The pharyngeal subdivision includes the nasopharynx, oropharynx, and laryngopharynx, and the mucosa of all three is continuous and all belong to the region of the upper respiratory tract.
The main difference is that the path of sampling is different; transoral sampling is oropharyngeal swab and transnasal sampling is nasopharyngeal swab.
What are the advantages and disadvantages of nasopharyngeal swabs and oropharyngeal swabs?
Nasopharyngeal swab
Advantages
1. It can be left in the pharynx for a longer period of time in order to obtain a more adequate amount of specimen, which is the reason why its positive rate is reported in the literature to be higher than that of oropharyngeal swabs.
2. The risk of exposure of the sampler is relatively lower: because the sampler can stand behind the patient's side during sampling, the patient can only expose the nostrils and the mask covers the mouth, so there is no need to look directly into the patient's mouth, and there is basically no gag reflex, and because the sampler is not directly in front of the patient, the risk of exposure is considerably lower and the sampler is relatively safe.
Disadvantages
Compared with oropharyngeal swab, it may be more difficult for patients to tolerate. If patients tolerate it well, they can basically take samples without anesthesia after skilled operation, but surface anesthesia and contraction of the nasal mucosa can be performed first when learning for the first time.
Oral swab
Advantages
Oropharyngeal swabs are more commonly used clinically because they can be performed with an open mouth and are relatively simple to perform.
Disadvantages
The risk of exposure to the sampler is higher, the operator often needs to be directly in front of the patient's mouth, and the patient is prone to irritating dry cough and vomiting during the collection process exposing the collector to virus-carrying aerosols.
