Incidence and outcome of symptomatic urinary tract infection in children

Incidence rates and trends of childhood urinary tract infections and antibiotic prescribing: registry-based study in general practices (2000 to 2020)

Background

To improve the management of childhood urinary tract infections, it is essential to understand the incidence rates, testing and treatment strategy.

Methods

A retrospective study using data from 45 to 104 general practices (2000 to 2020) in Flanders (Belgium). We calculated the incidence rates (per 1000 person-years) of cystitis, pyelonephritis, and lab-based urine tests per age (< 2, 2-4, 5-9 and 10-18 years)) and gender in children and performed an autoregressive time-series analysis and seasonality analysis. In children with UTI, we calculated the number of lab-based urine tests and antibiotic prescriptions per person-year and performed an autoregressive time-series analysis.

Results

There was a statistically significant increase in the number of UTI episodes from 2000 to 2020 in each age group (p < 0.05), except in boys 2-4 years. Overall, the change in incidence rate was low. In 2020, the incidence rates of cystitis were highest in girls 2-4 years old (40.3 /1000 person-years 95%CI 34.5-46.7) and lowest in boys 10-18 (2.6 /1000 person-years 95%CI 1.8-3.6) The incidence rates of pyelonephritis were highest in girls 2-4 years (5.5, 95%CI 3.5-8.1 /1000 person-years) and children < 2 years of age (boys: 5.4, 95%CI 3.1-8.8 and girls: 4.9, 95%CI 2.7-8.8 /1000 person-years). In children 2-10 years, there was an increase in number of lab-based urine tests per cystitis episode per year and a decrease in total number of electronic antibiotic prescriptions per cystitis episode per year, from 2000 to 2020. In children with cystitis < 10 years in 2020, 51% (95%CI 47-56%) received an electronic antibiotic prescription, of which the majority were broad-spectrum agents.

Conclusions

Over the last 21 years, there was a slight increase in the number of UTI episodes diagnosed in children in Flemish general practices, although the overall change was low. More targeted antibiotic therapy for cystitis in accordance with clinical guidelines is necessary to reduce the use of broad-spectrum agents in children below 10 years.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-022-01784-x.

Clinical Features for the Diagnosis of Pediatric Urinary Tract Infections: Systematic Review and Meta-Analysis

PURPOSE

Accurate diagnosis of urinary tract infection in children is essential because children left untreated can experience permanent renal injury. We aimed to assess the diagnostic value of clinical features of pediatric urinary tract infection.

METHODS

We performed a systematic review and meta-analysis of diagnostic test accuracy studies in ambulatory care. We searched the PubMed, Embase, Web of Science, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Register of Controlled Trials, Health Technology Assessment, and Database of Abstracts of Reviews of Effects databases from inception to January 27, 2020 for studies reporting 2 × 2 diagnostic accuracy data for clinical features compared with urine culture in children aged <18 years. For each clinical feature, we calculated likelihood ratios and posttest probabilities of urinary tract infection. To estimate summary parameters, we conducted a bivariate random effects meta-analysis and hierarchical summary receiver operating characteristic analysis.

RESULTS

A total of 35 studies (N = 78,427 patients) of moderate to high quality were included, providing information on 58 clinical features and 6 prediction rules. Only circumcision (negative likelihood ratio [LR-] 0.24; 95% CI, 0.08-0.72; n = 8), stridor (LR- 0.20; 95% CI, 0.05-0.81; n = 1), and diaper rash (LR- 0.13; 95% CI, 0.02-0.92; n = 1) were useful for ruling out urinary tract infection. Body temperature or fever duration showed limited diagnostic value (area under the receiver operating characteristic curve 0.61; 95% CI, 0.47-0.73; n = 16). The Diagnosis of Urinary Tract Infection in Young Children score, Gorelick Scale score, and UTIcalc (https://uticalc.pitt.edu) might be useful to identify children eligible for urine sampling.

CONCLUSIONS

Few clinical signs and symptoms are useful for diagnosing or ruling out urinary tract infection in children. Clinical prediction rules might be more accurate; however, they should be validated externally. Physicians should not restrict urine sampling to children with unexplained fever or other features suggestive of urinary tract infection.

The Diagnosis of Urinary Tract infection in Young children (DUTY): a diagnostic prospective observational study to derive and validate a clinical algorithm for the diagnosis of urinary tract infection in children presenting to primary care with an acute illness

BACKGROUND

It is not clear which young children presenting acutely unwell to primary care should be investigated for urinary tract infection (UTI) and whether or not dipstick testing should be used to inform antibiotic treatment.

OBJECTIVES

To develop algorithms to accurately identify pre-school children in whom urine should be obtained; assess whether or not dipstick urinalysis provides additional diagnostic information; and model algorithm cost-effectiveness.

DESIGN

Multicentre, prospective diagnostic cohort study.

SETTING AND PARTICIPANTS

Children < 5 years old presenting to primary care with an acute illness and/or new urinary symptoms.

METHODS

One hundred and seven clinical characteristics (index tests) were recorded from the child's past medical history, symptoms, physical examination signs and urine dipstick test. Prior to dipstick results clinician opinion of UTI likelihood ('clinical diagnosis') and urine sampling and treatment intentions ('clinical judgement') were recorded. All index tests were measured blind to the reference standard, defined as a pure or predominant uropathogen cultured at ≥ 10(5) colony-forming units (CFU)/ml in a single research laboratory. Urine was collected by clean catch (preferred) or nappy pad. Index tests were sequentially evaluated in two groups, stratified by urine collection method: parent-reported symptoms with clinician-reported signs, and urine dipstick results. Diagnostic accuracy was quantified using area under receiver operating characteristic curve (AUROC) with 95% confidence interval (CI) and bootstrap-validated AUROC, and compared with the 'clinician diagnosis' AUROC. Decision-analytic models were used to identify optimal urine sampling strategy compared with 'clinical judgement'.

RESULTS

A total of 7163 children were recruited, of whom 50% were female and 49% were < 2 years old. Culture results were available for 5017 (70%); 2740 children provided clean-catch samples, 94% of whom were ≥ 2 years old, with 2.2% meeting the UTI definition. Among these, 'clinical diagnosis' correctly identified 46.6% of positive cultures, with 94.7% specificity and an AUROC of 0.77 (95% CI 0.71 to 0.83). Four symptoms, three signs and three dipstick results were independently associated with UTI with an AUROC (95% CI; bootstrap-validated AUROC) of 0.89 (0.85 to 0.95; validated 0.88) for symptoms and signs, increasing to 0.93 (0.90 to 0.97; validated 0.90) with dipstick results. Nappy pad samples were provided from the other 2277 children, of whom 82% were < 2 years old and 1.3% met the UTI definition. 'Clinical diagnosis' correctly identified 13.3% positive cultures, with 98.5% specificity and an AUROC of 0.63 (95% CI 0.53 to 0.72). Four symptoms and two dipstick results were independently associated with UTI, with an AUROC of 0.81 (0.72 to 0.90; validated 0.78) for symptoms, increasing to 0.87 (0.80 to 0.94; validated 0.82) with the dipstick findings. A high specificity threshold for the clean-catch model was more accurate and less costly than, and as effective as, clinical judgement. The additional diagnostic utility of dipstick testing was offset by its costs. The cost-effectiveness of the nappy pad model was not clear-cut.

CONCLUSIONS

Clinicians should prioritise the use of clean-catch sampling as symptoms and signs can cost-effectively improve the identification of UTI in young children where clean catch is possible. Dipstick testing can improve targeting of antibiotic treatment, but at a higher cost than waiting for a laboratory result. Future research is needed to distinguish pathogens from contaminants, assess the impact of the clean-catch algorithm on patient outcomes, and the cost-effectiveness of presumptive versus dipstick versus laboratory-guided antibiotic treatment.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

The Diagnosis of Urinary Tract Infection in Young Children (DUTY) Study Clinical Rule: Economic Evaluation

OBJECTIVE

To estimate the cost-effectiveness of a two-step clinical rule using symptoms, signs and dipstick testing to guide the diagnosis and antibiotic treatment of urinary tract infection (UTI) in acutely unwell young children presenting to primary care.

METHODS

Decision analytic model synthesising data from a multicentre, prospective cohort study (DUTY) and the wider literature to estimate the short-term and lifetime costs and healthcare outcomes (symptomatic days, recurrent UTI, quality adjusted life years) of eight diagnostic strategies. We compared GP clinical judgement with three strategies based on a 'coefficient score' combining seven symptoms and signs independently associated with UTI and four strategies based on weighted scores according to the presence/absence of five symptoms and signs. We compared dipstick testing versus laboratory culture in children at intermediate risk of UTI.

RESULTS

Sampling, culture and antibiotic costs were lowest in high-specificity DUTY strategies (£1.22 and £1.08) compared to clinical judgement (£1.99). These strategies also approximately halved urine sampling (4.8% versus 9.1% in clinical judgement) without reducing sensitivity (58.2% versus 56.4%). Outcomes were very similar across all diagnostic strategies. High-specificity DUTY strategies were more cost-effective than clinical judgement in the short- (iNMB = £0.78 and £0.84) and long-term (iNMB =£2.31 and £2.50). Dipstick tests had poorer cost-effectiveness than laboratory culture in children at intermediate risk of UTI (iNMB = £-1.41).

CONCLUSIONS

Compared to GPs' clinical judgement, high specificity clinical rules from the DUTY study could substantially reduce urine sampling, achieving lower costs and equivalent patient outcomes. Dipstick testing children for UTI is not cost-effective.

Incidence and morbidity of urinary tract infection in a prospective cohort of children

AIM

Information on the epidemiology of childhood urinary tract infections (UTIs) is scarce and mostly based on retrospective data. This study investigated incidence rates, morbidity and risk factors for UTIs in a prospective cohort of children.

METHODS

We explored UTIs in a representative cohort of 1049 neonates from birth to 6 years of age, using maternal interviews that were verified by hospital records. The majority (88.2%) completed the first-year, and more than half (56.2%) completed the 6-year follow-up.

RESULTS

By 6 years of age, more than 10% of our sample had been affected by UTIs. The cumulative incidence for the first year of life was 3.77%, without significant differences between genders, and for one to 6 years, it was 6.81% and 5.7 times higher in girls than boys. Clinical information was available for 63 children: 25 were hospitalised, 16 suffered recurrences, 10 received prophylaxis, eight had urinary tract malformations, three required surgery, and two had impaired renal function.

CONCLUSION

UTIs affected approximately 4% and 10% of children by the ages of one and 6 years, respectively, and their incidence was related to gender and age. Morbidity was considerable, recurrences were common, and despite advances in management, long-term consequences may still be encountered.

Prevalence of urinary tract infection in acutely unwell children in general practice: a prospective study with systematic urine sampling

BACKGROUND

Urinary tract infection (UTI) in children may be associated with long-term complications that could be prevented by prompt treatment.

AIM

To determine the prevalence of UTI in acutely ill children ≤ 5 years presenting in general practice and to explore patterns of presenting symptoms and urine sampling strategies.

DESIGN AND SETTING

Prospective observational study with systematic urine sampling, in general practices in Wales, UK.

METHOD

In total, 1003 children were recruited from 13 general practices between March 2008 and July 2010. The prevalence of UTI was determined and multivariable analysis performed to determine the probability of UTI.

RESULT

Out of 597 (60.0%) children who provided urine samples within 2 days, the prevalence of UTI was 5.9% (95% confidence interval [CI] = 4.3% to 8.0%) overall, 7.3% in those < 3 years and 3.2% in 3-5 year olds. Neither a history of fever nor the absence of an alternative source of infection was associated with UTI (P = 0.64; P = 0.69, respectively). The probability of UTI in children aged ≥3 years without increased urinary frequency or dysuria was 2%. The probability of UTI was ≥5% in all other groups. Urine sampling based purely on GP suspicion would have missed 80% of UTIs, while a sampling strategy based on current guidelines would have missed 50%.

CONCLUSION

Approximately 6% of acutely unwell children presenting to UK general practice met the criteria for a laboratory diagnosis of UTI. This higher than previously recognised prior probability of UTI warrants raised awareness of the condition and suggests clinicians should lower their threshold for urine sampling in young children. The absence of fever or presence of an alternative source of infection, as emphasised in current guidelines, may not rule out UTI in young children with adequate certainty.

A survey of the management of urinary tract infection in children in primary care and comparison with the NICE guidelines

BACKGROUND

The aim of this study was to establish current practices amongst general practitioners in the West of Ireland with regard to the investigation, diagnosis and management of urinary tract infection (UTI) in children and to evaluate these practices against recently published guidelines from the National Institute for Health and Clinical Excellence (NICE).

METHODS

A postal survey was performed using a questionnaire that included short clinical scenarios. All general practices in a single health region were sent a questionnaire, cover letter and SAE. Systematic postal and telephone contact was made with non-responders. The data was analysed using SPSS version 15.

RESULTS

Sixty-nine general practitioners were included in the study and 50 (72%) responded to the questionnaire. All respondents agreed that it is important to consider diagnosis of UTI in all children with unexplained fever. Doctors accurately identified relevant risk factors for UTI in the majority (87%) of cases. In collecting urine samples from a one year old child, 80% of respondents recommended the use of a urine collection bag and the remaining 20% recommended collection of a clean catch sample. Respondents differed greatly in their practice with regard to detailed investigation and specialist referral after a first episode of UTI. Co-amoxiclav was the most frequently used antibiotic for the treatment of cystitis, with most doctors prescribing a five day course.

CONCLUSIONS

In general, this study reveals a high level of clinical knowledge amongst doctors treating children with UTI in primary care in the catchment area of County Mayo. However, it also demonstrates wide variation in practice with regard to detailed investigation and specialist referral. The common practice of prescribing long courses of antibiotics when treating lower urinary tract infection is at variance with NICE's recommendation of a three day course of antibiotics for cystitis in children over three months of age when there are no atypical features.

Prevalence of urinary tract infection in childhood: a meta-analysis

BACKGROUND

Knowledge of baseline risk of urinary tract infection can help clinicians make informed diagnostic and therapeutic decisions. We conducted a meta-analysis to determine the pooled prevalence of urinary tract infection (UTI) in children by age, gender, race, and circumcision status.

METHODS

MEDLINE and EMBASE databases were searched for articles about pediatric urinary tract infection. Search terms included urinary tract infection, cystitis, pyelonephritis, prevalence and incidence. We included articles in our review if they contained data on the prevalence of UTI in children 0-19 years of age presenting with symptoms of UTI. Of the 51 articles with data on UTI prevalence, 18 met all inclusion criteria. Two evaluators independently reviewed, rated, and abstracted data from each article.

RESULTS

Among infants presenting with fever, the overall prevalence (and 95% confidence interval) of UTI was 7.0% (CI: 5.5-8.4). The pooled prevalence rates of febrile UTIs in females aged 0-3 months, 3-6 months, 6-12 months, and >12 months was 7.5%, 5.7%, 8.3%, and 2.1% respectively. Among febrile male infants less than 3 months of age, 2.4% (CI: 1.4-3.5) of circumcised males and 20.1% (CI: 16.8-23.4) of uncircumcised males had a UTI. For the 4 studies that reported UTI prevalence by race, UTI rates were higher among white infants 8.0% (CI: 5.1-11.0) than among black infants 4.7% (CI: 2.1-7.3). Among older children (<19 years) with urinary symptoms, the pooled prevalence of UTI (both febrile and afebrile) was 7.8% (CI: 6.6-8.9).

CONCLUSIONS

Prevalence rates of UTI varied by age, gender, race, and circumcision status. Uncircumcised male infants less than 3 months of age and females less than 12 months of age had the highest baseline prevalence of UTI. Prevalence estimates can help clinicians make informed decisions regarding diagnostic testing in children presenting with signs and symptoms of urinary tract infection.

Incidence rates and management of urinary tract infections among children in Dutch general practice: results from a nation-wide registration study

Background

We aimed to investigate incidence rates of urinary tract infections in Dutch general practice and their association with gender, season and urbanisation level, and to analyse prescription and referral in case of urinary tract infections.

Method

During one calendar year, 195 general practitioners in 104 practices in the Netherlands registered all their patient contacts. This study was performed by the Netherlands Institute for Health Services Research (NIVEL) in 2001. Of 82,053 children aged 0 to 18 years, the following variables were collected: number of episodes per patient, number of contacts per episode, month of the year in which the diagnosis of urinary tract infection was made, age, gender, urbanisation level, drug prescription and referral.

Results

The overall incidence rate was 19 episodes per 1000 person years. The incidence rate in girls was 8 times as high as in boys. The incidence rate in smaller cities and rural areas was 2 times as high as in the three largest cities. Throughout the year, incidence rates varied with a decrease in summertime for children at the age of 0 to 12 years. Of the prescriptions, 66% were in accordance with current guidelines, but only 18% of the children who had an indication were actually referred.

Conclusion

This study shows that incidence rates of urinary tract infections are not only related to gender and season, but also to urbanisation. General practitioners in the Netherlands frequently do not follow the clinical guidelines for urinary tract infections, especially with respect to referral.

Evaluation of a service development to increase detection of urinary tract infections in children

RATIONALE, AIMS AND OBJECTIVES

It is suspected that childhood urinary tract infection (UTI) remains under-diagnosed in primary care, and is consequently the cause of subsequent morbidity from renal scarring, hypertension and eventual renal failure. Practice-based education and service developments were undertaken to try to improve the detection of childhood UTI.

METHODS

A controlled before-and-after intervention study was conducted. The educational and service developments promoted awareness of and greater testing for UTI among children less than two years of age presenting with febrile illness or other potentially relevant symptoms or signs. Appropriate diagnostic equipment was provided.

RESULTS AND CONCLUSIONS

More urine samples were sent by the intervention practices but without a concomitant increase in detection of UTIs. This may indicate that current practice is approaching near maximal detection of UTI in young children.

Unexplained extra visits to general practitioners before the diagnosis of first urinary tract infection: a case-control study

AIMS

To determine: (1) whether children diagnosed with a urinary tract infection (UTI) visited their general practitioner (GP) more frequently before the diagnosis of UTI was established compared to children never diagnosed with a UTI; and (2) whether those children with evidence of renal scarring at their first diagnosed UTI visited their GPs more frequently before diagnosis compared to children who did not have evidence of renal scarring when their first UTI was investigated.

METHODS

Case-control study of 77 children with a UTI identified from a hospital radiology database (37 with and 40 without renal scarring), and 77 age, sex, and general practice matched controls. Main outcome measures were entries in general practice clinical records for types of illness, antibiotic prescriptions, and urine samples requested prior to the diagnosis of first UTI (cases) or equivalent time periods for controls.

RESULTS

Cases had a mean 2.94 additional visits or 21% more visits (95% CI 1% to 41%) in the period (mean 2.4 years) prior to the visit at which their first UTI was diagnosed, including a mean 2.5 additional visits or 23% more visits for infectious illness (95% CI 1% to 45%). The cases had 114% (95% CI 41% to 184%) more visits for symptoms relating to the genitourinary tract, though the actual number of these visits was small. They were febrile at 49% more visits (95% CI 1% to 99%) and received significantly more courses of antibiotics than controls (5.2 v 4.1). They had more urine samples requested (37 v 3). Both the cases with and without renal scarring had similar excess GP visits.

CONCLUSION

Compared to controls, children diagnosed with a first UTI had more visits at which symptoms of infection were recorded and more antibiotics prescribed prior to the visit at which the first UTI was diagnosed. These excess visits may have included undiagnosed UTIs. Both those with and without renal scarring had a similar degree of excess visits; additional aetiological factors must have played a role in scar formation.

Technical report: urinary tract infections in febrile infants and young children. The Urinary Tract Subcommittee of the American Academy of Pediatrics Committee on Quality Improvement

OVERVIEW

The Urinary Tract Subcommittee of the American Academy of Pediatrics Committee on Quality Improvement has analyzed alternative strategies for the diagnosis and management of urinary tract infection (UTI) in children. The target population is limited to children between 2 months and 2 years of age who are examined because of fever without an obvious cause. Diagnosis and management of UTI in this group are especially challenging for these three reasons: 1) the manifestation of UTI tends to be nonspecific, and cases may be missed easily; 2) clean voided midstream urine specimens rarely can be obtained, leaving only urine collection methods that are invasive (transurethral catheterization or bladder tap) or result in nonspecific test results (bag urine); and 3) a substantial number of infants with UTI also may have structural or functional abnormalities of the urinary tract that put them at risk for ongoing renal damage, hypertension, and end-stage renal disease (ESRD).

METHODS

To examine alternative management strategies for UTI in infants, a conceptual model of the steps in diagnosis and management of UTI was developed. The model was expanded into a decision tree. Probabilities for branch points in the decision tree were obtained by review of the literature on childhood UTI. Data were extracted on standardized forms. Cost data were obtained by literature review and from hospital billing data. The data were collated into evidence tables. Analysis of the decision tree was used to produce risk tables and incremental cost-effectiveness ratios for alternative strategies.

RESULTS

Based on the results of this analysis and, when necessary, consensus opinion, the Committee developed recommendations for the management of UTI in this population. This document provides the evidence the Subcommittee used in the development of its recommendations.

CONCLUSIONS

The Subcommittee agreed that the objective of the practice parameter would be to minimize the risk of chronic renal damage within reasonable economic constraints. Steps involved in achieving these objectives are: 1) identifying UTI; 2) short-term treatment of UTI; and 3) evaluation for urinary tract abnormalities.

Long-term follow up to determine the prognostic value of imaging after urinary tract infections. Part 1: Reflux

In 3646 children with at least one confirmed urinary tract infection the prevalence of vesicoureteric reflux at presentation was correlated with progressive renal damage during follow up of not less than two and up to 16 years. Reflux was not demonstrated either at presentation or at any subsequent time in almost one half of the children who suffered progressive renal damage and was not a risk factor for progressive renal damage in boys under 1 year. It was an important risk factor in boys over 1 year and in girls of any age. The risk of progressive renal damage in children in whom micturating cystourethrography (MCU) did not reveal vesicoureteric reflux was substantially greater than in those who indirect isotope voiding study (IVS) did not show reflux. The risk of deterioration for those in whom reflux was demonstrated was similar for both techniques. This discrepancy indicates an appreciably higher false negative rate for the MCU than the IVS. Dilatation of the renal pelvis detected by ultrasound was associated with a significantly increased risk of progressive damage only when associated with reflux, but most children with progressive damage did not have a dilated collecting system at presentation.

The selective use of dimercaptosuccinic acid renal scans in children with vesicoureteral reflux

Dimercaptosuccinic acid (DMSA) renal scans were performed on 75 children (115 refluxing renal units) to determine the efficacy of routine scanning in patients with various grades of vesicoureteral reflux. Cystourethrography demonstrated grades I and II reflux in 75 renal units and grades III to V in 40. Of the patients 51 presented with febrile urinary tract infection and 24 were asymptomatic (patients presenting with nonfebrile urinary tract infections or those undergoing sibling screening). Renal ultrasounds were performed in 60 patients. All patients were initially managed with medical therapy and 19 (25%) ultimately underwent antireflux surgery. DMSA scans demonstrated scarring in 17 of 40 renal units (43%) of patients with high grade vesicoureteral reflux and 6 of 75 renal units (8%) of those with low grade reflux. Renal ultrasounds that were interpreted as normal always correlated to a normal DMSA scan in asymptomatic patients. In patients presenting with febrile urinary tract infections the correlation between ultrasound and DMSA scan was inconsistent. We advocate a tailored approach in the evaluation of patients with vesicoureteral reflux. Renal sonography may be sufficient in the assessment of renal scarring in asymptomatic patients with reflux and those with low grade reflux. Conversely, in patients with high grade vesicoureteral reflux, a history of febrile urinary tract infections and abnormal renal ultrasound DMSA renal scans appear to be most useful.

Current imaging of childhood urinary infections: prospective survey

OBJECTIVES

To assess whether ultrasonography alone is adequate for routine screening of childhood urinary infection, whether clinical features determine the need for further investigations, and which investigations are most appropriate.

DESIGN

Prospective survey of children with proved urinary infection and a preinvestigation record of clinical features. Ultrasonography and intravenous urography were routine, with choice of further studies determined by ultrasonographic findings.

SETTING

A children's hospital and two district general hospitals in Mersey region.

MAIN OUTCOME MEASURES

Sensitivity and specificity of ultrasonography both generally and in relation to clinical features. Accuracy of intravenous urography compared with radioisotope examinations.

RESULTS

Specificity of ultrasonography was good (99% (95% confidence interval 96% to 100%)) but sensitivity modest (43% (32% to 55%)), principally with respect to detecting vesicoureteric reflux and renal scarring. Among older children (aged 2-10 years) with positive ultrasound results and fever or vomiting the sensitivity in detecting reflux (with and without renal scarring) was 78% (62% to 89%) and the specificity 69% (60% to 78%); in detecting renal scarring (with and without reflux) the sensitivity was 100% (80% to 100%) and specificity 65% (56% to 74%). Renal scarring and obstructive uropathies were better assessed by radioisotope examinations than by intravenous urography.

CONCLUSIONS

Ultrasonography alone is inadequate for routine screening of childhood urinary infection. Though further investigations remain advisable in infants, in older children they can be restricted to a minority who have positive ultrasound examinations or have had fever or vomiting. Radioisotope examinations largely eliminate the need for intravenous urography.

Imaging in urinary tract infection

The relationship of vesicoureteric reflex (VUR) and renal scarring was studied in 94 children (188 kidneys) with proved urinary tract infection in a district general hospital. There were 61 girls and 33 boys, with nine girls and 17 boys aged less than 1 year, 31 girls and nine boys aged between 1 and 5 years, the remaining 28 children were over 5 years of age. All children had a micturating cystourethrogram and a 99mTc (technetium) dimercaptosuccinic acid (DMSA) scan. Forty two of the 188 kidneys were scarred and 70 of the kidneys had VUR. Only 37.1% of the kidneys with reflux were scarred but 61.9% of the scarred kidneys had VUR. In children of less than 1 year, 48% of kidneys with VUR were scarred whereas 70.6% of scarred kidneys had reflux. In children between 1 and 5 years of age only 36.4% of kidneys with VUR were scarred but 63.2% of scarred kidneys had VUR. There is good correlation between the detection of a scarred kidney on DMSA and the presence of vesicoureteric reflux. However the detection of reflux particularly in children over 1 year of age shows poor correlation with renal scarring. This suggests that the primary imaging in children over 1 year of age presenting with a urinary tract infection should be of the kidney: a cystogram should be performed only if the DMSA scan is abnormal.

A practical approach to evaluating urinary tract infection in children

All children with urinary tract infections should be investigated by either excretory urography or abdominal X-ray, ultrasonography and technetium 99m - dimercaptosuccinic acid scintigraphy. Patients in the following categories should also have micturating (voiding) cystourethrography to diagnose or exclude vesico-ureteral reflux: infants aged less than 1 year, children with recurrent (second or subsequent) infections, children with clinically diagnosed acute pyelonephritis and those with a family history of reflux or chronic pyelonephritis. Cystography can safely be omitted in children over 1 year of age with unscarred kidneys and none of the additional risk factors listed. They should be followed for 1-2 years following the first infection for evidence of recurrence.

Paediatric nuclear medicine

Until the 1980s no serious attempts were made to develop paediatric nuclear medicine, as for various reasons many centres were reluctant to perform radionuclide examinations on children. Then two books were published on paediatric nuclear medicine in 1984 and 1985, respectively. In 1987, a group of physicians formed an informal club of paediatricians and nuclear medicine specialists in an effort to improve the relationship and cooperation between these specialties. Carrying out nuclear medicine examinations on children requires a completely different approach than on adults. Suggestions are made and tips given, and the specific problems involved are discussed in detail.

How well do general practitioners manage urinary problems in children? South Bedfordshire Practitioners' Group

Thirteen general practitioners examined the notes of 1072 patients born in 1974 for evidence of enuresis, suspected urinary tract infection, and renal tract imaging. Of these children 63 (5.9%) had presented with enuresis -6.7% of the boys and 5.0% of the girls. Of the 63 children 65.1% had had midstream urinalysis. One hundred and ninety five children (18.2%, 64 boys and 131 girls) had experienced 303 episodes of possible urinary infections. Midstream urine samples were obtained in 80.2% of episodes and 17.7% of samples were positive. Ten boys (1.9% of the total) and 28 girls (5.2%) had proven infections. Only 14 of these 38 children (36.8%) had undergone renal tract imaging, 30.9% of the boys and 39.3% of the girls. All imaging was normal except in the case of one girl whose micturating cystourethrogram showed reflux. Fifteen other children were investigated; two further abnormalities were detected, one renal scar with reflux and one duplex system. This study demonstrates deficiencies in the investigation and follow up of children with urinary problems by general practitioners. Possible means of improvement are discussed.

Children with urinary tract infection; a critical diagnostic pathway

A protocol for the radiological investigation of children with urinary tract infection was introduced in a district general hospital in 1985. Every boy, and every girl under 5 years was investigated after one documented infection, and every girl over 5 years after two infections. Each child had an abdominal radiograph and a sonar scan of the urinary tract. Four years later the results were assessed by reviewing the radiology file or contacting the general practitioner of each of the first 200 children examined. Ten of 15 children diagnosed as not normal on screening and investigated further had an abnormality confirmed. Four of 25 children thought normal on screening had minor abnormalities shown on further examination. The results are assessed in the light of a review of recent literature and indicate that this screening protocol is efficient and effective.

Renal scarring secondary to vesicoureteric reflux. Critical assessment and new grading

One hundred and fifty children with proven urinary tract infection who were assessed by renal ultrasound (U/S), intravenous urography (IVU) and dimercaptosuccinic acid (99mTc DMSA) scan, were studied to identify the sensitivity of each examination and the pick-up rate of renal scarring secondary to vesicoureteric reflux. Sixty-three of these children who had the examinations carried out within a 6-month period were assessed in detail. A DMSA scan is the most accurate method of detecting early renal scars in the young age group (0-2 and 2-5 years), followed by ultrasound. The examinations are equally sensitive over the age of 5. A new grading system of the severity of renal scarring is presented.

Urinary tract infection in primary health care in northern Sweden. I. Epidemiology

During a 12-month study at the primary health care (PHC) centre in Vännäs (population 8,000) 632 encounters by 265 individuals because of suspected urinary tract infection (UTI) or control after treatment resulted in 279 episodes of bacteriuria in 185 patients. Nine per cent of the episodes concerned patients with indwelling catheter or incontinence requiring other aids. Symptoms of lower and higher UTI were recorded in 56 and 12%, respectively, whereas one third of the episodes were associated with vague or no symptoms and discovered mainly at planned treatment controls. The annual incidence of bacteriuria recorded increased from 0.5% in the first decade of life to more than 10% in the age group 90-100 years. Male UTI comprised 13% of the episodes, increased after middle age and contributed 40% at greater than or equal to 80 years of age. The risk of recurrence (on average 50% during the year studied) was relatively independent of sex and age. No seasonal variation of UTI was observed except for a peak in late summer due to Staphylococcus saprophyticus confined to females aged 15-64 years and causing 28% of the episodes in August. Although UTI in PHC appears to be similar globally it represents a far more complex patient group than indicated by the UTI drug trials frequently published.

Prevalence of calcified upper urinary tract stone disease in a random population survey. Report of a combined study of general practitioners and hospital staff

There are few randomised studies specifically designed to establish the prevalence of upper urinary tract stone disease. The present random study sampled a population of 7000 in the central belt of Scotland. Three thousand three hundred and ninety-eight subjects were X-rayed and possible calcified upper tract stones were further investigated, revealing a prevalence rate of 3.5% of the total surveyed population. Socio-economic characteristics of the population were determined, such as occupation, history of previous infection, stone disease and backache. Simple urine and blood analyses were undertaken. There was no difference in stone prevalence between males and females (1.03:1) as distinct from treated stone patients. There were no differences between the sexes with respect to family history of stone disease but females have a greater chance of having had previous urinary tract infection.

Urinary tract infection in children

During 1968-77, 572 consecutive children with one or more positive urine cultures who were referred by their family doctors to one paediatric surgical outpatient clinic were investigated and prospectively recorded. An abnormality requiring treatment was found in 45%. The yield of positive findings and need for operation were greater in those referred after one infection than in those with recurrent infection. Among those under 2 years old 90% had an abnormality. One third of children with vesicoureteric reflux showed renal scarring at the time of first attendance. The results of medical and surgical treatment over five to 15 years of follow up were analysed. They emphasised the importance of culturing the urine whenever there may be urinary infection in a child and of investigating immediately those with a positive urine culture.

Acute abdominal pain in children

During a twelve-month period, 416 children with acute abdominal pain required emergency admission to Southampton General Hospital; 46% had operations. Appendicitis was the commonest organic cause of acute abdominal pain identified (31%). Constipation (9%) can present as acute abdominal pain simulating appendicitis. All children should have a urine sample examined microscopically and the finding of significant pyuria is suggestive, but not diagnostic, of a urinary tract infection (7%). Mesenteric adenitis, which can only be diagnosed with certainty at laparotomy, was less common (4%). Despite careful clinical assessment and follow up, 45% of children in this series remained undiagnosed. Sedation but not analgesia may assist in the diagnosis of the acute abdomen in children.