While different types of diagnostic tests may be used to detect coronavirus disease, a nasopharyngeal swab test is the most common. The test must be performed by a trained healthcare provider. If cell culture is collected in a wrong manner, the diagnosis obtained may be incorrect.
The World Health Organization (WHO) recommends that providers use a sterile dacron or rayon swab with a flexible, plastic shaft for deep nasal sampling. Cotton, calcium alginate swabs, or swabs with wooden sticks may contain such compounds that can inactivate some viruses and inhibit the diagnostic polymerase chain reaction (PCR). The following protocol describes the proper procedure for collecting a nasopharyngeal swab sample.
Figure 1. Image for the Surveillance of Vacine-Preventable Disease, 2015 (https://www.cdc.gov/pertussis/clinical/diagnostic-testing/specimen-collection.html#swab-testing)
While different types of diagnostic tests may be used to detect coronavirus disease, a nasopharyngeal swab test is the most common. A sterile dacron or rayon swab with a flexible plastic shaft should be used. Cotton, calcium alginate swabs, or swabs with wooden sticks may contain compounds that can inactivate some viruses and inhibit the diagnostic test.
Begin by escorting the patient into the examination area. Then explain the process to the patient and obtain consent to proceed. Open the swab package and remove the swab. Tilt the patient's head back to an approximate angle of 70 degrees, which will straighten the passage from the front of the nose to the nasal pharynx. Instruct the patient to close his or her eyes, then gently insert the swab along the nasal septum until resistance is felt. Rotate the swab several times for 10 to 15 seconds to collect the sample material.
Then remove the swab and insert the sample into a collection vial containing one to three milliliters of vial transport media. Break the swab handle at the marked break point and close the vial. Label the vial with the collection date, onset date, patient age and sex, specimen type, unique identifiers, and any other pertinent patient information. Repeat the same procedure with the other nostril. Then follow the manufacturer's instructions to store the sample and transport it to an FDA-approved diagnostic laboratory.
While different types of diagnostic tests may be used to detect coronavirus disease, a nasopharyngeal swab test is the most common. A sterile dacron or rayon swab with a flexible plastic shaft should be used. Cotton, calcium alginate swabs, or swabs with wooden sticks may contain compounds that can inactivate some viruses and inhibit the diagnostic test.
Begin by escorting the patient into the examination area. Then explain the process to the patient and obtain consent to proceed. Open the swab package and remove the swab. Tilt the patient’s head back to an approximate angle of 70 degrees, which will straighten the passage from the front of the nose to the nasal pharynx. Instruct the patient to close his or her eyes, then gently insert the swab along the nasal septum until resistance is felt. Rotate the swab several times for 10 to 15 seconds to collect the sample material.
Then remove the swab and insert the sample into a collection vial containing one to three milliliters of vial transport media. Break the swab handle at the marked break point and close the vial. Label the vial with the collection date, onset date, patient age and sex, specimen type, unique identifiers, and any other pertinent patient information. Repeat the same procedure with the other nostril. Then follow the manufacturer’s instructions to store the sample and transport it to an FDA-approved diagnostic laboratory.