Volume 26, Number 8—August 2020
Synopsis
Investigation and Serologic Follow-Up of Contacts of an Early Confirmed Case-Patient with COVID-19, Washington, USA
, Brandi Freeman-Ponder1, Scott Lindquist, Christopher Spitters, Vance Kawakami, Jonathan W. Dyal, Shauna Clark, Hollianne Bruce, Jeffrey S. Duchin, Chas DeBolt, Sara Podczervinski, Marisa D’Angeli, Kristen Pettrone, Rachael Zacks, Grace Vahey, Michelle L. Holshue, Misty Lang, Rachel M. Burke, Melissa A. Rolfes, Mariel Marlow, Claire M. Midgley, Xiaoyan Lu, Stephen Lindstrom, Aron J. Hall, Alicia M. Fry, Natalie J. Thornburg, Susan I. Gerber, Satish K. Pillai, and Holly M. Biggs
Table 3
Demographic characteristics, underlying medical conditions, exposures, and SARS-CoV-2 testing among contacts of an early confirmed US COVID-19 case participating in the enhanced contact investigation, Washington, USA, 2020*
| Characteristic |
All contacts, N = 38 |
Community contacts |
Healthcare contacts | ||
|---|---|---|---|---|---|
| Office co-workers, n = 11 |
Waiting room contacts, n = 20 |
Healthcare personnel, n = 7† |
|||
| Age, y, median (range) |
45 (0–78) |
39 (24–62) |
53.5 (<1–78) |
36 (30–56) |
|
| Sex | |||||
| M | 21 (55) | 9 (82) | 9 (45) | 3 (43) | |
| F |
17 (45) |
2 (18) |
11 (55) |
4 (57) |
|
| Race | |||||
| White | 27 (71) | 2 (18) | 18 (90) | 7 (100) | |
| Asian | 8 (21) | 8 (73) | 0 | 0 | |
| Black | 0 | 0 | 0 | 0 | |
| Not specified |
3 (8) |
1 (9) |
2 (10) |
0 |
|
| Ethnicity | |||||
| Hispanic/Latino | 5 (13) | 0 | 3 (15) | 2 (29) | |
| Not Hispanic/Latino | 28 (74) | 10 (91) | 14 (70) | 4 (57) | |
| Not specified |
5 (13) |
1 (9) |
3 (15) |
1 (14) |
|
| Underlying medical conditions‡ | |||||
| None | 15 (39) | 8 (73) | 3 (15) | 4 (57) | |
| Asthma | 10 (26) | 3 (27) | 4 (20) | 3 (43) | |
| Diabetes mellitus, type 2 | 4 (11) | 0 | 4 (20) | 0 | |
| Hypertension | 7 (18) | 1 (9) | 6 (30) | 0 | |
| Coronary artery disease | 1 (3) | 0 | 1 (5) | 0 | |
| Immunosuppressive condition or therapy | 1 (3) | 0 | 1 (5) | 0 | |
| Pregnant or postpartum§ |
2 (5) |
0 |
1 (5) |
1 (14) |
|
| Exposure type¶ | |||||
| Face-to-face interaction | 16/18 (89) | 11 (100) | NA | 5 (71) | |
| Direct physical contact | 10/18 (56) | 6 (55) | NA | 4 (57) | |
| Physically within 6 feet | 16/18 (89) | 11 (100) | NA | 5 (71) | |
| Within 6 feet while case-patient was coughing or sneezing | 3/18 (17) | 0 | NA | 3 (43) | |
| Touched object handled by the case-patient | 13/18 (72) | 10 (91) | NA | 3 (43) | |
| In the same room | 14/18 (78) | 9 (82) | NA | 5 (71) | |
| Traveled in the same vehicle |
3/18 (17) |
3 (28) |
NA |
0 |
|
| Active monitoring | |||||
| Days from last exposure to start of active monitoring, median (range) | 4 (1–7) | 6 (5–7) | 4 (4–5) | 1 (1–1) | |
| Assessed as PUI during monitoring period† | 7 (18) | 2 (18) | 4 (20) | 1 (14) | |
| Days from last exposure until symptom onset among PUIs |
5 (1–11) |
6 (1–11) |
4.5 (3–11) |
6 (6–6) |
|
| Laboratory testing | |||||
| Any testing (rRT-PCR or serology) |
37 (97) |
11 (100) |
19 (95) |
7 (100) |
|
| Enhanced contact investigation: initial specimen collection within 14 d after last exposure to case-patient | |||||
| Contacts with respiratory specimens# | 36 (95) | 11 (100) | 19 (95) | 6 (86) | |
| Contacts with serum specimens | 28 (74) | 8 (73) | 14 (75) | 6 (86) | |
| Days from last exposure to initial specimen collection (respiratory and serum specimens) among asymptomatic contacts, median (range) |
11 (9–13) |
10 (10–11) |
11 (10–13) |
9 (9–11) |
|
| Enhanced contact investigation: follow-up serum, ≈6 weeks after last exposure to case-patient | |||||
| Contacts with follow-up serum specimens | 23 (61) | 9 (82) | 10 (50) | 4 (57) | |
| Days from last exposure to follow-up serum collection, median (range) | 46 (44–49) | 47 (46–47) | 46 (44–49) | 46 (45–47) | |
*Values are no. persons except as indicated. COVID-19, coronavirus disease; HCP, healthcare personnel; NA, not asked; PUI, person under investigation; rRT-PCR, real-time reverse transcription PCR.
†One HCP PUI was not available for interview and was not included in this table. Nasopharyngeal and oropharyngeal specimens were collected for this PUI testing, and were negative by rRT-PCR for SARS-CoV-2. No serum specimens were collected.
‡Some contacts had >1 underlying medical condition.
§Postpartum was defined as within 6 weeks after delivery.
¶Exposure types were not asked for waiting room contacts, as the case-patient was anonymous to the waiting room contacts.
#Included respiratory specimens obtained for PUI testing.
1These authors contributed equally to this article.