Table 4. Influence of topography on risk factors associated with submicroscopic malaria infection.

Risk factor	Category	Lakeshore zone1			Hillside zone			Highland plateau zone			Risk ratio2
		Infection (n, %)	AOR (95% CI)1	p-value	Infection (n, %)	AOR (95% CI) 1	p-value	Infection (n, %)	AOR (95% CI) 1	p-value	Hillside (95% CI)2	p-value	Plateau (95% CI)2	p-value
Age	0–4 years	9 (10.6)	0.23 (0.10, 0.57)	0.002	6 (7.7)	0.49 (0.18, 1.28)	0.149	4 (5.1)	0.57 (0.16, 2.01)	0.381	0.73 (0.27, 1.95)	0.522	0.48 (0.16, 1.51)	0.199
	5-<15 years	61 (31.0)	1.02 (0.57, 1.83)	0.943	32 (17.5)	1.14 (0.62, 2.13)	0.673	12 (7.8)	0.96 (0.41, 2.24)	0.915	0.56 (0.39, 0.82)	0.002	0.25 (0.14, 0.45)	<0.0001
	≥15 years	58 (17.1)	1		43 (12.9)	1		28 (8.5)	1		0.75 (0.52, 1.09)	0.128	0.50 (0.33, 0.76)	0.001
Sex	Female	69 (18.0)	0.67 (0.45, 0.98)	0.042	44 (11.8)	0.67 (0.42, 1.08)	0.102	28 (8.1)	1.08 (0.57, 2.05)	0.812	0.66 (0.46, 0.93)	0.018	0.45 (0.30, 0.68))	<0.0001
	Male	59 (24.8)	1		37 (16.6)	1		16 (7.5)	1		0.67 (0.46, 0.97)	0.030	0.30 (0.18, 0.51)	<0.0001
Bed net usage	No net	6 (24.0)	1.39 (0.50, 3.8)	0.523	2 (11.1)	1.04 (0.22, 5.00)	0.958	6 (17.1)	3.37 (1.19, 9.54)	0.022	0.46 (0.11, 2.03)	0.502	0.71 (0.26, 1.96)	0.512
	Use net	122 (20.4)	1		79 (13.9)	1		38 (7.2)	1		0.67 (0.52, 0.87)	0.002	0.35 (0.25, 0.50)	<0.0001
Wall type	Block	17 (15.9)	0.91 (0.43, 1.91)	0.798	13 (17.1)	1.18 (0.53, 2.65)	0.682	10 (6.0)	0.55 (0.15, 2.06)	0.375	1.12 (0.61, 2.25)	0.823	0.38 (0.18, 0.79)	0.007
	Mud & wood	90 (22.3)	1.42 (0.81, 2.50)	0.221	40 (10.7)	0.68 (0.37, 1.24)	0.209	28 (8.6)	0.73 (0.23, 2.37)	0.601	0.48 (0.34, 0.67)	<0.0001	0.38 (0.26, 0.57)	<0.0001
	Mud & Cement	21 (18.8)	1		28 (19.2)	1		6 (9.3)	1		1.02 (0.61, 1.70)	0.920	0.50 (0.18, 1.36)	0.152
Symptoms	Asymptomatic	86 (18.4)	0.85 (0.49, 1.46)	0.558	63 (12.2)	0.56 (0.27, 1.16)	0.118	34 (7.1)	1.18 (0.37, 3.78)	0.776	0.66 (0.49, 0.89)	0.125	0.54 (0.40, 0.75)	<0.0001
	Symptomatic	42 (27.1)	1		18 (23.1)	1		10 (7.1)	1		0.29 (0.19, 0.44)	<0.0001	0.09 (0.03, 0.23)	<0.0001
Occupation/ income generating activity	Farmer	28 (15.9)	0.37 (0.18, 0.75)	0.006	16 (9.2)	0.54 (0.25, 1.15)	0.109	16 (9.4)	1.36 (0.55, 3.35)	0.500	0.58 (0.32, 1.03)	0.058	0.59 (0.33, 1.05)	0.067
	Commercial sales	9 (13.0)	0.27 (0.11, 0.68)	0.005	15 (16.1)	1.11 (0.48, 2.56)	0.805	6 (4.1)	0.58 (0.15, 2.06)	0.171	0.59 (0.33, 1.05)	0.584	0.32 (0.09, 1.12)	0.056
	Child younger than working age	71 (25.0)	0.31 (0.14, 0.68)	0.003	35 (15.1)	1.04 (0.42, 2.57)	0.927	16 (7.1)	3.71 (1.00, 13.79)	0.050	0.60 (0.42, 0.86)	0.006	0.28 (0.17, 0.48)	<0.0001
	Unemployed	20 (21.5)	1		15 (15.6)	1		9 (9.9)	1		0.73 (0.40, 1.33)	0.299	0.46 (0.22, 0.96)	0.030
Season	Wet (2019)	28 (18.1)	1.5 (0.77, 3.05)	0.225	17 (11.3)	1.11 (0.50, 2.46)	0.795	14 (9.2)	0.68 (0.28, 1.70)	0.414	0.78 (0.49, 1.25)	0.296	0.30 (0.14, 0.60)	0.0002
	Dry (2019)	50 (29.9)	2.54 (1.26, 5.09)	0.009	31 (19.6)	1.69 (0.84, 3.42)	0.143	9 (6.9)	0.77 (0.32, 1.83)	0.548	0.57 (0.35, 0.92)	0.018	0.42 (0.23, 0.74)	0.002
	Wet (2020)	31 (21.5)	3.4 0 (1.57, 7.36)	0.002	17 (13.8)	1.11 (0.43, 2.90)	0.829	6 (5.0)	0.16 (0.04, 0.63)	0.009	0.56 (0.31, 1.00)	0.049	0.25 (0.11, 0.57)	0.0003
	Dry (2020)	19 (12.2)	1		16 (9.8)	1		15 (9.6)	1		0.74 (0.43, 1.25)	0.251	1.19 (0.61, 2.32)	0.610

¹ Multivariate binary logistic regression model used for risk factor analysis.

² Significance by χ2 test for risk ratio of submicroscopic malaria infection according to topographic zone with Lakeshore zone as referent.