1. Fever in infants: Evaluation by
UK NICE fever guideline and Rochester criteria
Christian Harkensee1,2, Sophie Vaughan2, A Moran3, Charlie Massey3, Seilesh Kadambari4, Michael Sharland1,4
1Department of Paediatric Infectious Diseases, St George’s Hospital, London, UK; 2Department of Paediatrics, Division of Paediatric Infectious Diseases, National University Hospital Singapore; 3Department of Paediatrics, St George’s Hospital, London, UK; 4Paediatric Infectious Diseases Research Group,
St George’s University, London, UK . Contact:
Abstract
Background and aims: Febrile infants commonly have viral infections difficult to distinguish from rarer serious bacterial infection (SBI), despite risk-criteria approaches (NICE, Rochester), leading to unnecessary antibiotic treatment and admission. This study compares the NICE fever guideline and Rochester criteria on a cohort of infants from a UK tertiary paediatric unit.
Methods: This observational study recruited infants admitted and treated for sepsis over a six months period. Clinical details, laboratory results and outcomes were obtained prospectively.
Results: Of 61 infants admitted, 10 had SBI, 19 had proven viral infections and in 32 infants no pathogen was found. All infants received antibiotic treatment and recovered.
Using NICE criteria, 5 infants were categorized as ‘green’, 10 as ‘amber’ and 46 as ‘red’ (of which 21 had fever as the only feature). All SBI fell within the ‘red’ category except one case of sepsis classed as ‘amber’. Five urinary tract infections (UTI) fell within the subgroup of ‘red’ infants with fever as only feature. Applying Rochester criteria, 51 infants were determined as high risk, encompassing all SBI.
Conclusions: The NICE fever guideline is a useful tool for the assessment of febrile infants. It classes fewer infants as high risk for SBI than Rochester and may therefore avoid some unnecessary use of antibiotics. Conversely, early or mild cases of SBI may escape categorization as high risk. A subgroup of the ‘red’ category included well infants who had fever as the only feature – a high proportion of these had UTI.
Green=5
LP done=3 normal=33
No SBI
WCC: normal=4, abnormal=1
CRP: normal=4, abnormal=1
Urine done=22, normal=2
Amber=10
LP done=7, normal=7
GBS sepsis=1
WCC: normal=8, abnormal=2
CRP: normal=8, abnormal=2
Urine: done=8, normal=6, abnormal=2
Red=46
fever only=21
LP: done=11, normal=10, abnormal=1
UTI=7
WCC: normal=14, abnormal=7
CRP: normal=15, abnormal=6
Urine: done=18, normal=12, abnormal=6
Other signs=25
LP: done=21, normal=14, abnormal=7
GBS meningitis=1
WCC: normal=16, abnormal=9
E. coli meningitis and UTI=1
CRP: normal=8, abnormal=17
Urine: done=22, normal:=17, abnormal=5
Introduction
Febrile young infants represent to the clinician a challenge in diagnosis and management. Rochester criteria are a clinical risk score, supported by basic laboratory, have been used to distinguish infants with high risk of serious bacterial infection (SBI), which are more likely to be admitted ant to receive empirical antibiotics, from those with low risk, which could be observed with antibiotics being withheld until culture results would be available. Large prospective studies have shown that the rate of SBI in high risk infants is between %, whereas the rate in the low risk group is <3%. Using Rochester criteria, 32-80% of all febrile infants fall into the high risk category, potentially leading to overtreatment with antibiotics and unnecessary admission . The NICE fever guideline, published in 2007, aims to refine clinical risk scoring but has not been prospectively validated. This study pilots validation of the NICE guideline criteria by prospectively scoring a cohort of febrile infants by both Rochester and NICE criteria.
High risk=51
Clinically unwell: 18
Abnormal WCC: 19
Abnormal urine WCC: 14
Abnormal CRP: 36
Abnormal CSF WCC: 8
Low risk=10
A total of 61 patients were recruited; with an age distribution skewed towards younger infants (age 0-4 weeks=27, 5-8 weeks=14, 9-12 weeks=7, >12 weeks=13). Average inpatient stay was 3.4 days (47 patients were discharged by day 4). All patients were treated with iv antibiotics under a working diagnosis of sepsis, with guideline adherence in 54 patients. All patients had a peripheral WCC and CRP performed, 50 patients had urine samples taken, and 47 patients underwent LP. Ten patients were diagnosed with SBI (UTI=7, sepsis by group B streptococcus=1, meningitis by group B streptococcus=1, meningitis and UTI by E. coli=1). Viral infection was proven in 19 patients, which included respiratory viruses (RSV, influenza, metapneumovirus, parechovirus)=8, HSV=2, rotavirus=2 and enterovirus=7 (of which three were CNS infections). In 32 cases, no infectious agent was identified.
Rochester criteria identified all patients with SBI (see table). Using NICE criteria, all but one SBI (early group B streptococcal sepsis) would have fallen into the red category (table 3). All urinary tract infections were in children <3 months old and with fever as the only clinical feature Applying Rochester criteria, all patients with SBI had at least two or more high risk criteria.
Table 3: Results of scoring by NICE criteria
Table 2: Results of scoring by Rochester criteria
Results
Study Design & Methodology
Infants between 0-6 months of age admitted to St George’s Hospital in London between July and December 2011after presenting to the children’s A&E department where included in this prospective study. The study cohort includes all infants who had a full septic screen (blood/urine/CSF culture) over the six month period, and all infants admitted for a febrile illness during the month of December 2011 (regardless of completeness of septic screen). All children were investigated and treated according to existing hospital guidelines (which do not incorporate Rochester or NICE guideline criteria). After initial assessment ,laboratory tests, and treatment decisions all patients were scored by an independent clinicians using the Rochester and NICE criteria. Data on microbiological and clinical outcome were prospectively collected, and follow-up after discharge was monitored for a minimum of 3 months.
jghg
Age
0-6 months
Fever
>38 C
Clinical appearance
well/unwell
Peripheral WCC (normal)
<5000->15000 cells/ɥl
Urine WCC microscopy
(normal)
<10/mm3
CSF WCC (normal)
CRP (normal)
<5 mg/L
Discussion & Conclusions
This study is one of the first to give some indication on the validity of NICE fever guideline criteria. Although larger studies are necessary, these data indicate that the NICE fever guideline criteria provide a sensitivity similar to that of Rochester criteria. Patients in the green and amber categories may not need antibiotics or these could be withheld under close clinical monitoring, thus providing a scope for reduced antibiotic use. Urinary tract infection is the most common SBI in infants, highlighting the importance that obtaining appropriate urine samples in any febrile infant prior to starting antibiotics is essential. This was not done in a sixths of patients and is a diagnosis that could have been missed.
Table 1: Rochester criteria applied in this study