Neat-patienting for RSV in the emergency department
We note the paper on near-patient testing (NPT) for respiratory syncytial virus (RSV) in cases of bronchiolitis by Walsh et al (1). It is an interesting paper but we suggest it fails to acknowledge one of the main uses of this particular test methodology. The test analysed also has a poorer performance than the one we use.
Bronchiolitis is a common respiratory disease in early childhood and infancy. The diagnosis is a clinical one, and should never rely on a diagnostic test for one particular virus. RSV is the main organism responsible for causing bronchiolitis in infancy, but other organisms have been described (2). As there is no specific treatment directed against RSV, or any of the other viral causes, accurate viral diagnosis is not a pre-requisite.
We have used NPT for RSV for many years. Our current NPT is BinaxNOW (R) RSV test kit (Inverness medical, UK) and we have demonstrated different results to Walsh et al using polymerase chain reaction (PCR) in the laboratory as the gold standard for comparison. Our results for comparison are: Sensitivity 90 Specificity 91 Positive predictive value 86 Negative predictive value 93
We believe the real value, however, is in allowing decisions to be made about cohorting children in times of peak bronchiolitis outbreaks, which happen every winter. This is not an issue if every child has guaranteed admission to a cubicle, with maximum isolation and reduction in cross-infection.
However in many areas this is simply not feasible. In these situations NPT for RSV is invaluable in sorting children into cohorts which maximise bed usage (3). It allows a reasonable and clinically relevant estimate of which child has RSV. Children with positive RSV test on NPT can be nursed and cared-for in an area with other children with RSV. Those that are negative can be isolated until a formal laboratory PCR test either confirms RSV - when the child can be moved to a cohort area - or otherwise when isolation can be continued. This is a better use of laboratory time and resources and which has been discussed recently (4,5).
Using this approach for many years we have successfully reduced cross -infection significantly, with better usage of scarce cubicle space (6). We do not believe that the paper as published emphasises this point, and we would like to highlight this important benefit.
Tom Beattie Kirsty McLellan. Kate Templeton.
(1) Walsh P, Overmyer C, Hancock C, Heffner J, Walker N, Nguyen T, et al. Is the interpretation of rapid antigen testing for respiratory syncytial virus as simple as positive or negative? Emerg Med J 2013 (20 August 2013, 10.1136/emermed-2013-202767). (2) American Academy of Pediatrics Subcommittee on Diagnosis and Management of,Bronchiolitis. Pediatrics 2006 Oct;118(4):1774-1793. (3) Mackenzie A, Hallam N, Mitchell E, Beattie T. Near patient testing for respiratory syncytial virus in paediatric accident and emergency: prospective pilot study. BMJ 1999 Jul 31;319(7205):289-290. (4) Moore C. Journal of Hospital Infection 2013;85:1 - 7. (5) Hallam N, Hesketh L. Paediatric viral respiratory polymerase chain reaction testing: more sensitive but less rapid and with infection control implications. J Hosp Infect 2011 Apr;77(4):367. (6) Mills JM, Harper J, Broomfield D, Templeton KE. Rapid testing for respiratory syncytial virus in a paediatric emergency department: benefits for infection control and bed management. J Hosp Infect 2011 Mar;77(3):248 -251.
Conflict of Interest:
Previous publications on near-patient testing for RSV in Emergency Departments