Table 2.

Advantages and disadvantages of tests to detect the presence of severe acute respiratory syndrome caused by coronavirus^11,17, 18, 19, 20, 21, 22, 23

Test	Use	Advantages	Disadvantages
Molecular test (RT-PCR, NAAT)	•Within 2 wk of symptom onset •To detect viral RNA •Within 2 wk of symptom onset •Asymptomatic screening •NP or OP swab for asymptomatic patients •Bilateral NP or nasal swab for symptomatic patients •Bronchoscopy (intubated patients only) if diagnosis uncertain	•Most Sn and Sp method to confirm acute infection	•Expensive •Requires specialized skills and equipment (must be run in a laboratory) •Results take 24–48 h
Antigen rapid detection tests	•Within 2 wk of symptom onset •To detect viral protein if molecular testing not available or rapid results needed •NP or OP swab	•Rapid results (15–30 min) •Can be done at point-of-care, including self-tests •Requires minimal training •Less expensive than molecular tests	•Less Sn than molecular tests •Variable quality, especially with self-tests •If test negative, must repeat sample for molecular testing
Antibody test	•More than 2 wk after symptom onset •To establish late or retrospective diagnosis if molecular and antigen tests negative •Primarily used in the inpatient setting or to identify antibody donors •Used in combination with molecular and antigen tests •Blood test	•Rapid antibody tests can provide results in 15–20 min	•Laboratory-based assays can take 24 h for results •May be nonspecific (false-positive result) •Does not distinguish between natural or vaccine-induced seropositivity •Not used for diagnosis of acute infection