Table 2. Detection of Sudden Acute Respiratory Syndrome Coronavirus 2 by Sampling Method and Days from Symptom Onset to Study Sample Collection in Stanford, California, March 2020.

Participant	Time from self-reported symptom onset, d	Self-collected nasal swab	Physician-collected nasal swab	Physician-collected oropharyngeal swab
1	18	Detected	Detected	Detected
2	10	Not detected	Not detected	Not detected
3	8	Detected	Detected	Detected
4	13	Detected	Detected	Detected
5	22	Not detected	Not detected	Not detected
6	9	Not detected	Not detected	Not detected
7	NAa	Not detected	Not detected	Not detected
8	26	Not detected	Not detected	Not detected
9	28	Detected	Detected	Detected
10	9	Detected	Detected	Detected
11	8	Detected	Detected	Detected
12b	NAa	Detected	Not detected	Not detected
13	16	Not detected	Not detected	Not detected
14	14	Not detected	Not detected	Not detected
15	NAa	Not detected	Not detected	Not detected
16	10	Not detected	Not detected	Not detected
17	37	Not detected	Not detected	Not detected
18	24	Not detected	Not detected	Not detected
19	NAa	Detected	Detected	Detected
20	16	Not detected	Not detected	Not detected
21	9	Not detected	Not detected	Not detected
22	NAa	Not detected	Not detected	Not detected
23	21	Not detected	Not detected	Not detected
24	15	Not detected	Not detected	Not detected
25	23	Not detected	Not detected	Not detected
26	10	Detected	Detected	Detected
27c	4	Detected	Detected	Detected
28	NAa	Not detected	Not detected	Not detected
29	10	Detected	Detected	Detected
30	NAa	Detected	Detected	Detected

Abbreviation: NA, not applicable.

^aSymptom onset was not recorded in the electronic medical record for participants 7, 12, 15, 19, 22, 28, and 30.

^bParticipant 12 presented with discordant results, with a positive result for the self-collected nasal sample but negative results from both physician-collected samples.

^cParticipant 27 was asymptomatic but had been exposed to sudden acute respiratory syndrome coronavirus 2 by close contact 4 days before the study swab was obtained.