Clinical evaluation of an immunochromatography test kit, Capilia FluA, B, for rapid diagnosis of influenza

A multicenter open study using the internet was done during the influenza season of 2002/2003 to evaluate the effectiveness of antiinfluenza drugs. The study was comprised of 2008 cases of influenza diagnosed at 52 clinics in Japan. As a substudy, we assessed the sensitivity and specificity of a rapid detection kit for influenza, the Capilia FluA, B (Becton-Dickinson Japan) that utilizes the immunochromatography method. Nasal swab or pharyngeal swab specimens were collected from influenza-like illness patients. Serum samples were collected at the first visit and after 2 weeks or more. Samples for virus isolation and paired serum were obtained from 247 patients. Overall, sensitivity was 93.3% when compared with the results of virus isolation and 84.1% when compared with the results of serological diagnosis. No significant difference in sensitivity was found by sex or age. The number of days after onset that testing was done was a significant factor affecting the sensitivity of the kit. The sensitivity at day I was relatively low compared with days 2 and 3. These results indicate that the rapid detection kit for influenza, the Capilia FluA, B, has sufficient sensitivity for clinical utilization. When the kit is used with proper consideration, it can be a powerful tool for the management of influenza patients. (C) 2004 Elsevier B.V. All rights reserved.