Table 2.
Characteristics of Testing Instances by SARS-CoV-2 Result
| Positive | Overalla | Percent Positivity (95% CIb), % | |
|---|---|---|---|
| (n = 265) | (n = 29 783) | ||
| Any symptoms | 161 | 11 116 | 1.4 (1.2–1.7) |
| Attended large indoor gathering | 57 | 6996 | 0.8 (0.6–1.1) |
| Close contact with known positive | 92 | 3877 | 2.4 (1.9–2.9) |
| Baseline test | 35 | 5700 | 0.6 (0.4–0.9) |
| Outbreak test | 83 | 5257 | 1.6 (1.3–2) |
| Holiday test | 3 | 1244 | 0.2 (0–0.7) |
| Walk-in (no invite) | 18 | 1788 | 1.0 (0.6–1.6) |
| Risk tier | |||
| Tier 1 | 220 | 19 239 | 1.1 (1–1.3) |
| Tier 2 | 12 | 4291 | 0.3 (0.1–0.5) |
| Tier 3 | 33 | 6253 | 0.5 (0.4–0.7) |
| Affiliationc | |||
| Student | 240 | 23 802 | 1.0 (0.9–1.1) |
| Staff | 19 | 4417 | 0.4 (0.3–0.7) |
| Faculty | 4 | 1467 | 0.3 (0.1–0.7) |
| Age group | |||
| 13–17 y | 2 | 153 | 1.3 (0.2–4.6) |
| 18–49 y | 254 | 27 783 | 0.9 (0.8–1) |
| 50–64 y | 8 | 1548 | 0.5 (0.2–1) |
| 65+ y | 1 | 299 | 0.3 (0–1.8) |
| Sex assigned at birth | |||
| Female | 180 | 19 234 | 0.9 (0.8–1.1) |
| Male | 84 | 10 474 | 0.8 (0.6–1) |
| House members | |||
| Lives alone | 16 | 2708 | 0.6 (0.3–1) |
| 2 people | 63 | 8051 | 0.8 (0.6–1) |
| 3–5 people | 34 | 7468 | 0.5 (0.3–0.6) |
| 6+ people | 152 | 11 556 | 1.3 (1.1–1.5) |
| UW Greek member | 176 | 12 045 | 1.5 (1.3–1.7) |
| Race | |||
| American Indian or Alaska Native | 0 | 144 | 0.0 (0–2.5) |
| Asian | 32 | 4672 | 0.7 (0.5–1) |
| Black or African American | 2 | 460 | 0.4 (0.1–1.6) |
| Native Hawaiian or other Pacific Islander | 0 | 59 | 0.0 (0–6.1) |
| White | 191 | 20 464 | 0.9 (0.8–1.1) |
| Multiple races | 26 | 2808 | 0.9 (0.6–1.4) |
| Other | 10 | 707 | 1.4 (0.7–2.6) |
| Latinx/Hispanic | 35 | 2000 | 1.8 (1.2–2.4) |
| Housing type | |||
| Apartment (off campus) | 32 | 7403 | 0.4 (0.3–0.6) |
| Dormitory/residence hall (on campus) | 43 | 3507 | 1.2 (0.9–1.6) |
| House/condo/townhouse (off campus) | 62 | 10 433 | 0.6 (0.5–0.8) |
| Permanent supportive/transitional housing (off campus) | 0 | 6 | 0.0 (0–45.9) |
| Homeless shelter (off campus) | 0 | 5 | 0.0 (0–52.2) |
| UW Greek chapter house (off campus) | 104 | 6145 | 1.7 (1.4–2) |
| UW Greek live out (off campus) | 24 | 2168 | 1.1 (0.7–1.6) |
| Other | 0 | 116 | 0.0 (0–3.1) |
| Overall | 265 | 29 783 | 0.9 (0.8–1) |
Abbreviations: SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; UW, University of Washington.
aOverall includes 60 samples that were never tested.
bConfidence intervals were generated using the Clopper-Pearson exact method.
cEighty-six “other” and 15 “volunteer” affiliations.