[Comparison of four rapid diagnostic kits using immunochromatography to detect influenza B viruses]

We compared the usefulness of 4 rapid influenza diagnostic 1-device kits using immunochromatography, which facilitate type differentiation, i.e. ESPLINE Influenza A&B-N (Fujirebio Corp., Japan: ESPLINE), POCTEM INFLUENZA A/B (Sysmex Corp., Japan: POCTEM), Quick Vue Rapid SP influ (Quidel Corp., U.S.A.: Quick Vue), and Capilia Flu A + B (TAUNS Corp., Japan: Capilia), in 278 children in whom influenza infection was suspected in 2004 and 2005. Nasopharyngeal aspirates were diluted for virus isolation and residual samples were centrifuged. Using the supernatant, we conducted rapid diagnosis testing. Influenza virus AH3 was isolated from 40 children, and influenza B virus from 163. Of the 40 children, the sensitivity and specificity of ESPLINE, POCTEM, Quick Vue, and Capilia were 100%/100%, 95%/100%, 98%/96%, and 98%/96%. In the 163 children, the sensitivity and specificity were 89%/100%, 87%/100%, 88%/97%, and 86%/98%. ESPLINE showed the highest sensitivity and specificity to influenza viruses AH3 and B. All kits were less sensitive to influenza B virus than to influenza A virus, however. The specificity of Quick Vue and Capilia was low; so these kits must be improved.