Table 4.

Hazard ratio of a Plasmodium vivax infection following a previous malaria episode within 90 days of follow-up

	Rate P. vivax episode/100-person-months	Crude HR (95 % CI)	P value	Adjusted HR (95 % CI)	P value
Initial infection
P. falciparum	5.3 (3.2–8.7)	1		1
P. vivax	11.4 (9.8–12.2)	2.1 (1.2–3.7)	0.009	2.3 (1.3–4.0)	0.006
Mixed Infection	14.2 (9.4–21.6)	2.7 (1.4–5.1)	0.003	2.9 (1.5–5.7)	0.002
Gender
Female	10.5 (8.5–13.0)	1		1	0.983
Male	10.8 (9.0–12.9)	1.0 (0.8–1.3)	0.870	1.0 (0.8–1.3)
Age (years)
0–10	10.0 (7.7–13.0)	1		1
10–20	10.1 (7.5–13.7)	1.0 (0.7–1.6)	0.865	1.1 (0.7–1.5)	0.809
20–40	11.1 (8.5–14.5)	1.1 (0.8–1.6)	0.557	1.2 (0.8–1.8)	0.284
40–60	12.3 (9.0–16.9)	1.2 (0.8–1.8)	0.268	1.3 (0.9–2.0)	0.126
≥60	9.6 (5.4–16.8)	0.9 (0.5–1.7)	0.885	1.0 (0.5–1.7)	0.933
Residence area
Road ranches	8.7 (6.5–11.7)	1		1	0.091
Rural settlement	11.4 (9.8–13.3)	1.3 (0.9–1.8)	0.108	1.3 (1.0–1.9)
Season
Rainy	5.9 (4.4–8.0)	1		1	<0.001
Dry	13.6 (11.7–15.9)	2.4 (1.7–3.3)	<0.001	2.5 (1.8–3.5)
Use of ITN
No	11.0 (9.2–13.2)	1		1	0.284
Yes	10.3 (8.3–12.7)	0.9 (0.7–1.2)	0.564	0.9 (0.7–1.1)