An Appropriate Lower Respiratory Tract Specimen Is Essential for Diagnosis of Middle East Respiratory Syndrome (MERS)

Lee, Jae Hoon; Lee, Chang-Seop; Lee, Heung-Bum

To obtain an accurate diagnosis, the circumstances in the early phase of MERS-CoV infection should be considered and at least two repeated diagnostic tests during the late incubation period should be considered for patients with less severity but persistent symptoms. The nationwide pneumonia census has been conducted to identify hidden MERS-CoV infections. However, inadequate sputum specimens must have resulted in false negatives. For accurate surveying, appropriate specimens should have been obtained by collecting sputum from the lungs or bronchi and not saliva. In suspicious patients who are unable to produce sputum for examination, aerosol administration of a hypertonic saline solution may be used to increase the flow of secretions and stimulate coughing. However, during the procedure of induced specimen collection, clinicians must consider the high risk of contamination of the surroundings because the procedure would create a large amount of aerosols and increase the risk of transmitting the virus to other individuals. The optimum time for collection of a sputum specimen is in the early morning before eating or drinking. At this time secretions accumulated in the bronchi through the night are more readily available.