Afebrile Infants With UTI and the Risk for Bacteraemia

Journal ClubSheffield Children’s Hospital

Naheed Maher

7th January 2015

Aim

Does presence of fever (other risk factors) determine risk of bacteraemia in very young infants with UTI

Case Presentation• 40 days old baby, presented with vomiting and reduced

intake• Well on examination• Urine Positive microscopy WCC 2+ • Urine culture E Coli 10 -5 cfu/ml• Blood culture No growth at 48 hours• Treated with IV antibiotics • Further investigations requested

Clinical Questions• Population: infants under 3 months of age with UTI• Intervention (exposure): Fever (risk factors)• Comparison: No fever (risk factors)• Outcome: bacteraemia • Design: prognostic/ analytic observations/cross sectional

Afebrile Very Young Infants with Urinary Tract Infection and the Risk for Bacteraemia

Hernandez-Bou S.,Trenchs V., Alercon M. & Luaces C. Barcelona, Spain

The Pediatric Infectious Disease Journal Volume 33,number3, March 2014

Current Practice: NICE Guidelines• Infants < 3 months should be treated in line with

guideline on children with feverish illness – Parental antibiotics in infants younger than 1 month with fever– All infants aged 1-3 months with fever who appear unwell– Infants aged 1-3 months with WBC of <5 or >15 x 10-9

Current practiceSCH guidelines: for children < 3 month

– Treat with parenteral antibiotics in line with guidelines for management of feverish child 1.9 (Urinary Tract Infection 7.1, D and E)

– Febrile children <3 months should have full septic screen and treated with Cefotaxime (+ amoxicillin) (1.9 febrile children under 5 years without focus)

Methods• Retrospective review of electronic records of infants

attending Paediatric ED with discharge diagnosis of UTI• Infants aged 29 to 90 days• September 2006 to May 2013• Inclusion criteria: Positive Urine and blood cultures• Exclusion criteria: Infants without Blood culture

Definitions used• Fever: rectal temperature ≥ 38, axillary ≥ 37.5 • Positive urine analysis: any organism visualised on

Gram staining• Positive urine culture: growth of ≥ 50,000cfu/ml of

single pathogen from catheterised specimen• Bacteraemia: positive blood culture with same

organism recovered from urine • Adverse events: bacteraemia, meningitis,

Abscess of urinary tract , requiring drainage

Outcome measures• Bacteraemia rates in relation to:

– Age– High risk medical history– Fever– Abnormal Paediatric Assessment triangle (PAT) in ED

– Blood test results (WBC including ANC and peripheral blood band count, CRP, PCT)

Results

Results

Discussion• Rate of bacteraemia 2.9 % (previously reported

2 to 21 %)

• “We hypothesize that these very young infants may not be considered a priori as low-risk patients for developing a serious illness, due to immature thermoregulation, as is the case in neonates.”

Discussion• “The 2 afebrile patients in our study with a

positive BC were very young (30 and 37 days old, respectively) infants, close to neonates. According to this finding, we believe that afebrile young infants with UTI, especially those younger than 60 days, should not be considered as low-risk patients for bacteremia.”

• Small number of afeberile infants (22 %)• Suggested a multicentre prospective study

Discussion• “As in previous studies, we found a higher

prevalence of bacteremia among children aged 29 to 59 days with respect to children aged 60 to 90 days, although the difference was not statistically significant.”

• Outpatient management in infants older than 2 month by oral antibiotic recommended by American Academy of Pediatrics and Italian Society of Paediatric Nephrology

Weakness • Retrospective design• PCT not measured in 21 %• Difference in proportion of febrile and afebrile infants

Authors’ Conclusion• “...fever was not a predicting factor for

bacteremia in very young children with an UTI,....”

• “...well-appearing infants aged 29 to 90 days with a UTI and a PCT value <0.7 ng/mL were at very low risk of bacteremia...”

Screening Questions1. Did the study address a clearly focused question?

– Specified population (29 to 90 days)– Clear health measures

2. Did the authors use an appropriate method to answer their question?

3. Were the subjects recruited in an acceptable way?– sample representative of same population– Everybody included who should have been included

4. Were the measures accurately measured to reduce bias?– Subjective or objective measures– validation of measures

5. Were the data collection in a way that addressed the research issue?– description and justification of data collection

6. Did the study have enough participants to minimize the play of chance?

– Results precise enough to make a decision – Power calculation used?

7. How are the results presented and what is the main results?– How are the results expressed?– Size / meaningful / bottom -line

8. Was the data analysis sufficiently rigorous?– In-depth description of analysis process– Sufficient data to support the findings

9. Is there a clear statement of findings

10. Can the results be applied to the local population?

11. How valuable is the research?

Summary • Fever alone cannot predict risk of bacteraemia• However there is scope for other factors used in

combination to identify bacteraemia risk in infants with UTI

THANK YOU!Special Thanks to Sarah Massey