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Three Part Question

In [febrile children presenting to the ED] does [rapid testing of Influenza virus] alter [subsequent management]?

Clinical Scenario

A baby is brought in to ED, by concerned parents, with high fever and history of generally being unwell with no clear history pointing towards any clear diagnosis or focus of infection. You wonder whether you need to proceed with a full septic screen, or whether a positive diagnosis of influenza on rapid bedside testing would be sufficient to allow safe discharge directly from the ED.

Search Strategy

PubMed, with the full 3 part question in addition to search on Cochrane and google.
((children) AND (emergency department)) AND (rapid influenza testing) AND ((Humans[Mesh]) AND ((infant[MeSH] OR child[MeSH] OR adolescent[MeSH])) ) Limited to english literature only

Search Outcome

11 articles in total were found, remaining 6 studies were selected, one was a simple review from 2005 but with no systematic/meta-analysis and thus was dropped, 2 articles were dropped, one for age consideration (study included patients up to age of 21 years), another for being incomplete (with pending results) and two others were found to be irrelevant to the clinical question on more detailed inspection. The seven remaining studies were selected for appraisal

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Noyola et al, 2000, USA	1530 pts, age 1-19 y during two consecutive confirmed influenza seasons at an urban children’s hospital	Retrospective case control study. RIT used to detect influenza A virus. RIT +ve as case control group and -ve as control group. Blood cultures used to confirm the results	Antibiotic prescription,. Duration of antibiotic treatment	In admitted pts: RIT +ve 43% vs 64% RIT -ve. p-0.04 Discharged pts RIT +ve 20% vs 53% RIT -ve p=0.04. RIT +ve 3.5 vs 5.4 days -ve p=0.03	Retrospective study Relied on electronic database for identifying pts who had RIT, then their medical records, so possible selection bias. Underlying diseases and their severity influencing the investigations not explained.
Bonner et al, 2003, USA	391 pts 2 month to 21 years during one confirmed influenza season at tertiary care urban hospital. Data/results for the sub group of 241 pts aged 2-36 months analysed and available as well.	Prospective Randomised Control Trial. One group, for which physicians were aware (PA) of RIT results and the other group for which they were unaware (PUA) of results for influenza A and B	CBC requesting	PA 0% vs 13% PUA (p<0.001)	Single influenza season results. Results not confirmed by blood cultures
			Blood cultures	PA 0% vs 11% PUA (p<0.001)
			CXR	PA 7% vs 26% PUA (p=001)
			Financial costs of investigations	PA $15 vs $92 PUA (p<0.001)
			Antibiotic usage	PA 7% vs 26% PUA (p<0.001)
			Length of emergency department stay	PA 25 vs 49 min PUA (p<0.001)
Benito-Fernández et al, 2006, USA	206 pts aged 0-36 months during two confirmed seasons at a tertiary care children’s hospital	Prospective observational study. RIT (influenza A & B) for all febrile pts, grouped by results into RIT +ve and RIT eve groups (all pts <3 months old had RIT whether febrile or not	Blood tests (CBC, CRP, blood cultures)	RIT +ve 33% vs 100% RIT -ve (p <0.01)	No randomisation. No follow up of -ve RIT patients (presumably no follow up of the positives either). No confirmatory tests by viral culture done.
			Urine analysis	RIT +ve 80% vs 100% RIT -ve (p <0.01)
			Lumbar puncture	RIT +ve 1.3% vs 21% RIT -ve (p<0.01)
			CXR	RIT +ve 14% vs 32% RIT -ve (p <0.01)
			Emergency department stay	RIT +ve 116 vs 192 min RIT -ve (p<0.01)
			Observation ward admission	RIT +ve 8.3% vs 21% RIT-ve (p<0.01)
			In-patient admission	RIT +ve 2.3% vs 16.4% RIT -ve (p<0.01)
			Antibiotic treatment	RIT +ve 0% vs 38% RIT -ve (p<0.01)
Poehling et al, 2006, USA	486 pts < 5 years during two consecutive influenza seasons at a university hospital paediatric emergency department	Prospective Randomised Control Trial. TG underwent RIT with results available to the clinician. CG had no RIT. Both groups had formal viral cultures or PCR lab testing for influenza.	Any diagnostic test done	TG 39% vs 52% CT p=0.03	No follow up. Convenience sample.
			CXR	TG 23% vs 33% CT p=0.06
			Blood count/cultures	TG 10% vs 18% CT p=0.05
Iyer et al, 2006, USA	700 pts 2-24 months during 2 influenza seasons at an urban tertiary care hospital	Prospective Quasi- Randomised Control Trial Intervention group (POCT) underwent RIT for influenza with available results. CG (ST): no RIT results available	Blood cultures	Reduction in POCT by 22.6% p=0.05	Convenience sample. Pneumococcus immunisation status & its effects on pts not considered. No follow-up
			Urine analysis	OR 0.45 vs 0.67 p=0.002
			Urine culture	OR 0.46 vs 0.67 p=0.005
Abanses et al, 2006, USA	1007 patients aged 3-36 months during one influenza season at an urban children's hospital emergency department	Prospective randomized controlled trial. Febrile patients were randomised at triage into an intervention group (TT) having RIT for influenza A and B with available results or a non-intervention group (SP) for which the physician decided the need for further testing.	RSV testing	TT 7% vs 18% SP (RR 2.5)	Failure of randomisation in TT group due to their non-adherence to their devised protocol so taken as convenience sample. Single influenza season results.
			CXR	TT 20% vs 26% SP (RR 1.3)
			CBC	TT 2.5% vs 29% SP (RR 12)
			Blood cultures	TT 2.5% vs 31% SP (RR 5.7)
			Urine analysis	TT 4.9% vs 28% SP (RR 9.2)
			Emergency department length of stay	TT 156 vs 195 min SP
			Total medical cost per patient	TT $393 vs $666 SP
Sharma et al, 2002, USA	72 patients aged 2-24 months during two consecutive influenza seasons at an urban children's hospital emergency department.	Retrospective observational study. Influenza A virus detection by RIT in two groups: those who had RIT results available (early detection; ED) and those who had diagnosis after discharge (late detection; LD).	Ceftriaxone use	ED 2% vs 24% LD p=0.006	Selection bias. Small sample size. Retrospective study relying on electronic database, so some patients could be missed if difference in tests and conditions. Physician's discretion to do RIT.
			CBC performed	ED 17% vs 44% LD p=0.02
			Urine analysis performed	ED 2% vs 24% LD p=0.006

Comment(s)

Good evidence (level 1b) is available, confirming that rapid influenza testing, when used appropriately, can be a reliable tool in assessment of febrile children attending Emergency Department and improves efficiency. However, there appears to still be some reluctance to develop any standardised protocol using rapid influenza testing in routine assessment of febrile children.

Editor Comment

CBC, complete blood count; CG, control group; CRP, C-reactive protein; pts, patients; RCT, randomised controlled trial; RIT, rapid influenza testing; RSV, respiratory syncytial virus; TG, test group.

Clinical Bottom Line

Rapid Influenza testing can have a significant impact on management of febrile children in the ED, especially at times of high influenza prevalence

References

1. Noyola DE, Demmler GJ. Effect of rapid diagnosis on management of influenza A infections. Pediatr Infect Dis J. 2000 Apr;19(4):303-7.
2. Bonner AB, Monroe KW, Talley LI et al. Impact of the rapid diagnosis of influenza on physician decision-making and patient management in the pediatric emergency department: results of a randomized, prospective, controlled trial. Pediatrics 2003 Aug;112(2):363-7.
3. Benito-Fernández, Javier, Vázquez-Ronco, Miguel A, Morteruel-Aizkuren, Elvira et al. Impact of Rapid Viral Testing for Influenza A and B Viruses on Management of Febrile Infants Without Signs of Focal Infection. Paed Inf Dis J 2006; 25(12):1153-1157.
4. Poehling KA, Zhu Y, Tang YW et al. Accuracy and impact of a point-of-care rapid influenza test in young children with respiratory illnesses. Arch Pediatr Adolesc Med 2006 Jul;160(7):713-8.
5. Iyer SB, Gerber MA, Pomerantz WJ et al. Effect of Point-of-care Influenza Testing on Management of Febrile Children Acad Emerg Med 2006; 13(12): 1259-1268.
6. Abanses JC, Dowd MD, Simon SD, et al. Impact of rapid influenza testing at triage on management of febrile infants and young children. Pediatr Emerg Care 2006;22:145-9.
7. Sharma V, Dowd MD, Slaughter AJ, et al. Effect of rapid diagnosis of influenza virus type a on the emergency department management of febrile infants and toddlers. Arch Pediatr Adolesc Med 2002;156:41-3.