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Table 4 Hazard ratio of a Plasmodium vivax infection following a previous malaria episode within 90 days of follow-up

From: Declining malaria transmission in rural Amazon: changing epidemiology and challenges to achieve elimination

  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)