The demographic and clinical characteristics of 66 patients were presented in Table 1. The male-to-female ratio was 44:22, and the two most common initial symptoms of SARS-CoV-2 infection were fever (77.3%) and cough (74.2%). As the results shown, five, 50 and 11 patients were diagnosed as mild, moderate and severe cases, respectively. No critical case was determined according to the criteria. Compared to the non-severe cases (mild/moderate), the severe patients were more likely to be older (62.6 ± 15.1 vs 46.9 ± 13.3 years. P = 0.001). However, no significant difference in the length of hospital stay between the severe and non-severe patients (18.6 ± 8.0 vs 15.9 ± 4.0 days, P = 0.094). In addition, 38.2% of non-severe patients and 63.6% of severe patients coexisted with various underlying diseases, respectively (= 2.432, P = 0.182).
Table 1 Demographic characteristics and initial clinical signs/symptoms of 66 COVID-19 patients
Symptoms/signs
|
Mean±SD/cases (%)
|
Sex
|
|
Male (no., %)
|
44 (66.7)
|
Female (no., %)
|
22 (33.3)
|
Age (years)
|
|
Non-severe cases
|
46.9 ± 13.3
|
Severe cases
|
62.6 ± 15.1
|
Clinical classification (no., %)
|
|
Mild
|
5 (7.6)
|
Ordinary
|
50 (75.7)
|
Severe
|
11 (16.7)
|
Initial symptoms (no., %)
|
|
Fever
|
51 (77.3)
|
Cough
|
49 (74.2)
|
Fatigue
|
20 (30.3)
|
Myalgia
|
16 (24.2)
|
Asthma
|
15 (22.7)
|
Chest tightness
|
14 (21.2)
|
Sore throat
|
11 (16.7)
|
Diarrhea
|
3 (4.5)
|
Vomiting
|
2 (3.0)
|
Headache
|
1 (1.5)
|
Dyspnea
|
1 (1.5)
|
Underlying disease (no., %)
|
|
Non-severe
|
21 (38.2)
|
Severe
|
7 (63.6)
|
Length of hospital stay (days)
|
|
Non-severe
|
15.9 ± 4.0
|
Severe
|
18.6 ± 8.0
|
Non-severe patients including mild and moderate cases
The medical records and epidemiological history of each case revealed that there were eight cases potentially exposed to one single patient (Case 2) (Fig. 1). Case 2, a 48-year-old man, was the only patient of this cluster that had been in Wuhan, China. When he returned from Wuhan on Jan 15, 2020, he had a cough but without treatment. On Jan 25, 2020, his father (Case 5) and mother (Case 6) developed fever (the highest temperature was 38.8°C), cough and asthma. On Jan 18, 2020, Case 2 went to have a bath in a public bathhouse. Case 28, who took a bath together with Case 2, developed fever on Jan 25, 2020 and was demonstrated positive for the SARS-CoV-2 on Feb 3, 2020. Subsequently, the persons who closely contacted with Case 28, including his father (Case 27), father-in-law (Case 18), wife (Case 25) and two colleagues (Case 24 and 31) were diagnosed as COVID-19 between Feb 1 and Feb 3, 2020. Among nine patients, Case 2 and 6 showed severe symptoms and needed ticosteroids treatment, mechanical ventilation, or admission to ICU. The remaining seven patients were determined as mild or moderate SARS-CoV-2 infection. As of Feb 28, 2020, all cases have fully recovered and been discharged from the hospital.
Abnormalities on chest radiography suggesting pneumonia were occurred in all included patients. As the results shown, lesions were found in one lobe in two patients (mild: 1; moderate: 1), two lobes in eight patients (mild: 3; moderate: 5), three lobes in four patients (mild: 1; moderate: 3) and four lobes in 52 patients (moderate: 41; severe: 11). The duration from disease onset to the time when abnormalities on the chest radiography were first noted was 1-18 days (median 7 days).
The laboratory data on admission were listed in Table 2. The patients with severe COVID-19 were more likely to be with higher neutrophil counts, lower lymphocyte counts, and elevated levels of AST, LDH and CRP. During the hospitalization (Table 3), the peak levels of AST, LDH and CRP in severe COVID-19 patients were much higher than those in mild and moderate cases. However, lower lymphocyte counts increased the severity rate for SARS-CoV-2 infection.
Table 2 Laboratory characteristic of mild, moderate and severe hospitalized patients with SARS-CoV-2 infection on admission
Laboratory indexes
|
Clinical symptoms
|
P
|
Mild
|
Moderate
|
Severe
|
Leukocyte counts (´109/L)
|
4.6 ± 1.7
|
4.8 ± 1.6
|
6.5 ± 4.3
|
0.342
|
Lymphocyte counts (´109/L)
|
1.6 ± 0.9
|
1.3 ± 0.5
|
0.5 ± 0.2
|
<0.001
|
Neutrophil counts (´109/L)
|
2.6 ± 0.9
|
3.1 ± 1.3
|
5.7 ± 4.2
|
0.013
|
Platelet counts (´109/L)
|
172.0 ± 42.7
|
153.6 ± 42.6
|
149.5 ± 57.7
|
0.640
|
CRP levels (mg/L)
|
6.4 ± 6.9
|
31.2 ± 34.2
|
75.3 ± 73.2
|
0.006
|
ALT levels (U/L)
|
28.0 ± 8.5
|
31.7 ± 18.7
|
41.5 ± 28.7
|
0.322
|
AST levels (U/L)
|
24.4 ± 8.8
|
26.4 ± 12.1
|
38.6 ± 17.4
|
0.018
|
LDH levels (U/L)
|
183.6 ± 40.4
|
221.7 ± 65.8
|
306.9 ± 104.4
|
0.013
|
CK levels (U/L)
|
120.4 ± 82.0
|
84.4 ± 70.9
|
97.7 ± 72.3
|
0.520
|
CRP: C-reactive protein; ALT: alanine aminotransferase; AST: aspartate aminotransferase; LDH: lactate dehydrogenase; CK: creatine kinase
Table 3 Laboratory characteristics of mild, moderate and severe patients with SARS-CoV-2 infection during hospitalization
Laboratory indexes
|
Clinical symptoms
|
P
|
Mild
|
Moderate
|
Severe
|
Lowest leukocyte counts (´109/L)
|
4.3 ± 1.3
|
4.0 ± 1.0
|
3.4 ± 1.2
|
0.170
|
Lowest lymphocyte count (´109/L)
|
1.2 ± 0.5
|
1.0 ± 0.4
|
0.4 ± 0.2
|
<0.001
|
Lowest neutrophil count (´109/L)
|
2.5 ± 0.8
|
2.3 ± 0.7
|
2.3 ± 0.7
|
0.757
|
Lowest platelet counts (´109/L)
|
163.8 ± 49.6
|
142.0 ± 40.3
|
116.6 ± 59.1
|
0.110
|
Peak CRP level (mg/L)
|
19.1 ± 20.8
|
44.8 ± 43.0
|
162.5 ± 72.4
|
<0.001
|
Peak ALT level (U/L)
|
39.0 ± 21.2
|
54.3 ± 37.2
|
80.7 ± 49.8
|
0.074
|
Peak AST level (U/L)
|
26.4 ± 10.3
|
33.5 ± 15.9
|
66.1 ± 38.6
|
0.005
|
Peak LDH level (U/L)
|
189.6 ± 40.8
|
262.1 ± 101.2
|
426.1 ± 234.0
|
0.002
|
Peak CK level (U/L)
|
139.4 ± 76.2
|
116.7 ± 110.0
|
204.6 ± 206.5
|
0.129
|
CRP: C-reactive protein; ALT: alanine aminotransferase; AST: aspartate aminotransferase; LDH: lactate dehydrogenase; CK: creatine kinase
As the results shown in Table 4, multivariate logistic analysis suggested that higher initial (on admission) and peak (during hospitalization) counts of lymphocyte were inversely associated with the severe SARS-CoV-2 infection (both OR: 0.01 every 1´109/L decrease). However, the elevated initial neutrophil counts (OR: 1.63 every 1´109/L increase), initial and peak levels of LDH (OR: 1.02 and 1.01 every 1 U/L increase), peak levels of CRP (OR: 1.03 every 1 mg/L increase), AST (OR: 1.06 every 1 U/L increase) and ALT (OR: 1.02 every 1 U/L increase) were significantly associated with COVID-19 severity.
Table 4 Multivariate logistic regression analysis of laboratory indexes for severe COVID-19 in hospitalized patients
Laboratory indexes
|
OR(95% CI)a
|
P a
|
OR(95%CI)b
|
P b
|
Initial leukocyte counts (every 1× 109/L)
|
1.32 (0.98-1.77)
|
0.064
|
1.29 (0.97-1.72)
|
0.085
|
Initial lymphocyte count (every 1× 109/L)
|
0.01 (0.001-0.02)
|
0.001
|
0.01 (0.001-0.05)
|
0.002
|
Initial neutrophil count (every 1× 109/L)
|
1.82 (1.17-2.84)
|
0.009
|
1.63 (1.04-2.55)
|
0.033
|
Initial platelet count (every 1 × 109/L)
|
1.00 (0.98-1.01)
|
0.694
|
1.00 (0.98-1.01)
|
0.812
|
Initial CRP level (every 1 mg/L)
|
1.02 (1.00-1.04)
|
0.013
|
1.02 (0.99-1.04)
|
0.077
|
Initial ALT level (every 1 U/L)
|
1.02 (0.99-1.05)
|
0.157
|
1.03 (0.99-1.06)
|
0.147
|
Initial AST level (every 1 U/L)
|
1.06 (1.01-1.11)
|
0.015
|
1.05 (0.99-1.11)
|
0.104
|
Initial LDH level (every 1 U/L)
|
1.01 (1.00-1.02)
|
0.003
|
1.02 (1.00-1.03)
|
0.006
|
Initial CK level (every 1 U/L)
|
1.00 (0.99-1.01)
|
0.669
|
1.00 (0.99-1.01)
|
0.960
|
Lowest leukocyte counts (every 1 × 109/L)
|
0.54 (0.27-1.08)
|
0.082
|
0.56 (0.27-1.19)
|
0.134
|
Lowest lymphocyte count (every 1 × 109/L)
|
0.01 (0.001-0.01)
|
0.001
|
0.01 (0.001-0.03)
|
0.002
|
Lowest neutrophil count (every 1 × 109/L)
|
0.83 (0.32-2.16)
|
0.695
|
0.91 (0.31-2.63)
|
0.856
|
Lowest platelet count (every 1 × 109/L)
|
0.99 (0.97-1.00)
|
0.073
|
0.99 (0.97-1.01)
|
0.208
|
Peak CRP level (every 1 mg/L)
|
1.03 (1.02-1.05)
|
<0.001
|
1.03 (1.01-1.06)
|
0.002
|
Peak ALT level (every 1 U/L)
|
1.02 (1.00-1.03)
|
0.047
|
1.02 (1.00-1.04)
|
0.016
|
Peak AST level (every 1 U/L)
|
1.06 (1.02-1.10)
|
0.003
|
1.06 (1.02-1.11)
|
0.005
|
Peak LDH level (every 1 U/L)
|
1.01 (1.00-1.01)
|
0.006
|
1.01 (1.00-1.01)
|
0.023
|
Peak CK level (every 1 U/L)
|
1.00 (0.99-1.01)
|
0.069
|
1.00 (0.99-1.01)
|
0.160
|
CRP: C-reactive protein; ALT: alanine aminotransferase; AST: aspartate aminotransferase; LDH: lactate dehydrogenase; CK: creatine kinase
aUnadjusted model.
bAdjusted for age and gender.