Epidemiological characteristics
By 15 March 2020, clinical data were collected on 758 patients quarantined at rehabilitation post stations in Huangpi, Wuhan, Hubei province with laboratory confirmed COVID-19 infection. Twenty one (2.77%) of the patients were aged <10 years, 19 (2.51%) were aged 10-19 years, 76 (10.02%) were aged 20-29 years, 148 (19.53%) were aged 30-39 years, 153 (20.18%) were aged 40-49 years, 158 (20.84%) were aged 50-59 years, 120 (15.83%) were aged 60-69 years, 50 (6.60%) were aged 70-79 years, 13 (1.72%) were aged 80 years and older. The median age was 48 years (interquartile range 35-58 years), and the mean (SD) age was 46.61 (16.82) years (Table 1). The 396 patients (51.40%) were male. All of 758 patients were confirmed diagnosis cases, and had 2 consecutively negative RT-PCR test results separated by at least 1 day before hospital discharge.
Of them, 59 patients (59/758, 7.78%) were detected positive RT-PCR test results when quarantined at rehabilitation post stations. Of the 59 patients with recurrent RT-PCR results for COVID-19 after hospital discharge, One (1.70%) of the patients were aged <10 years, 1 (1.70%) were aged 10-19 years, 9 (15.25%) were aged 20-29 years, 10 (16.95%) were aged 30-39 years, 5 (8.47%) were aged 40-49 years, 13 (22.03%) were aged 50-59 years, 13 (22.03%) were aged 60-69 years, 4 (15.83%) were aged 70-79 years, 3 (5.09%) were aged 80 years and older. The median age was 52 years (interquartile range 35-65 years), and the mean (SD) age was 49.61 (16.64) years (Table 1). The 29 patients (49.15%) were male.
Table1.Clinical characters of Patients recovered from Coronavirus Disease 2019(COVID-19).
Measure
|
(as of March 15, 2020)
|
RT-PCR Results
|
|
|
|
Total
|
Positive
|
Negative
|
Difference*
|
(95% CI)
|
P value
|
(n)
|
(%)
|
(n)
|
(%)
|
(n)
|
(%)
|
758
|
100.00%
|
59
|
7.78%
|
699
|
92.22%
|
Age (years)
|
Minimum to Maximum
|
1-92
|
/
|
8-87
|
/
|
1-92
|
/
|
-3.257 ± 2.279
|
-7.731 to 1.217
|
0.1534
|
Median (interquartile)
|
48
|
(35-58)
|
52
|
(35-65)
|
47
|
(35-57)
|
Mean±SD (95% CI)
|
46.61±16.82
|
(45.41-47.81)
|
49.61±18.64
|
(44.75-54.47)
|
46.35±16.65
|
(45.12-47.59)
|
≥80 years
|
13
|
1.72%
|
3
|
5.09%
|
10
|
1.43%
|
70-79years
|
50
|
6.60%
|
4
|
6.78%
|
46
|
6.58%
|
60-69years
|
120
|
15.83%
|
13
|
22.03%
|
107
|
15.31%
|
50-59years
|
158
|
20.84%
|
13
|
22.03%
|
145
|
20.73%
|
40-49years
|
153
|
20.18%
|
5
|
8.47%
|
148
|
21.17%
|
30-39years
|
148
|
19.53%
|
10
|
16.95%
|
138
|
19.75%
|
20-29years
|
76
|
10.02%
|
9
|
15.25%
|
67
|
9.59%
|
10-19years
|
19
|
2.51%
|
1
|
1.70%
|
18
|
2.58%
|
<10years
|
21
|
2.77%
|
1
|
1.70%
|
20
|
2.86%
|
Gender
|
Male
|
396
|
51.40%
|
29
|
49.15%
|
367
|
52.50%
|
-0.03351 ± 0.06780
|
-0.1666 to 0.09958
|
0.62
|
Female
|
362
|
48.60%
|
30
|
50.85%
|
332
|
47.50%
|
Severity of disease
|
Mild
|
229
|
25.12%
|
16
|
27.12%
|
213
|
30.47%
|
0.008608 ± 0.08114
|
-0.1507 to 0.1679
|
0.92
|
Moderate
|
465
|
67.63%
|
40
|
67.80%
|
425
|
60.80%
|
Severe
|
60
|
6.67%
|
3
|
5.08%
|
57
|
8.16%
|
Critical
|
4
|
0.58%
|
0
|
0.00%
|
4
|
0.57%
|
Time from disease onset to diagnosis (days)
|
Minimum to Maximum (days)
|
1-61
|
/
|
1-33
|
/
|
1-61
|
/
|
1.940 ± 1.054
|
-0.1289 to 4.008
|
0.07
|
Median (interquartile) (days)
|
8
|
(3-13)
|
6
|
(1-11)
|
8
|
(3-14)
|
Mean±SD (95% CI) (days)
|
9.31±7.78
|
(8.76-9.87)
|
7.53±7.15
|
(5.66-9.39)
|
9.47±7.82
|
(8.88-10.05)
|
≤1 week
|
374
|
49.34%
|
34
|
57.63%
|
340
|
48.64%
|
≤2 weeks
|
218
|
28.76%
|
17
|
28.81%
|
201
|
28.76%
|
≤3 weeks
|
107
|
14.11%
|
5
|
8.47%
|
102
|
14.59%
|
≤4 weeks
|
39
|
5.15%
|
1
|
1.70%
|
38
|
5.44%
|
≤5 weeks
|
19
|
2.51%
|
2
|
3.39%
|
17
|
2.43%
|
≥8 weeks
|
1
|
0.13%
|
0
|
0.00%
|
1
|
0.14%
|
Abbreviations:IQR,interquartile range;*Difference between (Negative - Positive) ± SEM;
Clinical features
The severity of disease was mild to critical for 758 patients, while mild to severe for 59 patients with recurrent positive result of RT-PCR for SARS-Cov-2. Among these 758 patients, there were 229 (25.12%) cases judged as moderate, 465 (67.63%) cases judged as moderate, 60 (6.67%) judged as severe, and 4 (0.58%) cases judged as critical, which was graded according to the guideline of PC-NCP [1] (Table 1). While of those, 16 of the 59 patients (27.12%) were judged as mild, 40 (67.80%) judged as moderate, 3 (5.08%) judged as severe, but 0 (0.00%) cases were judged as critical (Table 1).
For all 758 patients, The time range from onset of symptoms to first hospitalized ranged were 1-61 days. The median time from onset of symptoms to first hospital admission was 8 (3-13) days. And the mean (SD) was from onset of symptoms to first hospital admission was 9.31 (7.78) days. For 59 patients with recurrent positive result of RT-PCR for SARS-Cov-2, the time range from onset of symptoms to first hospitalized ranged were 1-33 days. The median time from onset of symptoms to first hospital admission was 6 (1-11) days. And the mean (SD) was from onset of symptoms to first hospital admission was 7.53 (7.15) days. To March 15, 2020, the patients remain asymptomatic and no more infections were detected (Table 1).
Recurrent positive results of RT-PCR for SARS-Cov-2
Of the 59 patients with recurrent positive results of RT-PCR for SARS-Cov-2, the time from onset of symptoms to last time of positive results of RT-PCR for SARS-Cov-2 was ranged from 14 to 61 days, The median time from onset of symptoms to first hospital admission were 30 (23-39) days, and the mean (SD) of those were 31.78 (12.17) days, respectively. In addition, the time from diagnosis to last time of positive results of RT-PCR for SARS-Cov-2 was ranged from 13 to 48 days, The median time and the mean (SD) from onset of symptoms to first hospital admission were 24 (20-29) days, and 25.53 (7.857) days, respectively. Last, the time from quarantined to last time of positive results of RT-PCR was ranged from 1 to 19 days, The median time and the mean (SD) from onset of symptoms to first hospital admission were 8 (4-11) days, and 7.746 (4.13) days, respectively (Table 2).
Table2.Characteristics of 59 recovered Patients From COVID-19 With positive results of RT-PCR.
|
Positive RT-PCR Results
|
From disease onset
|
From Diagnosis
|
From hospital dischage
|
First time
|
Last time
|
Last time
|
Last time
|
Median(IQR)
|
1 (-2-7)
|
30 (23-39)
|
24 (20-29)
|
8 (4-11)
|
Minimum to Maximum
|
-4-31
|
14-61
|
13-48
|
1-19
|
Mean±SD
|
4.153±7.701
|
31.78±12.17
|
25.53±7.857
|
7.746±4.13
|
95% CI of mean
|
2.146-6.159
|
28.61-34.95
|
23.48-27.54
|
6.67-8.822
|
Last (weeks)≧1 week (n)
|
/
|
/
|
/
|
23
|
≧2 weeks (n)
|
/
|
/
|
1
|
33
|
≧3 weeks (n)
|
/
|
11
|
15
|
3
|
≧4 weeks (n)
|
/
|
15
|
25
|
/
|
≧5 weeks (n)
|
/
|
9
|
12
|
/
|
≧6 weeks (n)
|
/
|
15
|
5
|
/
|
≧7 weeks (n)
|
/
|
3
|
3
|
/
|
≧8 weeks (n)
|
/
|
2
|
/
|
/
|
≧9 weeks (n)
|
/
|
4
|
/
|
/
|
Abbreviations:IQR,interquartile range;
Serological RDT test for the patients with recurrent positive results of RT-PCR for SARS-Cov-2
The IgG and IgM antibody for SARS-CoV-2 were tested in 50 of 59 COVID-19 patients with recurrent positive results of RT-PCR for SARS-Cov-2. 45 of 50 (90.00%) patients had positive results of IgG antibody for SARS-CoV-2, while 4 of 50 patients (8.00%) had positive results of dual IgM/IgG antibody for SARS-CoV-2.
No risk factor in the patients with recurrent RT-PCR results for SARS-CoV-2 infection were found
There were no significant difference between age, gender, severity, time between disease onset to diagnosis. Binary logistic regression analysis showed that not age, gender, severity of disease, nor time last from onset to hospitalized was the risk factor for recurrent RT-PCR in quarantined patients with COVID-19. Based on the current data, no risk factor in the patients with recurrent RT-PCR results for SARS-CoV-2 infection were found.