Table 1.
Characteristics of Nursing Home Individuals With Repeated Positive SARS-CoV-2 Test Specimens, 4 US Jurisdictions, July 2020–November 2021
| Characteristic | Total | High RNA Viral Load (Ct < 30) |
Low RNA Viral Load (Ct ≥30 or Negative at Retesting) a | P Value b |
|---|---|---|---|---|
| No. (%) | No. (%) | No. (%) | ||
| 64 | 10 (16) | 54 (84) | ||
| Age, median y [IQR] | 67 [51–80] | 62 [47–79] | 68 [53–80] | .56 |
| Days from initial infection to repeated positive test, median [IQR] | 194 [124–251] | 122 [103–229] | 201 [139–254] | .13 |
| Nursing home role, no. (%) | .16 | |||
| Resident | 40 (63) | 4 (40) | 36 (67) | |
| HCP | 24 (38) | 6 (60) | 18 (33) | |
| Testing between initial and repeated positive test, no. (%) | ||||
| At least 2 negative SARS-CoV-2 RT-PCR or antigen test result | 30 (47) | 6 (60) | 24 (44) | .49 |
| Had a negative SARS-CoV-2 RT-PCR or antigen test result 14 d prior to repeated positive test | 32 (50) | 7 (70) | 25 (46) | .30 |
| Days from most recent SARS-CoV-2 RT-PCR or antigen test to repeated positive test result, median [IQR] | 7 [6–14] | 4 [4–7] | 8 [6–14] | .05 |
| Symptom status at time of repeated positive test, no. (%) c | <.01 | |||
| Asymptomatic | 31 (84) | 5 (50) | 26 (96) | |
| Symptomatic | 6 (16) | 5 (50) | 1 (4) | |
| Known or suspected COVID-19 exposure in nursing home outbreak at repeated positive episode, no. (%) d,e | .18 | |||
| Yes | 46 (79) | 9 (100) | 37 (76) | |
| No | 12 (21) | 0 (0) | 12 (24) | |
| Symptomatic or confirmed or suspected COVID-19 exposure, no. (%) f | .57 | |||
| Yes | 48 (91) | 10 (100) | 38 (88) | |
| No | 5 (9) | 0 (0) | 5 (12) | |
| SARS-CoV-2 viral sequence of repeated positive specimen, no. (%) g,h | … | |||
| B.1.1.186 | … | 1 (10) | … | |
| B.1.234 | … | 2 (20) | … | |
| B.1.296 | … | 1 (10) | … | |
| B.1.2 | … | 3 (30) | … | |
| B.1.1369 | … | 1 (10) | … | |
| B.1.1.434 | … | 1 (10) | … | |
| B.1.1.207 | … | 1 (10) | … | |
Note. Ct, cycle threshold value; HCP, healthcare personnel.
37 specimens had an undetectable SARS-CoV-2 RNA when retested.
Categories were compared for statistical significance by Wilcoxon signed-rank test or χ2 test when indicated.
n=37. Symptom status at time of repeated positive test is unknown for 27 individuals (0 with Ct < 30 and 27 with Ct ≥ 30).
n=58. Confirmed COVID-19 exposure is unknown for 58 individuals (5 with Ct <30 and 53 with Ct ≥ 30).
n=58. Suspected COVID-19 exposure during a nursing home outbreak at the time of repeated positive test is unknown for 6 individuals (1 with Ct < 30 and 5 with Ct ≥ 30).
n=53. Unknown exposure status for 11 individuals (11 with Ct ≥ 30).
No specimens had genetic sequences matching variants of interest or concern per SARS-CoV-2 variant classifications and definitions as of the update on August 26, 2021. 9
n=10. SARS-CoV-2 sequencing was performing for specimens with Ct < 30 only.