Figure 1.

Different salivary samples. Posterior oropharyngeal saliva is the secretion produced when coughing or clearing one’s throat, and it belongs to the respiratory secretions, admixing secretions from both the upper (nasopharynx) and lower (bronchi, lungs) airways (number 1 in the circle). In contrast, oral saliva is produced by the salivary glands and does not belong to the group of respiratory specimens (number 2 in the circle). However, a clear distinction between these 2 kinds of samples is not feasible and does not fall within the aim of laboratory clinical diagnosis of Coronavirus Disease 2019. The saliva produced when coughing will contain oral saliva, while a small quantity of oropharyngeal secretions may be present in oral saliva.