Kathryn O’Brien

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.

Improving the Diagnosis and Treatment of Urinary Tract Infection in Young Children in Primary Care: Results from the DUTY Prospective Diagnostic Cohort Study

PURPOSE Up to 50% of urinary tract infections (UTIs) in young children are missed in primary care. Urine culture is essential for diagnosis, but urine collection is often difficult. Our aim was to derive and internally validate a 2-step clinical rule using (1) symptoms and signs to select children for urine collection; and (2) symptoms, signs, and dipstick testing to guide antibiotic treatment. METHODS We recruited acutely unwell children aged under 5 years from 233 primary care sites across England and Wales. Index tests were parent-reported symptoms, clinician-reported signs, urine dipstick results, and clinician opinion of UTI likelihood (clinical diagnosis before dipstick and culture). The reference standard was microbiologically confirmed UTI cultured from a clean-catch urine sample. We calculated sensitivity, specificity, and area under the receiver operator characteristic (AUROC) curve of coefficient-based (graded severity) and points-based (dichotomized) symptom/sign logistic regression models, and we then internally validated the AUROC using bootstrapping. RESULTS Three thousand thirty-six children provided urine samples, and culture results were available for 2,740 (90%). Of these results, 60 (2.2%) were positive: the clinical diagnosis was 46.6% sensitive, with an AUROC of 0.77. Previous UTI, increasing pain/crying on passing urine, increasingly smelly urine, absence of severe cough, increasing clinician impression of severe illness, abdominal tenderness on examination, and normal findings on ear examination were associated with UTI. The validated coefficient- and points-based model AUROCs were 0.87 and 0.86, respectively, increasing to 0.90 and 0.90, respectively, by adding dipstick nitrites, leukocytes, and blood. CONCLUSIONS A clinical rule based on symptoms and signs is superior to clinician diagnosis and performs well for identifying young children for noninvasive urine sampling. Dipstick results add further diagnostic value for empiric antibiotic treatment.

Childhood urinary tract infection in primary care: a prospective observational study of prevalence, diagnosis, treatment, and recovery

BACKGROUND The prevalence of targeted and serendipitous treatment for, and associated recovery from, urinary tract infection (UTI) in pre-school children is unknown. AIM To determine the frequency and suspicion of UTI in children who are acutely ill, along with details of antibiotic prescribing, its appropriateness, and whether that appropriateness impacted on symptom improvement and recovery. DESIGN AND SETTING Prospective observational cohort study in primary care sites in urban and rural areas in England and Wales. METHOD Systematic urine sampling from children aged <5 years presenting in primary care with acute illness with culture in NHS laboratories. RESULTS Of 6079 childrens urine samples, 339 (5.6%) met laboratory criteria for UTI and 162 (47.9%) were prescribed antibiotics at the initial consultation. In total, 576/7101 (8.1%) children were suspected of having a UTI prior to urine sampling, including 107 of the 338 with a UTI (clinician sensitivity 31.7%). Children with a laboratory-diagnosed UTI were more likely to be prescribed antibiotics when UTI was clinically suspected than when it was not (86.0% versus 30.3%, P<0.001). Of 231 children with unsuspected UTI, 70 (30.3%) received serendipitous antibiotics (that is, antibiotics prescribed for a different reason). Overall, 176 (52.1%) children with confirmed UTI did not receive any initial antibiotic. Organism sensitivity to the prescribed antibiotic was higher when UTI was suspected than when treated serendipitously (77.1% versus 26.0%; P<0.001). Children with UTI prescribed appropriate antibiotics at the initial consultation improved a little sooner than those with a UTI who were not prescribed appropriate antibiotics initially (3.5 days versus 4.0 days; P = 0.005). CONCLUSION Over half of children with UTI on culture were not prescribed antibiotics at first presentation. Serendipitous UTI treatment was relatively common, but often inappropriate to the organisms sensitivity. Methods for improved targeting of antibiotic treatment in children who are acutely unwell are urgently needed.

G45 The Diagnosis of Urinary Tract Infection in Young Children (DUTY) Study: The Development of a Clinical Algorithm to Improve the Recognition of Urinary Tract Infection (UTI) in Pre-School Children Presenting to Primary Care

Aim To develop a clinical algorithm based on symptoms, signs and urine dipstick results to assist the identification of children who require urine sampling, antibiotic treatment and/or laboratory analysis. Methods We conducted a diagnostic cohort study of children <5 years presenting acutely (≤28 days) unwell to primary care in the UK. We collected detailed information on the presence/absence and severity of presenting symptoms and signs, as well as socio-demographic and past medical history data. Urine was sampled by clean catch (preferred) or nappy pad, ‘dipsticked’ and sent to (i) the local NHS laboratory (the priority sample) and (ii) a reference laboratory. Blind to children’s clinical symptoms and signs, the NHS and reference laboratories processed urine samples according to their standard operating procedures. Results (preliminary) 7,163 children were recruited with NHS and research urine sample results available for 6,328 (88%) and 5,257 (73%) respectively. Of the 5,017 children without missing data and with urine results from both laboratories: mean age was 2.2 years (s.d. = 1.4); 49% were male; 54% urines via clean catch, 45% via nappy pads and 1% via bag. UTI rates were 2.8% and 3% from clean catch and pad samples respectively. Among clean catch samples, the following were independently associated with UTI: history of UTI; parental report of smelly urine; pain/crying while passing urine; clinician’s global impression of illness severity; and on dipstick: nitrites, leukocytes and blood (area under the ROC = 0.87 (95% CI 0.82 to 0.92). Among the nappy pad samples, the factors were: female gender; age; smelly urine; darker urine; and on dipstick: nitrites, leukocytes and blood (AUROC = 0.78 (0.72 to 0.83)). Conclusions Symptoms, signs and dipstick testing have diagnostic utility for UTI. These results will be developed into an algorithm to help clinicians select which should have: a urine sample obtained; a sample sent for laboratory culture and receive immediate antibiotic treatment.