Table 1. Virological and demographic data by disease severity.

Variable	DF (n = 289)	DHF (n = 169)	p-value	Crude OR for DHF	Adjusted OR for DHF
	n (%)	n (%)		(95% CI)	(95% CI)*
Serotype 1	108 (67)	54 (33)	.	1	1
Serotype 2	58 (57)	44 (43)	0.652	1.5 (0.9, 2.5)	1.2 (0.7, 2.0)
Serotype 3	75 (61)	48 (39)	1	1.3 (.8, 2.1)	1.5 (0.9, 2.4)
Serotype 4	44 (69)	20 (31)	1	0.9 (0.5, 1.7)	0.6 (0.3 1.2)
Male	159 (63)	95 (37)	.	1	1
Female	130 (64)	74 (36)	0.804	1.0 (0.7, 1.4)	1.0 (0.6, 1.4)
Mean age in years (SD)	8.5 (3.0)	8.7 (3.1)	0.382	.	.
age	.	.	.	1.0 (1.0, 1.0)	1.0 (0.9, 1.0)
age>65 months	.	.	.	1.0 (1.0, 1.0)	1.0 (1.0, 1.1)
Primary infection	86 (86)	14 (14)	.	1	1
Secondary infection	202 (57)	155 (43)	<0.001	4.7 (2.6, 8.6)	5.1 (2.7, 9.5)
AB blood type	12 (4)	16 (10)	0.022	2.4 (1.1, 5.2)	3.0 (1.3, 7.0)

*We adjusted for sex, age, blood type, and serological response profile.