What is the difference between oropharyngeal swab and nasopharyngeal swab for nucleic acid testing

We all know that the two most common methods for nucleic acid testing are oropharyngeal swabs and nasopharyngeal swabs, so what is the difference between them?

Nasopharyngeal swabs and oropharyngeal swabs have different sampling methods and positions

The accuracy of the nasal and pharyngeal swabs for nucleic acid testing is usually about the same, but the main difference lies in the sampling method and sampling position differences. For nasal swab sampling, a nasal swab is used to detect secretions from the nasal cavity and the surface of the nasal mucosa, while a pharyngeal swab is used to detect pharyngeal specimens by passing through the oropharynx to determine whether the sampler is infected with the new coronavirus.

Do both oropharyngeal swabs and nasopharyngeal swabs need to be done?

No, you don’t need to do all of them. There is no difference between oropharyngeal swabs and nasopharyngeal swabs, if they are performed in a standardized manner, because they are both used to collect specimens from the pharynx. The difference is that one enters from the oral cavity. And the other one enters from the nasal cavity.

For the oropharyngeal swab the sampler can see the sampled position, but may bring nausea, vomiting and other reactions, and because the pharyngeal virus content is affected by diet, drinking and swallowing movements, so it will affect the positive detection rate of the oropharyngeal swab to some extent, but there is no need for both sampling methods at the same time.

Who is not suitable for nasopharyngeal swabs?

　　When collecting nasopharyngeal swab specimens, the swab will enter through the nasal cavity and cause less irritation to the mucosa if the operation is standardized, but because the sampling position in the pharynx is not visible and the main reliance is on the hand to feel the resistance, the technique required for the operator is higher and the tools used are more complex.

If the operation is not done properly, it will cause some irritation to the nasal mucosa, so it is not recommended for patients suffering from sinusitis and allergic rhinitis to do nasal swab to avoid damage to the nasal cavity.

How to overcome the discomfort of pharyngeal swab?

When collecting pharyngeal swab specimens, pharyngeal swab will cause some stimulation to the pharynx, and for some people with sensitive pharynx, they may have nausea and vomiting reaction.

When you feel discomfort in the throat after the collection, then you need to eat less spicy, stimulating, greasy food, drink more water, eat more vegetables and fruits, and arrange proper rest, and generally speaking, it does not take long to return to normal.