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Table 2 Knockdown time (kdT) for 50% and 95% of tested Anopheles gambiae s.l populations

From: Trends in DDT and pyrethroid resistance in Anopheles gambiaes.s. populations from urban and agro-industrial settings in southern Cameroon

Site

Insecticide

Period

N

kdT50 [CI95] (min)

kdT95 [CI95] (min)

RR

Resistant status

Ipono

4%DDT

Nov/2003

80

28.1 [22.4-31.9]

50.8 [45.0-62.7]

1.4

RC

 

0.05%Deltamethrin

 

79

8.3 [5.4-10.9]

24.0 [18.1-38.9]

0.8

S

 

0.75%Permethrin

 

79

11.5 [10.2-12.8]

44.3 [39.2-51.2]

1.3

S

 

4%DDT

Nov/2007

87

>60

>60

>3

R

 

0.05%Deltamethrin

 

95

13.7 [12.7-14.7]

34.1 [31.3-37.4]

1.4

RC

 

0.75%Permethrin

 

88

37.3 [34.1-40.6]

>60

4.1

R

Nkolondom

4%DDT

Nov/2003

80

>60

>60

>3

R

 

0.05%Deltamethrin

 

89

12.2 [3.7-18.8]

42.8 [32.7-61.0]

1.2

S

 

0.75%Permethrin

 

86

12.6 [9.6-15.4]

47.1 [37.3-67.4]

1.4

S

 

4%DDT

Nov/2007

84

>60

>60

>3

R

 

0.05%Deltamethrin

 

89

20.1 [17.1-22.8]

45.8 [39. 1-58.4]

2.1

RC

 

0.75%Permethrin

 

83

40.2 [37.6-42.8]

>60

4.5

RC

Mangoum

4%DDT

May/2003

80

>60

>60

>3

R

 

0.05%Deltamethrin

 

84

24.1 [22.4-25.1]

39.2 [37.1-42.0]

2.5

R

 

0.75%Permethrin

 

80

57.4 [52.3-68.0]

>60

6.6

R

 

4%DDT

May/2007

91

>60

>60

>3

R

 

0.05%Deltamethrin

 

84

19.4 [16.4-22.0]

48.3 [41.8-59.1]

2.0

RC

 

0.75%Permethrin

 

106

54.2 [51.9-57.1]

>60

6.1

R

Bonanloka

4%DDT

May/2001

80

49.3 [41.8-58.7]

>60

2.6

RC

 

0.05%Deltamethrin

 

86

22.4 [21.2-23.7]

34.8 [31.2-39.0]

2.4

RC

 

0.75%Permethrin

 

91

16.3 [14.9-17.7]

25.7 [22.4-29.6]

1.7

R

 

4%DDT

May/2005

80

51.6 [41.9-54.0]

>60

2.7

R

 

0.05%Deltamethrin

 

83

8.3 [7.6-9.1]

18.6 [16.8-21.1]

0.8

S

 

0.75%Permethrin

 

85

6.2 [3.6-8.5]

23.8 [18.0-37.2]

0.7

S

 

4%DDT

May/2007

87

37.9 [36.5-39.5]

>60

1.9

RC

 

0.05%Deltamethrin

 

84

12.8 [10.6-14.6]

24.1 [20.4-31.6]

1.3

RC

 

0.75%Permethrin

 

88

15.2 [13.2-17.1]

35.3 [30.7-42.6]

1.7

RC

  1. N: sample size; kdT50: knockdown time for 50% mosquitoes; kdT95: knockdown time for 95% mosquitoes; CI95: confidence interval at 95%; min: minutes; RR: resistance ratio (kdT50 of the tested population/kdT50of the Kisumu strain); S: susceptible; RC: resistance to be confirmed; R: resistant; Nov: November.