Clinical Usefulness of Rapid Antigen Test on the Diagnosis of Influenza

Kim, Jae Seon; Choi, Hyon Joo; Ahn, Young Min; Hwang, Young Ok

Abstract

PURPOSE
Influenza is a respiratory disease which prevails widely every year and shows high morbidity and mortality among not only chronic invalids and the old, but also among infants and young children. To prevent community-acquired influenza infection, to facilitate prompt antiviral therapy and to avoid unnecessary use of antibiotics, an easy, rapid diagnostic method for the influenza virus is needed. We evaluated a lateral-flow immunoassay (QuickVue Influenza Test), compared to viral culture. METHODS: During two consecutive years from Jan. 2004 to June 2004 and from Feb. 2005 to Jan. 2005, 408 patients who were suffering from fever, cough and/or sore throat and myalgia were enrolled in our study. A total of 408 patients were tested with QuickVue (R) (Quidel Co., San Diego, USA) influenza rapid antigen test and virus cultures at the same time. RESULTS: Of the 408 patients tested, children who showed positive results at the virus culture numbered 77; among them, 55 (71.4 percent) were type A/H3N2 and 22 (28.5 percent) were type B. QuickVue influenza test had a sensitivity of 71.4 percent and a specificity of 95.8 percent. The positive and negative predictive values were 79.7 percent and 93.5 percent, respectively. CONCLUSION: In our study, this test had comparable high sensitivity and high specificity and many advantages, such as being easy to perform and simple to interpret, and showing rapid results. If rapid influenza antigen tests are widely applied in the clinic, we can begin treatment more rapidly and reduce influenza complications and the abuse of antibiotics.