Volume 16, Number 1—January 2010
Research
Epidemiology of Travel-associated Pandemic (H1N1) 2009 Infection in 116 Patients, Singapore
Table 2
Predictors of time to isolation for 116 patients with travel-associated pandemic (H1N1) 2009, Singapore, April 26–June 27, 2009*
Predictive factor | No. patients | Delay to isolation, mean no. days (95% CI)† | p value‡ |
---|---|---|---|
Port of embarkation | 0.718 | ||
Asian countries | 56 | 1.64 (1.32–1.96) | |
All other countries |
60 |
1.55 (1.20–1.91) |
|
Source of referral to TTSH | 0.015 | ||
Airport doctors | 15 | 0.76 (0.33–1.19) | |
Community doctors | 50 | 1.58 (1.28–1.88) | |
Self-referral |
51 |
1.85 (1.44–2.27) |
|
Met US-CDC ILI criteria§ | 0.426 | ||
No | 56 | 1.69 (1.31–2.08) | |
Yes |
60 |
1.50 (1.21–1.79) |
|
Met WHO ILI criteria¶ | 0.650 | ||
No | 65 | 1.64 (1.30–1.99) | |
Yes |
51 |
1.53 (1.21–1.86) |
|
Time of onset of symptoms | 0.664 | ||
Before embarkation | 29 | 1.78 (1.14–2.42) | |
While traveling | 17 | 1.49 (0.87–2.12) | |
After disembarkation |
70 |
1.54 (1.29–1.80) |
|
Duration of travel, h | 0.350 | ||
<3 | 22 | 1.96 (1.37–2.55) | |
3–5.9 | 34 | 1.39 (1.03–1.74) | |
6–14.9 | 36 | 1.69 (1.31–2.08) | |
>15 |
24 |
1.41 (0.74–2.08) |
|
Arrival at TTSH, by epidemiologic week# | 0.868 | ||
21 | 5 | 1.83 (0.50–3.15) | |
22 | 8 | 1.30 (0.44–2.16) | |
23 | 13 | 1.87(1.13–2.61) | |
24 | 41 | 1.61 (1.17–2.05) | |
25 | 49 | 1.53 (1.19–1.87) |
*CI, confidence interval; TTSH, Tan Tock Seng Hospital, Singapore; US CDC, US Centers for Disease Control and Prevention; ILI, influenza-like illness; WHO, World Health Organization.
†No. days from arrival to hospital examination in patients with onset before arrival and no. days from onset to hospital examination in patients with onset after arrival.
‡p value by t test for dichotomous variables and 1-way analysis of variance for multichotomous variables.
§Temperature >37.8°C plus cough or sore throat.
¶Temperature >38.0°C plus cough or sore throat.
#Week 21, May 24–30; week 22, May 30–June 6; week 23, June 7-13; week 24, June 14–20; week 25, June 21–27.