Challenges with new rapid influenza diagnostic tests.

Rapid influenza diagnostic tests (RIDTs) are often used at point-of-care due to their ease of use and rapidly available results. Most tests are lateral flow immunoassays that detect chromatographic changes if an influenza antigen is present in the respiratory specimen. These tests have high specificity (therefore, a positive is almost certainly a true positive) but low sensitivity (therefore, will often miss true cases).1,2 A newer immunofluorescence assay, Sofia A+B FIA (Quidel, San Diego, CA), demonstrated increased sensitivity but maintained high specificity.3 However, on December 3, 2012, Quidel issued a voluntary recall of certain lots of Sofia A+B because of false positive results.4