Abstract

Background: A low cost colloidal gold immunochromatographic assay (GICA) for rapid detection of influenza A virus was developed. The assay was evaluated in this study.

Methods: Six hundred and twenty-six patients were enrolled. All patients contributed two pharyngeal swabs, one used for colloidal gold immunochromatographic rapid assay for influenza A virus immediately after the collection of specimen and one used for real-time reverse transcriptase polymerase chain reaction (RT-PCR) test or virus culture at the Centers for Disease Control and Prevention (CDC) influenza network laboratory.

Result: In reference to viral culture, GICA influenza A test demonstrated a sensitivity of 64%, a specificity of 95% and an overall accuracy of 93%. Consistency between the GICA test and virus culture assay is moderate, with Kappa being 0.46. In reference to RT-PCR, GICA test demonstrated considerable high sensitivity (74%) and specificity (86%), with Kappa value being 0.61 and overall accuracy of 81%. There was no significant difference between GICA test and virus culture/RT-PCR on the detected positive rates of influenza A cases.

Conclusions: GICA is a reliable, rapid, convenient and inexpensive test for the screening and diagnosis of influenza A disease. Given its lower cost than other rapid tests, the GICA test has the great potential in the management of influenza A disease in resource-poor countries.