Table 2 Underlying risk factors of malaria infection (2016–2018) (n = 18,061)

Sex

 Female

710 (34.6)

7392 (46.2)

1*

1

119 (34.1)

7983 (45.1)

1*

1

 Male

1343 (65.4)

8616 (53.8)

1.62 (1.47–1.79)

2.00 (1.80–2.23)

230 (65.9)

9729 (54.9)

1.59 (1.27–1.98)

1.83 (1.44–2.32)

Age (years)

 < 5

202 (9.8)

3424 (21.4)

1*

1

53 (15.2)

3573 (20.2)

1

1

 5–14

467 (22.7)

4062 (25.4)

1.95 (1.64–2.31)

1.79 (1.51–2.12)

82 (23.5)

4447 (25.1)

1.24 (0.88–1.76)

1.16 (0.82–1.64)

 15–24

602 (29.4)

3274 (20.5)

3.12 (2.64–3.68)

2.46 (2.07–2.92)

87 (24.9)

3789 (21.4)

1.55 (1.10–2.18)

1.15 (0.81–1.64)

 ≥ 25

782 (38.1)

5248 (32.8)

2.53 (2.15–2.97)

1.86 (1.56–2.22)

127 (36.4)

5903 (33.3)

1.45 (1.05–2.00)

0.94 (0.67–1.31)

Seasonal variation

 Dry season

(Jan–Apr)

310 (15.1)

2954 (18.5)

1*

1

57 (16.3)

3207 (18.1)

1*

1

 Rainy season

(May–Sep)

1,092 (53.2)

8652 (54.0)

1.20 (1.05–1.37)

1.63 (1.41–1.87)

169 (48.4)

9575 (54.1)

0.99 (0.73–1.34)

1.21 (0.89–1.66)

 Cold season

(Oct–Dec)

651 (31.7)

4402 (27.5)

1.41 (1.22–1.63)

3.69 (3.11–4.39)

123 (35.2)

4930 (27.8)

1.40 (1.02–1.93)

3.16 (2.21–4.52)

Transportation conditions^a

 Good

591 (28.8)

9776 (61.1)

1*

1

101 (28.9)

10,266 (58.0)

1*

1

 Poor

1462 (71.2)

6232 (38.9)

3.88 (3.51–4.29)

7.13 (6.31–8.06)

248 (71.1)

7446 (42.0)

3.39 (2.68–4.27)

6.05 (4.64–7.87)