COVID-19 Diagnostics: Performing a Nasopharyngealand Oropharyngeal SwabIt is essential to follow proper infectioncontrol measures when samples are collectedfrom patients with a suspected Coronavirusinfection. Among other things, the examinershould wear an N95 respirator mask, gown,protective goggles, and gloves. To save resources,we will refrain from using each of these itemsin this video and instead only show the technicaldetails of sample collection. Let’s begin with the nasopharyngeal swab. The patient should be alert and cooperative. Allow them to first blow their nose. The patientshould sit in a relaxed and comfortable positionduring the sample collection process. Tiltthe patient’s head back slightly and supportit with your non-dominant hand. If necessary,lean the patient’s head against a wall tominimize jerky movements. Stand slightly offsetfrom the patient to avoid the risk of contaminationin case of sudden cough or sneeze. Be sure to advise the patient of potentialdiscomfort during sample collection, and letthe patient know that they are welcome toclose their eyes. Sample collection should only be completedusing sterile swabs made from artificial cottonwith flexible plastic shafts. Calcium alginate swabs or swabs with woodenshafts must not be used. These materials caninactivate viral particles or inhibit PCRtests. Furthermore, wooden shafts are morelikely to cause patient injury. Hold the swab like a pen between the thumb,index, and middle fingers. Maintain a loosegrip that allows the swab to accommodate anyresistance encountered during sample collection,to reduce the risk of injury. Avoid using the following hand position duringsample collection. Let’s begin with the nasopharyngeal swab,the preferred method of sample collection. Start by inserting the swab horizontally intothe left or right nostril. Carefully advancethe swab while maintaining a course that isclose to both the septum and the floor ofthe nose, parallel to the palate. Do not advance the swab upwards, but insteadstraight back until resistance is felt asthe swab reaches the posterior nasopharynx. When collecting samples from an adult patient,this corresponds to a travel distance of approximately5-6 centimeters or 2 inches. The swab shouldreach a depth equal to half the distance betweenthe nostrils and the outer opening of theear. Leave the swab at this depth for a few secondswhile gently wiping the wall by twisting theswab shaft. Slowly and gently remove the swab. Immediately insert the swab into the samplecollection tube, which may contain 2-3 mLof viral transport media. If a nasopharyngeal swab cannot be collectedfor any reason, an oropharyngeal sample canalso be collected through the mouth. Again,inform the patient that the smear will feeluncomfortable for a short time and may triggera gag reflex. Ask the patient to open their mouth wide,protrude their tongue forward, and say “Ah. ”Depress the patient’s tongue using a tonguedepressor. Gently insert the swab into theoral cavity without touching the lips, teeth,tongue, hard palate, or soft palate. Thesesurfaces should be avoided as they are oftencolonized by a wide range of microbes. Collect the sample from the back wall of thethroat. Twist the swab shaft gently but thoroughly,sampling the oropharyngeal wall. Just as with the nasopharyngeal swab, theoropharyngeal swab should now be placed intothe sample collection tube and sent to thelaboratory as quickly as possible.