Results
We recommend to perform NPS after elevation of the tip of the nose in
order to reduce the risk of contamination from the nasal vestibule
(Figure 1), and to let it flow over the floor of the nasal cavity in
parallel to the hard palate in order to reach the nasopharynx. Then the
tip of the swab should be left in place for few seconds, and then
rotated in order to achieve the largest absorption of nasopharyngeal
secretions. Regards OPS, gentle anterior tongue depression should be
used to avoid swab contamination from the oral cavity during collection
of secretions from the posterior pharyngeal wall (Figure 2).
With regards to self-collection of saliva samples, a throat-cleaning
manoeuvre would be useful to retrieve infected secretions both
descending from the nasopharynx and moving up from the tracheo-bronchial
district.