Lateral-flow immunoassay as a diagnostic test for influenza type A and B in children

Abstract

Background The diagnosis of influenza remains difficult toestablish because of its similar symptoms to those of respiratoryinfection caused by other viruses. The “gold standard” for thediagnosis of influenza is viral culture, which takes time to gainthe result and is expensive as well. A simple, rapid, and easilyused tool for detection of influenza virus type A and B is needed.Objective To assess the accuracy of lateral-flow immunoassay withQuick Vue Influenza A+B ® in detecting influenza virus of typeA and B.Methods This was an observational study designed for diagnostictest. The subjects were children aged 0-14 years old presentingwith acute respiratory infection in primary Health Care Jetis ,Godean I, Godean II and Prof. Dr. Sardjito Hospital Yogyakarta,from October 2005 to May 2007. Specimens were collected fromboth the anterior nares and the throat by physicians for lateral-flow immunoassay with Quick Vue Influenza A+B ® and viralculture as gold standard. Lateral-flow immunoassay was done ineach study centre, nasal specimen was placed in an extractionreagent tube and sent to NAMRU II laboratory.Results There were 255 children enrolled in this study. Lateral-flow immunoassay by Quick Vue Influenza A+B ® has sensitivity70% (CI95% 6;83%), specificity 93% (CI95% 90;97%), positivepredictive value 68% (CI95% 54;82%), negative predictive value94% (CI95% 91;97%), positive likelihood ratio 10,56 (CI95%6,14;18,19) and negative likelihood ratio 0,32 (CI95% 0,21; 0,51).Conclusion Lateral-flow immunoassay (Quick Vue InfluenzaA+B ® ), nasal swab specimen is not accurate to detect influenzavirus A and B in children.