A highly specific ELISA for diagnosis of 2009 influenza A (H1N1) virus infections.

Objective: Accurate and timely diagnosis is vital for the clinical management of influenza. A 2009 pandemic influenza A (H1N1)-specific enzyme-linked immunosorbent assay (ELISA) was tested with selected clinical samples.

Methods: A selection of 90 throat swab samples with various viral loads of 2009 pandemic influenza A (H1N1) were tested.

Results: Using the reverse transcriptase polymerase chain reaction as a gold standard, the overall sensitivity (0.57) was higher than that of the QuickVue Influenza A+B Test (0.43). The specificity of the ELISA was 1.0 using the selected sample set. The positive and negative predictive values were 1 and 0.4, respectively.

Conclusions: The ELISA is an easy to perform, highly specific, and fairly sensitive diagnostic tool for the 2009 pandemic influenza A (H1N1) virus infections. A strong correlation was found between viral load and specificity.