Comparing Methods: Anterior Nasal Swab Sampling vs Nasopharyngeal Swab Sampling

Are you heading in for a flu or COVID-19 test? Common Covid-19 test uses oropharyngeal sampling method, but in specific cases, the nasal sampling method is also used. Nasal samples have a higher virus content and a higher detection positive rate than oropharyngeal samples. Let’s discuss the differences between anterior nasal swab sampling and nasopharyngeal swab sampling as well as the two different types of sample swabs.

Anterior Nasal Swab

The anterior nasal method is done with a swab to collect specimen from the nasal membrane. Insert the anterior nasal swab into the nostril about 0.5-0.75 inch deep and rotate for 10-15 seconds while touching the sides of the nasal wall.

while touching the sides of the nasal wall is rotated for 10-15 seconds in one nostril, then with the same swab, collected the same way in the other nostril. Because this method is less invasive, it is usually more comfortable for the patient—and also the method used when self-testing.

Swabs used for nasal sampling typically have a medium-sized tip made of an absorbent substance, most regularly flocked fibers, spun polyester, or medical-grade foam. Typically, ABS is used for the nasal swab handle.

Nasopharyngeal Swab

The nasopharyngeal collection method collects a sample from the nasopharynx (upper part of the throat behind the nose). The healthcare practitioner gently supports the patient’s head while using nasopharyngeal swab as it slowly and carefully insert rearward into the nostril to prevent scratching and bleeding. Gently rotate and slowly withdraw the swab once it has touched the posterior wall of the nasopharyngeal. It might not be necessary to take a sample from both nostrils if the tip of the swab is fully saturated with the specimen. This method tends to be less comfortable for the patient and should only be performed by a healthcare practitioner.

A swab used for nasopharyngeal is one designed with a miniature tip made of an nylon flocked material and one with a thin, flexible handle usually made of soft plastic or wire.

It should be noted that nasopharyngeal swab sampling should be avoided in patients with moderate allergic rhinitis, nasal malformations (such as a curved nasal septum), recent nasal bleeding symptoms, within three months of a recent nasal surgery, blood diseases, long-term anticoagulant medications, and other relevant medical histories and risk factors.