Among 450 COVID19 patients, 422 answered the call and agreed to be interviewed (response rate:93.77%). Among responders, 257 cases were male (60.90%) and 165(39.10%) were female (sex ratio = 1.55 male). Most patients were in upper-middle education level (n = 148, 33.77%). The prevalence of smoking was 11.84%(n = 50). One hundred sixty-five patients (39.09%) reported the history of being in condition with a risk of exposure to COVID-19, such as attending a party or event (n = 85, 51.1%), use of public transportation (n = 55, 33.33%), history of referral to a hospital of health care center (n = 11, 6.6%) and keep going to work (n = 14, 8.4%), within 14 days before the onset of their symptoms. Out of 262(62.09%) patients with recorded co-morbidities, the most prevalent comorbidities were hypertension (n = 111, 42.36%), followed by diabetes (n = 93, 35.49%), hyperlipidemia (n = 76; 29.00%) and history of cardiovascular disease (49; 18.70%). The mean ± sd of staying at home (home isolation) after discharge was 25.85 ± 23.78 days (Table 1).
Table 1
Demographic, contact history, and co-morbidities of COVID-19 patients participated in this study
Total(n = 319)
|
|
Sex(male) *
|
Male
|
257(60.90)
|
Female
|
165(39.10)
|
Education level
|
Illiterate or elementary
|
98(23.31)
|
Under intermediate
|
83(19.84)
|
Upper intermediate
|
140(32.71)
|
Academic
|
101(23.96)
|
Age (years)
|
< 40
|
94(22.38)
|
40–50
|
73(17.38)
|
50–60
|
100(23.81)
|
60–70
|
89(21.91)
|
70<
|
64(15.24)
|
Co-morbidities (n = 262, 62.08)
|
HTN
|
111(42.36)
|
Diabetes
|
93(35.49)
|
Hyperlipidemia
|
76(29.00)
|
Cardiovascular
|
49(18.70)
|
Cancer
|
34 (12.97)
|
Renal
|
17(6.48)
|
Asthma
|
16(6.10)
|
Intestinal
|
14(5.34)
|
Liver
|
11(4.19)
|
COPD
|
6(2.29)
|
CVA
|
3(1.32)
|
Hospital duration(days)
|
< 3
|
215(50.94)
|
3–7
|
141(33.41)
|
7–10
|
37(8.76)
|
10<
|
28(6.63)
|
History of potential exposure within 14 days before symptoms
|
Yes
|
165(39.09)
|
No
|
220(52.13)
|
|
Not remembered
|
37(8.76)
|
Having symptoms after discharge,
|
Yes
|
252(59.71)
|
No
|
170(40.28)
|
Days did not go out after discharge (weeks)
|
< 2
|
111(26.30)
|
2–3
|
142(33.65)
|
3–5
|
116(27.49)
|
5<
|
53(12.56)
|
Visited after discharge
|
Yes
|
220(52.13)
|
No
|
147(34.83)
|
Not remembered
|
55(13.03)
|
Apartment/house
|
Apartment
|
232(54.97)
|
House
|
52(12.31)
|
Not answered
|
138 (32.70)
|
Return to job
|
Yes
|
85(27.24)
|
No
|
227(72.76)
|
Quality of isolation/
|
Good
|
255(60.42)
|
Bad
|
79(18.72)
|
Not answered
|
88(20.8)
|
House density
|
Low
|
138(32.70)
|
Moderate
|
218(51.66)
|
High
|
66(15.64)
|
Within three weeks since the discharge, 41(9.71%) participants had at least one new case in their close contacts. Among others, 307(72.74%) stated that there was no new case in their close contacts. The rest of the patients, 74(17.53%) did not know whether there was any new case in their closes or not. Of those who had new cases in their close contacts, 30 (73.17%) patients stated that there was one new case, eight patients (19.51%) stated that there were two new cases, and three patients (7.31%) stated that there were three new cases in their close contacts. In sum, there were 55 symptomatic new cases which can potentially have got the infection from 41 discharged patients within 3 weeks of their time of discharge. The majority of new cases were male (n = 23; 59.25%) and the average age was 39.35 ± 14.73.
Those patient who had at least one new case of covid-19 in their close contacts (n = 41) were compared to participants who stated that there was no any new case in their contacts (n = 307) (control to case ratio 7.48:1). The mean (sd) of cases and controls were 54.19(15.90) and 53.72(15.98), respectively (p = 0.73). Nineteen patients (46.34%) with new cases in their close contacts were female, while it was 34.85% (n = 107) for the rest [male to female; OR(CI): 0.61(0.32–1.19); P:0.15]. The direction of having a high level of education (academic) was in reverse with the probability of potential infectivity (not significant) [low to high; OR(CI): 1.11 (0.47–2.6); P: 0.80.8].
There was no statistically significant difference between smoking habits regarding the risk of potential transmission (n = 6, 12.5% versus n = 34, 11.45% respectively); [OR(CI): 1.10 (0.43–2.79); P: 0.83]. However, there was a significant association between having a co-morbidity in patients with the odds of getting infected in their close contacts [OR(CI): 2.45 (1.05–4.72); P: 0.03].
The density of inhabitant per houses rooms and the quality of isolation had significant associations with potential transmission in close contacts [high density to moderate density; OR(CI): 2.44 (1.06–5.61); P: 0.03], [ bad condition to good condition; OR(CI): 2.31 (1.17–4.59); P:0 .01], respectively. Regarding the result of multivariable analysis, there was no significant simultaneous confounding effect by age, sex, and education level, for observed associations and the results of the univariate analysis did not change significantly in multivariate analysis(Table 2).
Table 2
Crude and age-sex- education-adjusted associations for potential determinant factors and the incidence of the symptomatic COVID-19 in close contacts of COVID-19 recovered patients, within three weeks after discharge.
|
|
New case in closed contacts (n;%)
|
Crude OR(95% CI)
|
P
|
Adjusted odds ratio(CI)
|
P
|
potential determinant factors of being a source of infection
|
YES
|
NO
|
Hospital duration
|
More than 3days
|
20(48.78)
|
156(50.98)
|
.91(.47–1.75)
|
.79
|
.85(.43–1.69)
|
.48
|
Less than 3days(reference)
|
21(51.22)
|
150(49.02)
|
Having symptoms after discharge
|
Yes
|
26(63.41)
|
200(65.15)
|
.92(.47–1.82)
|
.82
|
.85(.43–1.69)
|
.48
|
no(reference)
|
15(36.59)
|
107(34.85)
|
Visit health centers after discharge
|
Yes
|
11(27.50)
|
120(40.40)
|
.55(.26–1.16)
|
.11
|
.53(.25–1.11)
|
.09
|
no(reference)
|
29(72.50)
|
177(59.60)
|
return to job
|
Yes
|
9(25.71)
|
75(27.88)
|
.89(.40–1.99)
|
.78
|
1.03 (.42 − 2.51)
|
.93
|
no(reference)
|
26(74.29)
|
194(72.12)
|
Days not to go out
|
More than 3wks
|
16(39.02)
|
142(46.25)
|
.74(.38 -1.44)
|
.38
|
.76(.38–1.52)
|
.44
|
Less than 3weeks (reference)
|
25(60.98)
|
165(53.75)
|
home density
|
low
|
15(36.59)
|
103(33.55)
|
1.57(.72 -3.39)
|
.25
|
1.65 (.75 -3.63)
|
.20
|
high
|
12(29.27)
|
53(17.26)
|
2.44 (1.06–5.61)
|
.03
|
2.79(1.19–6.54)
|
.01
|
moderate(reference)
|
14(34.15)
|
151(49.19)
|
-
|
-
|
|
|
Quality of isolation
|
bad
|
17(41.46)
|
203(76.60)
|
2.31 (1.17–4.59)
|
.01
|
2.19 (1.09– 4.39)
|
.02
|
good(reference)
|
24(58.54)
|
62(23.40)
|