Proper procedure for collecting nasopharyngeal swabs.

1 . The sampler executes the swab (plastic rod wiper with polypropylene fiber head) with the right hand and presses the top of the subject's head with the left hand for fixation.

2 . Place the swab with the front end curved slightly downward into the anterior nostril and slowly penetrate backward along the base of the inferior nasal tract {slow movements are required due to the curved shape of the nasal tract. Do not be too strong in order not to cause trauma and bleeding}.

3 . After the front end of the swab reaches the posterior wall of the nasopharyngeal cavity (with the sensation of touching the wall), leave a little (about 3 seconds or so) of the swab, then gently rotate it for a week and slowly remove the swab.

4 . The other nostril of another plastic stick swab with a polypropylene fiber head can be collected in the same way, impregnating both of the above swabs in the same tube containing 3 ml of virus sampling solution, throwing off the end and tightening the cap.

5 . After packaging according to biosafety requirements, they should be sent to laboratories at all levels of the CDC for viral nucleic acid testing as soon as possible.

Precautions.

1 . Sampling subjects must be within 3 days of onset of disease and have a fever ≥ 38°C.

2 . Sampling solution should be put into cold storage (put ice row) and brought to the sampling site.

3 . If necessary, 2 nasopharyngeal swabs can be collected as parallel samples.

4 . The collected specimen must be immediately in the refrigerator of 4 (if there is no refrigerator at the site, it can be immediately put into the refrigerator) within 24 hours to be transported to the laboratory by refrigerator for examination (accompanied by a detailed sample registration form). If they cannot be delivered within 24 hours, they need to be stored below -70°C.

5 . In cases of pneumonia of unknown etiology, tracheal extracts can be collected.