The adjective “nasopharyngeal” refers to the nose (naso) and throat (pharyngeal), describing where to insert the swab and how far back the swab needs to go in order to collect an adequate specimen for testing for a viral respiratory pathogen. 

A thin, flexible wire with a rayon or dacron tip is bent to follow the curve of the nasopharynx and inserted into the nostril until the back of the throat, which is generally the distance from the nostril to the ear. As it is gently pulled out, the swab is rotated in order to capture the specimen.

So far, the CDC is recommending that 2 nasopharyngeal swabs be obtained for the suspected influenza virus. The second specimen is then taken from the other nostril. Once both samples are obtained, they are placed in a vial containing  a special transport medium and sent off for testing.

Currently, preliminary testing is done at a local lab and if the virus comes back as Influenza B, then the second swab does not need to be forwarded to the State lab. If however it is positive for Influenza A, then the second specimen is forwarded to the State lab and/or then on to the CDC for further genetic testing to determine if it is the H1N1 virus.

Preliminary results can be obtained in hours but the final results do take several days.