Throat swab: What is it and how does it work?

Throat swab: What is it and how does it work?

A throat swab is a medical procedure that is used to analyze the pathogens of concern.

The current historical moment is bringing to media’s attention topics such as this, which we rarely hear about. In fact, these days, we often hear about the throat swab, which is used to diagnose the presence of viruses; currently, the attention is drawn to SARAS-CoV-2, the Coronavirus, which is all over newspapers, TV shows, and social networking sites. 

What is this test for?

How does it work? On which individuals should it be done on?

Let’s find answers to these questions.

What is a throat swab?

A throat swab is a test that involves the collection and analysis of a biological sample from inside the oral cavity, specifically the pharynx; it is from a small portion of the mucosa that is collected.

The throat swab is not to be confused, however, with other types of swabs intended for a different use: nasal, ocular, ear, rectal, vaginal etc.

By analyzing the material taken from the oral cavity, it is possible to detect the presence of specific infectious microorganisms, which can be as specific as the Coronavirus SARS-CoV-2, or other broad spectrum organisms.

When is it advisable to perform a throat swab test?

A throat swab is recommended and carried out by a doctor. The medical professional would usually suggest it in the case of persistent pain affecting the throat, together with the presence of cough. Furthermore, factors such as high temperature, muscle and joint pain, chills, loss of appetite, and general unwellness are all reasons why this test may be advisable.

Gaining more information around the nature of the microorganism infecting the host, in fact, makes it much easier to understand how to treat it and what drugs to use.

To list some examples of infectious microorganisms, the throat swab is commonly performed in the case of suspected presence of Group A Beta-hemolytic Streptococcus spp., Bordetella pertussis, Corynebacterium diphtheriae, and Staphylococcus aureus. Recently, the throat swab has become known because of its use to carry out microbiological tests for SARS-CoV-2.

How is a throat swab performed?

These are the steps in performing a throat swab:

The patient opens his/her mouth and the doctor uses a sterile tool called a “tongue depressor” or “spatula” to assist in lowering the tongue. To simply describe it, it looks a lot like a large ice cream stick. 

The sample can then be collected from the mucosa with a cotton swab which is similar to cotton buds; the healthcare worker must gently rub the tonsils and the posterior pharynx, where infectious microorganisms nest more abundantly, with the cotton swab.

At this stage, it is important to avoid touching the tongue and teeth, which can host other microorganisms that are not of interest.

The swab, with the sample of cells, is placed in a specific container filled with gel, which is also sterile, and kept at a 4 °C temperature and sent to an analysis laboratory. 

At this point, the sample undergoes a series of processes that determine the possible viral or bacterial load of the secretion.

This can be done in two ways: by reaction with a specific reagent for a specific pathogen, or by cell culture.

In the former case, the results are available within a few hours, in the latter, it will be necessary to wait a few days.

For Coronavirus SARS-CoV-2 in particular, it takes between 3 to 6 hours for the result

Beware of scams associated with home swabs

In this moment of great uncertainty and fear, there is no shortage of people trying to take advantage of the most defenseless population. This is currently happening in some regions of Italy, where fake Red Cross operators would call the elderly insisting to perform throat swabs at their home due to the Coronavirus emergency. Their real motive is to look for an excuse to break into defenseless people’s homes and take advantage of them.

Our recommendation is to get information only from official sources to minimize the risk of fraud and fake news.

Med4Care Marco De Nardin

Marco De Nardin, M.D., Anesthesiologist, and Critical Care Doctor




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