Sample collection and preparation
Eighty-three nasopharyngeal (NP) and an oropharyngeal swabs (OP) were
obtained by trained health staff at the isolation units. Based on
recommendation from Center for Disease Control and Prevention (CDC)
(CDC, 2020) and to maximize sensitivity
and to limit the use of test resources, the two NP and OP swabs taken
from one participant were admixed in a 3-ml tube containing viral
transport medium (VTM, Ismailia free zone, Egypt. Ref: 1/V T01.001.0001)
and stored at -80 °C until further analyses.