Table 2.

Risk factors associated with post-primary, opposed to primary, active dengue immune status

Risk factor	Post-primary
	OR	95% CI	p value
Age
< 5	1
6–15	1.69	1.46–1.96	< 0.001
16–30	1.80	1.53–2.11	< 0.001
> 31	1.91	1.54–2.38	< 0.001
Sex
Female	1
Male	0.94	0.85–1.04	0.248
Disease day
1–2	1
3–4	1.06	0.94–1.19	0.377
5	1.00	0.84–1.19	0.973
Clinical manifestation
No warning signs	1
Warning signs	1.47	1.28–1.70	< 0.001
Severe	1.66	1.28–2.16	< 0.001
Non-disclosed	0.90	0.76–1.07	0.227
DRU elevation (metres)
0–75	1
75–150	0.81	0.67–0.97	0.023
150+	0.61	0.52–0.72	< 0.001
DRU pop den (km2)
0–100	1
100–200	0.87	0.77–0.97	0.017
200+	1.32	1.14–1.53	< 0.001

OR unadjusted odds ratio, Pop den population density, DRU disease-reporting unit