Insecticide resistance of Anopheles sinensis after elimination of malaria in Henan Province, China

Parasites & Vectors

Table 2 Adjusted mortality rates and knockdown times of Anopheles sinensis exposed to four insecticides in Henan Province

Sampling sites/populations	Insecticide	Sample size (n)	Knockdown in 1 h (n)	Rate of knockdown in 1 h (%)	KT₅₀(95% CI), per min	Deaths in 24 h (n)	Adjusted rate of deaths in 24 h (%)	Status^a
Pingqiao	Beta-cyfluthrin	86	21	24.42	315.73 (143.53,2848.63)	37	36.24	CR
	Deltamethrin	87	66	75.86	33.35 (30.21,37.10)	76	85.85	CR
	Propoxur	87	42	48.28	70.77 (56.28,102.16)	63	68.39	CR
	Malathion	89	59	66.29	29.81 (25.28, 35.59)	87	97.43	PR
	Control	55	0	–	–	7	12.73^c	–
Tanghe	Beta-cyfluthrin	55	25	45.45	68.18 (55.03, 96.65)	39	70.91	CR
	Deltamethrin	113	23	20.35	101.10 (81.66,148.67)	39	25.38	CR
	Propoxur	47	34	72.34	36.60 (33.37,40.33)	39	80.60	CR
	Malathion	49	45	91.84	32.09 (29.73,34.53)	48	97.67	PR
	Control	49	0	–	–	6	12.24^c	–
Xiangcheng	Beta-cyfluthrin	67	25	37.31	96.69 (69.21,183.34)	23	34.33^d	CR
	Deltamethrin	74	8	10.81	237.80 (125.09,1719.26)	22	29.73^d	CR
	Propoxur	101	51	50.50	55.64 (49.13,65.57)	38	37.62^d	CR
	Malathion	126	104	82.54	32.33 (27.80,37.43)	125	99.21^d	S
	Control	60	0	–	–	2	3.33^c	–
Xiangfu	Beta-cyfluthrin	81	2	2.47	NC^b	8	3.28	CR
	Deltamethrin	86	2	2.33	NC	12	7.66	CR
	Propoxur	84	19	22.62	159.36 (101.27,412.00)	13	9.29	CR
	Malathion	102	16	15.69	133.81 (96.65,254.71)	68	64.23	CR
	Control	44	0	–	–	3	6.82^c	–

CI Confidence interval, KT₅₀ median knockdown time for 50% of the tested mosquitoes, NC not calculated,
^aCR, Confirmed resistance (mortality < 90%); PR, possible resistance (90% ≤ mortality ≤ 97%); S, susceptible (mortality ≥ 98%)
^bUnable to calculate mean KT₅₀ due to low knockdown rate
^cMean mortality rates in the controls
^dMean unadjusted rate of death in 24 h

ISSN: 1756-3305