Insecticide resistance status of Anopheles gambiae s.s population from M’Bé: a WHOPES-labelled experimental hut station, 10 years after the political crisis in Côte d’Ivoire

Table 1 Knock-down time of Anopheles gambiae s.s from M’Bé exposed to pyrethroids and DDT relative to the reference Kisumu Anopheles gambiae s.s strain

Insecticide	Strain	N	KdT₅₀(CI₉₅)	KdT₉₅(min)	RR₅₀	RR₉₅
DDT 4%	Kisumu	101	15.4 (12.8-18.5)	19.5 (14.1-27.1)	_	_
DDT 4%	M’Bé	193	NA	NA	NA	NA
*DDT 4% + PBO*	*M’Bé*	*105*	NA	NA	NA	NA
Permethrin 0.75%	Kisumu	101	17.3 (16.3-18.4)	23.9 (21.8-28.1)	_	_
Permethrin 0.75%	M’Bé	201	83.1 (73.9-99.2)	204.7 (155.7-313.7)	4.8 (4.1-5.6)	8.6 (6.0-12.2)
*Permethrin 0.75% + PBO*	*M’Bé*	*100*	*94.9 (76.2-134.7)*	*469.9 (276.8-1 146.7)*	*5.5 (4.1-7.2)*	*19.6 (9.9-38.5)*
α-cypermethrin 0.05%	Kisumu	99	17.8 (12.9-22.8)	39.1 (29.2-74.1)	_	_
α-cypermethrin 0.05%	M’Bé	197	90.3 (75.5-118.9)	341.6 (224.3-673.1)	5.1 (4.2-6.1)	8.7 (5.7-13.3)
*α-cypermethrin 0.05% + PBO*	*M’Bé*	*106*	*28 (26.4-29.6)*	*59.4 (54.3-66.4)*	*1.6 (1.4-1.7)*	*1.5 (1.3-1.8)*
Deltamethrin 0.05%	Kisumu	126	19.6 (16.8-22.5)	37.4 (31.3-50.4)	_	_
Deltamethrin 0.05%	M’Bé	208	83.2 (73.6-98.3)	274.9 (205.5-415.4)	4.2 (3.6-4.9)	7.4 (5.1-10.5)
*Deltamethrin 0.05% + PBO*	*M’Bé*	*103*	*41.4 (37.9-45.7)*	*99.1 (81.7-133.3)*	*2.1 (1.9-2.3)*	*2.6 (2.2-3.2)*
Etofenprox 0.5%	Kisumu	105	24.7 (21.9-27.5)	39.5 (34.4-49.7)	_	_
Etofenprox 0.5%	M’Bé	200	93.7 (80.7-116.9)	296.5 (210.7-499.4)	3.8 (3.1-4.6)	7.5 (4.9-11.5)
*Etofenprox 0.5% + PBO*	*M’Bé*	91	*83.2 (65.7-139.2)*	*265.1 (152.7-989.6)*	*3.4 (2.7-44.2)*	*6.7 (3.9-11.5)*

CI: confidence interval; KDT: knock-down time; KDT₅₀: time taken for 50% of the test mosquitoes to be knocked down; KDT₉₅: time taken for 95% of the test mosquitoes to be knocked down; RR: knock-down time ratio (KDT₅₀ of the tested population/KDT₅₀ of the susceptible Kisumu strain); NA: not available.

ISSN: 1475-2875