Volume 10, Number 2—February 2004
THEME ISSUE
2004 SARS Edition
SARS Transmission
Probable Secondary Infections in Households of SARS Patients in Hong Kong
Joseph T.F. Lau*
, Mason Lau*, Jean H. Kim*, Eric Wong*, Hi-Yi Tsui*, Thomas Tsang†, and Tze Wai Wong‡
, Mason Lau*, Jean H. Kim*, Eric Wong*, Hi-Yi Tsui*, Thomas Tsang†, and Tze Wai Wong‡
Table 1
Univariate association between various risk factors and Household Member Attack Rates (HMAR)
| Risk factor | % attack rate |
Odds ratio (95% CI) | Chi-square p value | |
|---|---|---|---|---|
| Case |
Control |
|||
| (n = 131) | (n = 2,139) | |||
| Sexa |
||||
| Male |
46.6 |
48.3 |
1.00 |
0.701 |
| Female |
53.4 |
51.7 |
1.07 (0.75 to 1.53) |
|
| Age (y)b |
||||
| 18–30 |
46.6 |
46.9 |
1.00 |
0.287 |
| 31–40 |
15.3 |
15.3 |
1.17 (0.68 to 2.01) |
|
| 41–50 |
16.2 |
16.3 |
1.04 (0.60 to 1.81) |
|
| 51–60 |
10.9 |
10.7 |
1.58 (0.90 to 2.76) |
|
| >61 |
11.1 |
10.8 |
1.65 (0.95 to 2.86) |
|
| Type of Index Person (IP) |
||||
| Hospital care workers |
7.6 |
33.5 |
1.00 |
<0.001c |
| Amoy Gardens Block E residents |
10.7 |
2.8 |
16.99 (7.23 to 39.90) |
|
| Amoy Gardens other Block residents |
15.3 |
10.6 |
6.31 (2.91 to 13.67) |
|
| Other community members |
66.4 |
53.2 |
5.48 (2.83 to 10.61) |
|
| Date of IP’s fever onsetd |
||||
| Before March 25 |
51.9 |
34.2 |
1.00 |
<0.001 |
| On or after March 25 |
48.1 |
65.8 |
0.48 (0.34 to 0.69) |
|
| Duration IP stayed home between fever onset and hospitalization (d)e |
||||
| <2 |
31.3 |
51.0 |
1.00 |
<0.001 |
| 3–5 |
32.1 |
30.3 |
1.72 (1.11 to 2.68) |
|
| >6 |
36.6 |
18.8 |
3.18 (2.07 to 4.90) |
|
| IP visited by a family member during hospitalization? |
||||
| No |
73.3 |
87.9 |
1.00 |
<0.001 |
| Yes |
26.7 |
12.1 |
2.65 (1.76 to 3.98) |
|
| Mask use during hospital visits by a household memberf |
||||
| Not visited by any household member |
75.0 |
88.6 |
1.00 |
<0.0013 |
| Visited, both with mask on |
6.3 |
4.0 |
1.87 (0.88 to 3.96) |
|
| Visited, one with mask on |
5.5 |
3.6 |
1.78 (0.80 to 3.96) |
|
| Visited, both without mask on |
13.3 |
3.8 |
4.16 (2.37 to 7.30) |
|
| Whether caretaker of IP |
||||
| No |
64.9 |
82.0 |
1.00 |
<0.001 |
| Yes |
35.1 |
18.0 |
2.47 (1.70 to 3.60) |
|
| Whether shared room and bed with IPg |
||||
| Never |
59.7 |
81.3 |
1.00 |
<0.001 |
| Sharing room |
8.9 |
7.3 |
1.66 (0.86 to 3.19) |
|
| Sharing room and bed |
31.5 |
11.4 |
3.74 (2.48 to 5.64) |
|
| Frequency of dining together with IPh |
||||
| Never |
37.0 |
60.2 |
1.00 |
<0.001 |
| <5 |
21.8 |
18.7 |
1.90 (1.15 to 3.12) |
|
| 5–10 |
14.3 |
9.7 |
2.40 (1.35 to 4.29) |
|
| >10 |
26.9 |
11.4 |
3.82 (2.38 to 6.15) |
|
| Frequency of close contact with IP (within 1 m)i |
||||
| Never |
22.5 |
48.4 |
1.00 |
<0.001 |
| Seldom |
15.0 |
14.7 |
2.19 (1.19 to 4.02) |
|
| Occasionally |
24.2 |
16.4 |
3.17 (1.85 to 5.42) |
|
| Frequent |
38.3 |
20.5 |
4.03 (2.47 to 6.56) |
|
| Frequency coughed at by IP (within 1 meter) j |
||||
| Never |
77.6 |
90.3 |
1.00 |
<0.0013 |
| Seldom |
6.5 |
4.2 |
1.81 (0.81 to 4.03) |
|
| Occasionally |
10.3 |
2.8 |
4.29 (2.17 to 8.48) |
|
| Frequent | 5.6 | 2.6 | 2.47 (1.03 to 5.90) | |
aInformation on 31 controls missing.
bInformation on 7 cases and 160 controls missing .
cChi-square test exact p value.
dInformation on 3 controls missing.
eInformation on 6 controls missing.
fInformation on 3 cases 18 controls missing.
gInformation on 7 cases and 24 controls missing.
hInformation on 12 cases and 51 controls missing.
iInformation on 13 cases and 37 controls missing.
jInformation on 24 cases and 98 controls missing.
Page created: February 03, 2011
Page updated: February 03, 2011
Page reviewed: February 03, 2011
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