The key difference between nasopharyngeal and oropharyngeal swab is that a nasopharyngeal swab is a clinical test sample taken from the upper part of the pharynx, while an oropharyngeal swab is a clinical test sample taken from the middle part of the pharynx.
A swab is a medical device used for the collection of clinical samples from the human body. It also allows for the transport and preservation of the sample. These swabs are specially utilized for the collection of microbiological samples. They are usually considered invasive medical devices for temporary use. Moreover, these swabs are used in the pre-analytical phase. When testing for viruses, the clinical sample is taken from the human body using kits that consist of a swab and a tube with transport media. Nasopharyngeal and oropharyngeal swabs are two types of swabs designed for collecting a clinical test sample.
CONTENTS
1. Overview and Key Difference
2. What is a Nasopharyngeal Swab
3. What is an Oropharyngeal Swab
4. Similarities – Nasopharyngeal and Oropharyngeal Swab
5. Nasopharyngeal vs Oropharyngeal Swab in Tabular Form
6. Summary – Nasopharyngeal vs Oropharyngeal Swab
What is a Nasopharyngeal Swab?
A nasopharyngeal swab is a clinical test sample collected from the upper part of the pharynx. It is a way of collecting a clinical sample of respiratory secretions. The sample is then analyzed for the presence of microorganisms. It can also be used for analyzing other clinical markers for diseases. This diagnostic swab method is useful in testing suspected cases of whooping cough, diphtheria, influenza, and various types of viral diseases due to coronavirus family including MERS, SARS, and COVID-19.
Figure 01: Nasopharyngeal Swab
To collect a test sample, the swab should be inserted into the nostrils and gently moved forward into the nasopharynx. The nasopharynx is 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 the secretions. Then the swab is removed and placed into a tube containing a sterile viral transport medium. This preserves the clinical sample for the subsequent analysis. Moreover, obtaining a more accurate diagnosis is more likely when sampling with nasopharyngeal swabs when compared to other methods. Therefore, it is the standard swab for reliable testing.
What is an Oropharyngeal Swab?
An oropharyngeal swab is a swab used to collect a clinical test sample from the middle part of the pharynx. Oropharyngeal swabs are designed to collect samples from the back of the throat. Oropharyngeal swab sampling is easier to perform. The swab is directed towards the rear wall of the oropharynx. Then the swab is rotated for a few minutes before removal. After taking the sample, it is necessary to insert the oropharyngeal swab in the tube containing a sterile viral transport medium.
Figure 02: Oropharyngeal Swab
Oropharyngeal swabs are more comfortable, and a safer method for patients who have certain critical conditions such as chronic nose bleeds and nasal polyps. However, obtaining an accurate diagnosis is less likely when sampling with the oropharyngeal swabs.
What are the Similarities Between Nasopharyngeal and Oropharyngeal Swab?
- Nasopharyngeal and oropharyngeal swabs are two types of swabs used for collecting a clinical test sample.
- These swabs facilitate the collection of respiratory secretions.
- Both swabs are manufactured with a tube containing a sterile viral transport medium.
- Both swabs are available for viral and bacterial pathogens collection from the human respiratory system and can be used across a variety of diagnostic testing platforms.
- They are comparatively cheap and easy to use.
What is the Difference Between Nasopharyngeal and Oropharyngeal Swab?
A nasopharyngeal swab is a swab designed for collecting a clinical test sample from the upper part of the pharynx, while an oropharyngeal swab is a swab designed for collecting a clinical test sample from the middle part of the pharynx. So, this is the key difference between nasopharyngeal and oropharyngeal swab. Furthermore, it is more likely to obtain a more accurate diagnosis when sampling with the nasopharyngeal swabs, but it is less likely to obtain an accurate diagnosis when sampling with the oropharyngeal swabs.
The below infographic lists the differences between nasopharyngeal and oropharyngeal swab in tabular form for side by side comparison.
Summary – Nasopharyngeal vs Oropharyngeal Swab
Nasopharyngeal and oropharyngeal swabs are two types of swabs used for collecting clinical test samples from patients for various diagnoses. Nasopharyngeal swab collects a clinical test sample from the upper part of the pharynx, while oropharyngeal swab collects a clinical test sample from the middle part of the pharynx. Thus, this is the key difference between nasopharyngeal and oropharyngeal swab.
Reference:
1. Cuffari, Benedette. “What Is a NASOPHARYNGEAL Swab?” News, 24 Feb. 2021.
Image Courtesy:
1. “Nasopharyngeal swab test” By Luis Prado via the Noun Project
2. “Throat Culture” By BruceBlaus – Own work (CC BY-SA 4.0) via Commons Wikimedia