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Table 7 Factors related to anopheline larval density.

From: Highly focused anopheline breeding sites and malaria transmission in Dakar

Habitat characteristics

Number of obs.

Number of dips

Total number of anopheline larvae

Anopheline larval density

(per dip)

RR

95%CI

p-value

Zone

      

0.028

Hann Maristes

18

209

208

1.00

ref.

  

Pikine

27

140

357

2.55

1.66

0.77 – 3.60

0.198

Université

14

54

246

4.56

2.23

0.91 – 5.46

0.080

Yarakh

2

18

110

6.11

2.28

0.41 – 12.76

0.348

Ouest Foire

22

93

578

6.22

3.09

1.38 – 6.95

0.006

Almadies

38

179

1309

7.31

4.09

1.98 – 8.45

<0.001

Gibraltar

2

9

160

17.78

8.10

1.48 – 44.39

0.016

Parcelles Grand Medine *

0

-

-

-

   

Liberté 5

0

-

-

-

   

Yoff Village

0

-

-

-

   

Habitat type

      

<0.001

"Céanes", cemented weels or basins

8

53

126

2.38

ref.

  

Waterproof containers

5

17

30

1.76

2.56

0.45 – 14.72

0.291

Swamp areas, marshes, ponds or lakes

22

116

467

4.03

14.76

3.76 – 57.88

<0.001

Ditches or puddles

80

488

2137

4.38

15.96

4.44 – 57.36

<0.001

Man-made water collections

4

16

82

5.13

17.45

2.62 – 116.14

0.003

Canals

4

12

126

10.50

22.50

3.90 – 129.71

<0.001

Period

      

0.762

Weeks 1 – 4

57

328

1775

5.41

ref.

  

Weeks 5 – 8

66

374

1193

3.19

0.94

0.63 – 1.40

 

Temporary collection

      

0.292

No

23

134

379

2.83

ref.

  

Yes

100

568

2589

4.56

1.44

0.73 – 2.85

 

Perimeter (metres)

      

0.755

<20 m

49

226

1078

4.77

ref.

  

>= 20 m

74

476

1890

3.97

0.93

0.59 – 1.46

 

Water temperature (n = 93)

      

<0.001

<30°C

33

228

475

2.08

ref.

  

>= 30°C

60

307

1611

5.25

3.34

1.97 – 5.68

 

Turbidity (n = 88)

      

0.592

<13 (clear)

28

142

700

4.93

ref.

  

>= 13 (turbid)

60

392

1261

3.22

0.87

0.52 – 1.46

 

Surface vegetation (%)

      

0.001

<20%

89

504

2596

5.15

ref.

  

>= 20%

34

198

372

1.88

0.41

0.24 – 0.70

 

Sunlight (%, n = 120)

      

0.674

<80%

72

447

1194

2.67

ref.

  

>= 80%

48

244

1665

6.82

1.13

0.64 – 2.00

 

Presence of predator(n = 104)

      

0.865

No

48

308

1326

4.31

ref.

  

Yes

56

286

1245

4.35

0.96

0.59 – 1.56

 

Presence of Culicinae larvae (n = 106)

      

0.016

No

51

291

1259

4.33

ref.

  

Yes

55

321

1033

3.22

1.71

1.10 – 2.64

 
  1. Adjusted (by study area) risk ratio (RR) estimated by GEE negative binomial regression model. Bivariate analysis; 123 observations of anopheline breeding sites, unless otherwise indicated.
  2. * Water collections found outside of the 200 × 200 m study area