To the Editor:
To diagnose airborne infectious diseases such as coronavirus disease 2019 (COVID-19) or influenza, health care workers often need to collect respiratory specimens. The most common methods for respiratory specimen collections for severe acute respiratory syndrome coronavirus 2 and other airborne infectious pathogens include nasopharyngeal and oropharyngeal swabs or wash in ambulatory patients and lower respiratory specimens in patients with more severe respiratory disease.1 The upper respiratory specimens are more widely used than lower ones. All of these aerosol-generating procedures may increase the chance for health care workers to be infected.2 In previous studies, nasopharyngeal swab showed a higher positive rate than oropharyngeal swab and may be more applicable at this stage of the COVID-19 outbreak.3
In the COVID-19 pandemic, obtaining a nasopharyngeal swab specimen is common for patients with suspected COVID-19. Numerous photographs and videos demonstrating the procedure can be seen in both public social media and academic texts, including journals. However, under such a procedure, the patient whom the operator is facing is often depicted as having the mask taken off, which increases the risk of transmitting infective droplets or aerosols to the operator. Additionally, the insertion of a nasopharyngeal swab may trigger cough, gagging, or vomiting, generating even larger amounts of droplets or aerosols and thus increasing the risk of cross infection.
Strategies should be adopted to provide safer conditions for health care workers during the collection of nasopharyngeal swab samples. We emphasize and remind that the patient’s mouth should be covered with a mask during the collecting process. The patient is therefore required to pull down the mask to show only the nostrils while the mouth remains fully covered by the mask (Figure ). The benefit of this act is supported by the study, which demonstrates that covering the mouth with a cloth results in a decrease in the production of oral fluid droplets.4 Consequently, infective droplets or aerosols from the patient’s mouth are effectively reduced.
Figure.
Obtaining the nasopharyngeal swab specimen for a patient wearing a mask. During collection of the specimen, the patient is required to pull down the mask to show only the nostrils while the mouth remains fully covered by the mask. By doing so, infective droplets or aerosols from the patient’s mouth are effectively reduced.
Footnotes
Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article as per ICMJE conflict of interest guidelines (see www.icmje.org). The authors have stated that no such relationships exist.
References
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