A nasopharyngeal swab is a device used for collecting a sample of nasal secretions from the back of the

nose A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passes th ...

and

throat In vertebrate anatomy, the throat is the front part of the neck, internally positioned in front of the vertebrae. It contains the pharynx and larynx. An important section of it is the epiglottis, separating the esophagus from the trachea (windpipe ...

. The sample is then analyzed for the presence of organisms or other clinical markers for disease. This diagnostic method is commonly used in suspected cases of

whooping cough Whooping cough, also known as pertussis or the 100-day cough, is a highly contagious bacterial disease. Initial symptoms are usually similar to those of the common cold with a runny nose, fever, and mild cough, but these are followed by two or ...

diphtheria Diphtheria is an infection caused by the bacterium '' Corynebacterium diphtheriae''. Most infections are asymptomatic or have a mild clinical course, but in some outbreaks more than 10% of those diagnosed with the disease may die. Signs and s ...

influenza Influenza, commonly known as "the flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms ...

, and various types of diseases caused by the

coronavirus Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the com ...

family of viruses, including

SARS Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the severe acute respiratory syndrome coronavirus (SARS-CoV or SARS-CoV-1), the first identified strain of the SARS coronavirus species, ''sever ...

MERS Middle East respiratory syndrome (MERS) is a viral respiratory infection caused by ''Middle East respiratory syndrome–related coronavirus'' (MERS-CoV). Symptoms may range from none, to mild, to severe. Typical symptoms include fever, cough, ...

, and

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was COVID-19 pandemic in Hubei, identified in Wuhan, China, in December ...

Procedure

To collect the sample, the swab is inserted in the

nostril A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbi ...

and gently or harshly (experience varies depending on the person doing the procedure.) moved forward into the

nasopharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struct ...

, a region of the pharynx that covers the roof of the mouth. The swab is then rotated for a specified period of time to collect secretions, then the swab is removed and placed into a sterile

viral transport media Viral transport medium (VTM) is a solution used to preserve virus specimens after collection so that they can be transported and analysed in a laboratory at a later time. Unless stored in an ultra low temperature freezer or in liquid nitrogen, ...

, which preserves the sample for the subsequent analysis.

Material composition of swab

Similar in concept to the

cotton swab Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus ''Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor perc ...

, a swab used for nasopharyngeal collection constitutes a narrow stick made of a short plastic rod that is covered, at one tip, with adsorbing material such as cotton, polyester, or flocked nylon. (Some swab handles have been made of nichrome or stainless steel wire.) The swab material used for a particular diagnostic application may vary based on the test type. Some research has shown that

flocked Flocking is the process of depositing many small fiber particles (called flock) onto a surface. It can also refer to the texture produced by the process, or to any material used primarily for its flocked surface. Flocking of an article can be per ...

swabs collect a larger volume of the sample material, when compared to fiber swabs.

Related methods

Slightly different but related is nasopharyngeal aspiration. Rather than depending on a physical swab to catch material from the nasopharynx, aspiration uses a

catheter In medicine, a catheter (/ˈkæθətər/) is a thin tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. Cath ...

that is attached to a syringe. As with the swab method, the catheter is placed into the nostril and gently advanced to the nasopharynx, where approximately one to three milliliters of saline are introduced, followed by immediate re-aspiration of the saline—along with cells and secretions—back into the syringe. This aspiration method is often used when 1. the patient is an infant or elderly and 2. when the method is indicated as effective for a test type.

Diagrams

File:Nose and nasal cavities.png, Diagram of the nasal cavity File:Diagnosis-image2.jpg, Nasopharyngeal aspiration File:Pertussis Testing Video- Collecting a Nasopharyngeal Aspirate Clinical Specimen.webm, Collecting nasopharyngeal aspirate File:Infektionsschutzzentrum im Rautenstrauch-Joest-Museum, Köln-6313 (cropped).jpg File:Prueba COVID.webm, Video of a nasopharyngeal swab test for COVID-19

References

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Procedure

Material composition of swab

Related methods

Diagrams

See also

References