Factors affecting QuickVue Influenza A + B rapid test performance in the community setting.

Rapid diagnosis of influenza can facilitate timely clinical management. We evaluated the performance of the QuickVue Influenza A + B test (Quidel, San Diego, CA) in a community setting and investigated the factors affecting test sensitivity. We recruited 1008 subjects from 30 outpatient clinics in Hong Kong between February and September 2007. Each subject provided 2 pooled pairs of nose and throat swabs; 1 pair was tested by the QuickVue rapid test on site, and the other pair was sent to a laboratory for reference tests. Among 998 enrolled subjects with valid results, the rapid test had overall sensitivity of 0.68 and specificity of 0.96 compared with viral culture. Sensitivity for both influenza A and B was significantly higher for specimens with viral loads greater than 5 log(10) copies/mL. The QuickVue Influenza A + B test has similar sensitivity in point-of-care community settings to more controlled conditions.