Table 3.

Marginal effect of larviciding in Zimbabwe and Botswana

Larvae type	Marginal effect	IRR (CI)	P value	% reduction
All larvae
Both countries	−1.94	0.14 (0.09; 0.23)	<0.001	86
Zimbabwe	−1.06	0.35 (0.24; 0.51)	<0.001	65
Botswana	−2.51	0.08 (0.06; 0.11)	<0.001	92
Larval stage
Early instar
Both countries	−1.47	0.23 (0.17; 0.32)	<0.001	77
Zimbabwe	−1.23	0.29 (0.17; 0.50)	<0.001	71
Botswana	−1.83	0.16 (0.12; 0.22)	<0.001	84
Late instar
Both countries	−2.40	0.09 (0.04; 0.19)	<0.001	91
Zimbabwe	−0.56	0.57 (0.31; 1.03)	0.062	43
Botswana	−4.04	0.02 (0.01; 0.04)	<0.001	98
Larvae species
ALL Anopheles
Both countries	−1.63	0.20 (0.05; 0.76)	0.019	80
Zimbabwe	−0.64	0.53 (0.30; 0.92)	<0.025	47
Botswana	−3.01	0.05 (0.02; 0.13)	<0.001	95
ALL Culex
Both countries	−1.03	0.36 (0.10; 1.23)	0.102	64
Zimbabwe	−0.86	0.42 (0.26; 0.68)	<0.001	58
Botswana	−2.21	0.11 (0.05; 0.27)	<0.001	89