Vol.99 No.9 contentsPRACTICA OTO-RHINO-LARYNGOLOGICA
Vol. 99 No. 9 September 2006
Clinical Usefulness of Nasal Mucus Specimen
for Rapid Influenza Antigen Test
Yoshio Umeda
(Akasaka Sanno Clinic)
During the 2004-2005 influenza season, a clinical study was conducted to evaluate the utility of nasal mucus collected by nose blowing as a specimen for the rapid influenza antigen test. In this study, nasal swab specimens and nasal mucus specimens were respectively collected from 136 patients who were suspected of having influenza infection. The nasal specimens were collected by existing standard methods and nasal mucus specimens were collected by the method that patients themselves blew their own noses. Then, both specimens were tested with a rapid influenza antigen detection kit (QuickVue rapid SP influ) and the results were compared. These results were also compared with the results of a culture test, which was performed as a gold standard.
Out of 40 influenza patients (type A: 9; and type B: 31) who were diagnosed by the culture test, 7 nasal swab specimens were A positive (sensitivity: 77.8％) and 13 were B positive (sensitivity: 41.9％) and 7 nasal mucus specimens were A positive (sensitivity: 77.8％) and 18 were B positive (sensitivity: 58.1％) with the rapid test. On the other hand, out of 96 influenza negative patients, all specimens of both types showed negative results (specificity: 100％) with the rapid test.
These results indicate that nasal mucus specimens collected by patients blowing their own nose have an equal or superior performance (sensitivity and specificity) to existing nasal swab specimens for the influenza antigen rapid test. Considering the easier and safer sampling practice of the nasal mucus specimen, we concluded that nasal mucus specimens collected by nose blowing have a clinical usefulness in the rapid influenza antigen test.
Key words:
clinical usefulness, nasal mucus specimen, rapid influenza antigen test