Volume 27, Number 11—November 2021
Research
Seroprevalence of SARS-CoV-2–Specific Antibodies among Quarantined Close Contacts of COVID-19 Patients, Faroe Islands, 2020
, Marnar Fríðheim Kristiansen, Halla Weihe Reinert, Jógvan Páll Fjallsbak, Debes Hammershaimb Christiansen, Shahin Gaini, Bjarni á Steig, Lars Fodgaard Møller, Marin Strøm, and Pál Weihe
Table 1
Demographic and clinical characteristics of 584 quarantined close contacts of coronavirus disease patients in study of seroprevalence of SARS-CoV-2–specific antibodies, Faroe Islands, 2020*
| Characteristic | Close contacts |
p value† | ||
|---|---|---|---|---|
| Total | Seronegative | Seropositive | ||
| Total |
584 (100.0) |
552 (100.0) |
32 (100.0) |
|
| Sex | 0.8 | |||
| F | 339 (58.0) | 321 (58.2) | 18 (56.3) | |
| M |
245 (42.0) |
231 (41.8) |
14 (43.8) |
|
| Mean age, y (SD) [range] |
36.5 (20.2) [0.2–83.8] |
37.0 (19.9) [0.2–81.7] |
28.1 (24.0) [1.4–83.8] |
0.02 |
| Age group, y | <0.01 | |||
| 0–9 | 69 (11.8) | 61 (11.1) | 8 (25.0) | |
| 10–17 | 68 (11.6) | 62 (11.2) | 6 (18.8) | |
| 18–34 | 134 (22.9) | 125 (22.6) | 9 (28.1) | |
| 35–49 | 131 (22.4) | 128 (23.2) | 3 (9.4) | |
| 50–66 | 150 (25.7) | 148 (26.8) | 2 (6.3) | |
| >67 |
32 (5.5) |
28 (5.1) |
4 (12.5) |
|
| Smoking status‡ | 0.1 | |||
| Active | 93 (16.7) | 92 (17.4) | 1 (3.6) | |
| Occasional | 41 (7.3) | 40 (7.5) | 1 (3.6) | |
| Former | 127 (22.8) | 121 (22.8) | 6 (21.4) | |
| Never |
297 (53.2) |
277 (52.3) |
20 (71.4) |
|
| Daily medication use§ | 0.6 | |||
| Yes | 145 (27.8) | 137 (27.6) | 8 (32.0) | |
| No |
376 (72.2) |
359 (72.4) |
17 (68.0) |
|
| Self-reported chronic diseases‡ | 0.06 | |||
| Yes | 278 (49.8) | 268 (50.6) | 10 (35.7) | |
| No |
280 (50.2) |
262 (49.4) |
18 (64.3) |
|
| Had PCR during quarantine¶ | 0.2 | |||
| Yes | 263 (48.3) | 249 (47.8) | 21 (65.6) | |
| No |
281 (51.7) |
272 (52.2) |
11 (34.4) |
|
| Had symptoms during quarantine# | 0.7 | |||
| Yes | 116 (21.4) | 112 (21.6) | 14 (43.8) | |
| No | 345 (63.5) | 327 (63.1) | 18 (56.3) | |
| Not sure |
82 (15.1) |
79 (15.3) |
0 |
|
| Had other family members in quarantine** | 0.2 | |||
| No | 120 (21.8) | 118 (22.5) | 2 (7.4) | |
| Yes, together | 373 (67.7) | 352 (67.2) | 21 (77.8) | |
| Yes, separated |
58 (10.5) |
54 (10.3) |
4 (14.8) |
|
| Type of contact†† | <0.01 | |||
| Household | 145 (28.9) | 125 (26.5) | 20 (64.5) | |
| Workplace | 184 (36.7) | 179 (38.0) | 5 (16.1) | |
| Other | 173 (34.5) | 167 (35.5) | 6 (19.4) | |
*Values are no. (%) except as indicated. SARS-CoV-2, severe acute respiratory syndrome coronavirus 2. †p values determined by χ2 test for categorical variables or analysis of variance for continuous variables. ‡Questionnaire data missing for 26 quarantined close contacts, including 4 seropositive contacts. §Questionnaire data missing for 63 quarantined close contacts, including 7 seropositive contacts. ¶Questionnaire data missing for 40 quarantined close contacts, including 9 seropositive contacts. However, all seropositive patients were asked about PCR; as a result, values do not add up. #Questionnaire data missing for 41 quarantined close contacts, including 7 seropositive contacts. However, all seropositive patients were asked about symptoms; as a result, values do not add up. **Questionnaire data missing for 33 quarantined close contacts, including 5 seropositive contacts. ††Questionnaire data missing for 82 quarantined close contacts, including 1 seropositive contact.