven patients were included in the study. Patients ranged in age from <1 month to 18.7 years, with a median age of 1.3 years. Five hundred sixty-nine were female and 268 were male. In this retrospective study, each patient underwent a voiding cystourethrogram (VCUG) and a renal ultrasound examination. The presence of hydronephrosis and bladder filling status in 131 renal units with VUR grade IV or V was evaluated. Sensitivity and specificity for hydronephrosis to detect the presence of VUR grades IV and V were 60 and 92 %, respectively. Positive predictive value and negative predictive value were 74 and 87 %, respectively. Odds ratios for the relationship between hydronephrosis and severe VUR was significant (p = 0.046).

CONCLUSION

In patients with grade IV or V VUR, hydronephrosis will be observed in the presence of a full bladder. Therefore, a renal ultrasound could be considered a screening test to decide on performing a VCUG.

Screening high-grade vesicoureteral reflux in young infants with a febrile urinary tract infection

BACKGROUND

The lack of good evidence for improved outcomes in children and young infants with febrile urinary tract infection (UTI) after aggressive treatment for vesicoureteral reflux (VUR) has raised doubts regarding the need for routine voiding cystourethrography (VCUG), and the appropriate imaging evaluation in these children remains controversial.

OBJECTIVES

This prospective study aimed to determine whether abnormalities found on acute dimercaptosuccinic acid (DMSA) scan and ultrasound (US) can help indicate the necessity of voiding cystourethrography (VCUG) in young infants.

METHODS

For 3.5 years, all infants younger than 3 months presenting with first febrile UTI were prospectively studied. All infants were hospitalized and investigated using US (<3 days after admission), DMSA scan (<5 days after admission), and VCUG (7-10 days after antibiotic treatment) after diagnosis. The association among findings of US, DMSA scan, and VCUG were evaluated.

RESULTS

From 220 infants, there were abnormal results in 136 (61.8%) US and in 111 (50.5%) DMSA scans. By US, ten infants (4.5%) with abscess or structural abnormalities other than VUR were diagnosed. High-grade (III-V) VUR was present in 39 patients (17.7%). The sensitivities for high-grade VUR of renal US alone (76.9%) or DMSA scan alone (82.1%) were not as good as that of the "OR rule" strategy, which had 92.3% sensitivity and 94.3% negative predictive value.

CONCLUSIONS

To screen high-grade VUR in young infants with febrile UTI, US and acute DMSA scan could be performed first. VCUG is only indicated when abnormalities are apparent on either US or DMSA scan or both.

Common childhood bacterial infections

Children with infectious diseases are commonly encountered in primary care settings. Identification of the subset of patients with bacterial infections is key in guiding the best possible management. Clinicians frequently care for children with infections of the upper respiratory tract, including acute otitis media, otitis externa, sinusitis, and pharyngitis. Conjunctivitis is not an uncommon reason for office visits. Bacterial pneumonia, urinary tract infections, and gastroenteritis are regularly seen. Over the last decade, a growing number of children have had infections of the skin and soft tissue, driven by the increased prevalence of infections caused by methicillin-resistant Staphylococcus aureus. The following review addresses the epidemiology and risk factors for specific infections and examines the clinical presentation and selection of appropriate diagnostic methods in such conditions. Methods to prevent these bacterial infections and recommendations for follow-up are suggested. Management of these infections requires that antimicrobial agents be used in a judicious manner in the outpatient setting. Such antibiotic therapy is recommended using both available clinical evidence and review of disease-specific treatment guidelines.

[Comparison of two protocols of febrile urinary tract infection management in children]

PURPOSE

To compare two first febrile urinary tract infection (UTI) management protocols with regards to the diagnosis of high-grade vesicoureteral reflux (VUR) and cost.

METHODS

This study compared two cohorts of children under 16 years of age, admitted for a first episode of febrile UTI. The first group (in 2005) was managed according to previous recommendations (IV treatment and cystography performed for all children under 3 years of age). The second group (in 2006) was managed according to age and procalcitonin level. High-grade VUR frequency, UTI recurrence, hospitalization rate, and cost were compared between the two cohorts.

RESULTS

A total of 225 children were included in 2005 and 116 in 2006. High-grade VUR was found in 6.2 and 9.5% of the patients in 2005 and 2006, respectively (P=0.274). There was no statistically significant difference in the UTI recurrence rate between the two cohorts (5.3% in 2005 and 8.6% in 2006; P=0.237). The mean cost of an episode of febrile UTI was not significantly different in 2005 and 2006 (€2235 in 2005, €2256 in 2006; P=0.902), but was lower for children older than 6 months in 2006 (€1292 versus €1882 in 2005; P=0.0042).

CONCLUSION

Our management protocol for a first febrile UTI episode in children based on procalcitonin levels seems to be suitable for the diagnosis of high-grade VUR. The hospitalization rate and the mean cost of management for children older than 6 months of age was significantly reduced in 2006. The management guidelines for a first occurrence of febrile UTI in children should be reconsidered.

Changes in bacterial resistance patterns in children with urinary tract infections on antimicrobial prophylaxis at University Hospital in Split

BACKGROUND

We assessed prevalence and resistance of uropathogens on antimicrobial agents (AA) from urine cultures (UC) in children hospitalized with urinary tract infections (UTI) at University Hospital in Split.

MATERIAL/METHODS

During the 7-year period, children hospitalized only once with UTI alone were compared to those repeatedly hospitalized, and who received long-term antimicrobial prophylaxis (LTAP), as well as those with associated anomalies of the urinary system (US).

RESULTS

E. coli was the most frequent isolate (67.7%) with resistance to ampicillin by 69.5%, amoxicillin/clavulonic acid by 3.5%, cephalexin by 6.6%, trimethoprim/sulfamethoxazole (TMP-SMX) by 27.5%, and nitrofurantoin by 0.4%. For other uropathogens, AA resistance rates were the following: 64.3%, 5.8%, 10.5%, 21.3%, and 7.9%. The high or increasing resistance to TMP-SMX is characterized by all uropathogens. Patients with anomalies of US showed a lower prevalence of E. coli and Enterococcus sp., but a higher prevalence of Pseudomonas sp., ESBL-producing E. coli and Klebsiella sp. than those without US anomalies. Repeatedly hospitalized patients showed a lower prevalence of E. coli, but a higher prevalence of Pseudomonas sp. and Klebsiella sp. than patients hospitalized only once. Both groups displayed significantly less resistance of Enterococcus sp. In patients receiving LTAP before hospitalization, E. coli was significantly more resistant to ampicillin, amoxicillin/clavulonic acid and TMP/SMX than in those without LTAP.

CONCLUSIONS

Based on our results, we recommend excluding ampicillin altogether, and reconsideration of further use of TMP-SMX, as well as use of nitrofurantoin, cephalexin and amoxicillin/clavulonic acid for LTAP in our region.

Characteristics of first urinary tract infection with fever in children: a prospective clinical and imaging study

BACKGROUND

Our objective is to provide the clinical characteristics, uropathogen frequencies, and antimicrobial resistance rates of first urinary tract infection (UTI) diagnosed in febrile Belgian children. The ability of noninvasive ultrasound to detect renal abnormalities and vesicoureteral reflux (VUR) in these patients was also assessed.

METHODS

We prospectively followed (median, 20 months) 209 children treated for first febrile UTI. Renal ultrasound (US) and voiding cystourethrography examinations were performed in all patients.

RESULTS

Among these children, 63% were females and 37% were males, and 75% of them had their first UTI before the age of 2 years. The most common causative agent was Escherichia coli (91% of cases) with high rate resistance to ampicillin (58%) and trimethoprim/sulfamethoxazole (38%). Of these children, 25% had evidence of VUR (15 boys and 38 girls). VUR was of low grade in 85% of cases. The overall performance of renal US as a diagnostic test to detect significant uropathies excluding low-grade VUR was excellent; the sensitivity attained 97% and the specificity 94%.

CONCLUSION

Girls represent 63% of cases with first UTI. For 91% of UTIs, Escherichia coli is held responsible with a high rate of resistance to ampicillin and trimethoprim/sulfamethoxazole. US is an excellent screening tool that allows avoidance of unjustified voiding cystourethrography studies.

Prevention of chronic kidney disease in spina bifida

OBJECTIVE

The prevalence of progressive chronic kidney disease (CKD) in children and adults with spina bifida is considerable, rising, and entirely preventable.

REMOVING THE CAUSE

PREVENTION OF SPINA BIFIDA: The best prevention of CKD in spina bifida is prevention of spina bifida itself through strategies that include folate supplementation, ideally before pregnancy.

THE CAUSE OF CKD

Dysfunctional bladder outlet causes febrile Urinary Tract Infections (UTI), even with clean intermittent catheterization (CIC), and subsequent renal scarring. The development of secondary vesicoureteric reflux (VUR) increases the risk of renal scarring and CKD.

FINDING THE IDEAL MARKER FOR MEASUREMENT OF RENAL FUNCTION IN SPINA BIFIDA

Creatinine-based methods are insensitive because of low muscle mass and underdeveloped musculature in the legs. Only Cystatin C-based eGFR can reliably assess global renal function in these patients. However, unilateral renal damage requires nuclear medicine scans, such as (99m)Tc DMSA. (VIDEO)URODYNAMICS STUDIES (UDS): Early treatment is recommended based on UDS with anticholinergics, CIC, and antibiotic prophylaxis when indicated. Overnight catheter drainage, Botox, and eventually augmentation cystoplasty are required for poorly compliant bladders. A continent child or one rendered continent following surgery is at a higher risk of renal damage.

CONCLUSION

A multidisciplinary approach is required to reduce the burden of CKD in patients with spina bifida. The right tools have to be utilized to monitor these patients, particularly if recurrent UTIs occur. Cystatin C eGFR is preferred for monitoring renal damage in these patients, and (99m)Tc DMSA scans have to be used to detect unilateral renal scarring.

Febrile urinary tract infections in 0- to 3-month-old infants: a prospective follow-up study

OBJECTIVE

To track the clinical evolution of febrile urinary tract infection (UTI) diagnosed in 0- to 3-month-old infants and characterize uropathogen frequencies, antimicrobial resistance rates, renal abnormalities, and differences in the sexes in this age group.

STUDY DESIGN

We observed prospectively 46 infants identified in a cohort of 209 children with first UTI diagnosed between July 2006 and July 2008 at the age of 0 to 3 months. Renal ultrasound scanning and voiding cystourethrography examinations were performed in all infants.

RESULTS

Infants < 3 months old represented 21% of all children with first UTI. Of these children, 26% were female and 74% were male. Escherichia coli was isolated in 88% of cases and had a high rate of resistance to ampicillin (71%) and to trimethoprim/sulfamethoxazole (47%); 21% of children had vesicoureteral reflux, which was of low-grade in 67% of cases, with spontaneous resolution before 2 years in all cases. In infants with normal ultrasound scanning results, a low-grade vesicoureteral reflux was subsequently found in 10% of cases.

CONCLUSION

Infants aged 0 to 3 months represent 21% of children treated for febrile UTI. Boys represent 74% of these cases. E coli is responsible for 88% of UTIs, with a high rate of resistance to antibiotics. When ultrasound scanning examination results are normal, the risk of missing a significant renal abnormality is expected to be extremely low.

Pediatric urinary tract infections: an analysis of hospitalizations, charges, and costs in the USA

This study evaluates the impact of pediatric urinary tract infection (UTI)s on the economy and inpatient healthcare utilization in the USA. A retrospective analysis of patient demographics and hospital economics was performed on children less than 18 years of age admitted with a UTI between 2000 and 2006 using the Healthcare Cost and Utilization Project Kids' Inpatient Database. Our results were stratified as follows. Hospital admissions-nearly 50,000 children/year were admitted with a UTI. Pediatric UTIs represented 1.8% of all pediatric hospitalizations. Seventy-three percent of patients were female and 40% were under 1 year of age. Payer information-from 2000 to 2006, pediatric insurance coverage shifted from the private sector to the public sector. Hospital cost-in 2000, estimated hospital costs for UTIs were $2,858 per hospitalization and rose to $3,838 by 2006. Mean hospital charges increased from $6,279 to $10,489 per stay. By 2006, aggregate hospital charges exceeded $520 million. Our results indicate that UTIs are among the most common pediatric admission diagnoses. Hospitalization is more common in females and younger children. Since 2000, hospital charges for UTIs increased disproportionately to hospital costs. Over time, more children hospitalized with a UTI depend on public agencies to cover healthcare expense. More efforts are needed to evaluate cost-effective strategies for evaluation and treatment of UTIs.

Evidence for and against urinary prophylaxis in vesicoureteral reflux

The role of antimicrobial prophylaxis in vesicoureteral reflux (VUR) has come under increasing scrutiny because of better analytical methods in the published literature, knowledge gained from VUR and renal scars diagnosed without preceding urinary tract infection (UTI), and better renal imaging modalities for diagnosing renal scars. A meta-analysis of the five recent randomized studies with a total of 809 patients with VUR diagnosed after UTI reveals a relative risk of UTI recurrence of 0.82 [95% confidence interval (CI) 0.62-1.08; p = 0.16) with prophylaxis. A meta-analysis of the four studies with a total of 662 patients with UTI with and without VUR evaluated for renal scarring reveals a relative risk of 1.04 (95% CI: 0.84-1.30; p = 0.69), with prophylaxis. However, these observations need to be interpreted with caution because of the limitations with these studies and their heterogeneity for meta-analysis, particularly for renal scarring. More research is needed to validate the role of prophylaxis in VUR diagnosed after UTI, and even more research is warranted to answer the questions regarding antimicrobial prophylaxis across the spectrum of VUR in different clinical settings.

Evaluating different imaging strategies in children after first febrile urinary tract infection

We conducted a retrospective multicenter review to estimate the prevalence of urological abnormalities in Chinese children with first febrile urinary tract infection (UTI) and to evaluate the selective imaging strategy recommended by the NICE guideline for detecting underlying abnormalities. Atypical UTI was defined as in the NICE UTI guideline. Overall, 576 boys and 244 girls aged below 24 months were reviewed. All underwent ultrasound (US) and micturating cystourethrogram (MCUG) and 612 underwent DMSA scans. US was abnormal in 73 (8.9%) and vesicoureteral reflux was shown in 195 patients (23.8%). A total of 126 patients were considered to have remediable urological abnormalities requiring additional surgical or medical interventions. The NICE guideline yielded excellent negative predictive values (NPV) of 100-94.4% in girls but 91% in boys. If all boys underwent US and DMSA and only those with atypical UTI or abnormal US or DMSA proceeded to MCUG, then the NPV increased to 95.2% and 97.4% for boys aged below and above 6 months, respectively. These revised strategies would substantially save invasive studies-DMSA and MCUG in 27 and 74% of girls aged below and above 6 months, respectively, or MCUG in 23 and 59% of boys aged below and above 6 months, respectively.

Outcome and management of isolated severe renal pelvis dilatation detected at postnatal screening

The aim of this study was to evaluate the incidence and outcome of isolated severe renal pelvis dilatation (RPD; APD>15<or=20 mm) in an unselected population of 2-month-old infants prospectively followed up for 12-14 months of life. Isolated severe renal pelvis dilatation was detected in 46 of the 11,801 (0.39%) infants screened. Nephro-urological investigations were initiated if RPD persisted, or if urinary tract infection (UTI) occurred during follow-up, and antibiotic therapy was administered only when UTI occurred. At follow-up, RPD persisted in 24 infants. Of these, 8 infants presented with vesico-ureteral reflux (VUR) of grade>or=3 and 16 with ureteropelvic junction obstruction (UPJO). Incidence of UTI was significantly higher (p<0.001) in infants of the study group than in infants of the control group (13.9 vs 2.5%). Our data suggest that isolated severe RPD may be a self-limiting condition and that antibiotic prophylaxis (AP) for the prevention of UTI should not be performed. Considering RDP resolution and the incidence of UTI during follow-up, investigations for uropathy in infants with isolated, severe RPD are justified in persistent cases, or when UTI occurs during follow-up. Careful clinical monitoring for signs of UTI and treatment of each episode of UTI may be sufficient and safe.

Is antibiotic prophylaxis effective in preventing urinary tract infections in patients with vesicoureteral reflux?

The main concern in the management of children with vesicoureteral reflux (VUR) is the prevention of urinary tract infections and avoidance of renal damage. Medical management has been recommended or preferentially suggested over surgery in all but a few select clinical situations. Prophylactic antibiotics are prescribed routinely in the management of young children with radiological evidence of VUR following an episode of acute pyelonephritis. Prophylaxis is generally maintained until the VUR resolves spontaneously or is corrected surgically. Although the administration of prophylactic antibiotics has been universal in children with VUR, some authors have reported that long-term antibiotic prophylaxis does not fully prevent urinary tract infections or scarring, that antibiotic-related adverse events are known to occur, and that the incidence of pyelonephritis does not increase in spite of prophylactic antibiotic cessation. Recently, four prospective, randomized, controlled trials of antibiotic prophylaxis for preventing pyelonephritis and renal scarring were reported and some placebo-controlled, double-blind prospective studies are ongoing. The goal of this review is to evaluate the treatment of VUR using antibiotic prophylaxis, and its advantages and disadvantages based on appropriate descriptions and studies in the literature.