Background
Malaria in The Gambia
Methods
Study sites
Study design
Laboratory processing
Statistics
Ethical clearance
Results
Phenotypic resistance to DDT and deltamethrin in a WHO bioassay
Insecticide | Species | Region | Mortality (%) | χ2
| Df | P |
---|---|---|---|---|---|---|
DDT |
An. gambiae s.s.
| East | 6 | 82.42 | 1 | <0.001 |
West | 97 | |||||
An. arabiensis
| East | 92 | 0.11 | 1 | 0.74 | |
West | 97 | |||||
An. coluzzii
| East | 67 | 4.75 | 1 | 0.03 | |
West | 94 | |||||
Deltamethrin |
An. gambiae s.s.
| East | 41 | 32.56 | 1 | <0.001 |
West | 86 | |||||
An. arabiensis
| East | 97 | 2.55 | 1 | 0.11 | |
West | 83 | |||||
An. coluzzii
| East | 89 | 0.04 | 1 | 0.85 | |
West | 97 |
Resistance association of DNA markers
Species |
Vgsc-1014F
|
Vgsc-1014S
|
Vgsc-1575Y
|
Gste2-114T
|
Ace1-119S
|
---|---|---|---|---|---|
Allele frequency (with 95 % confidence intervals) of molecular resistance markers by species | |||||
An. gambiae s.s.
| 0.51 (0.45–0.55) | 0.004 (8.56−5–0.01) | 0.13 (0.1–0.16) | 0.097 (0.075–0.12) | 0.003 (5.68−4–0.01) |
An. arabiensis
| 0.05 (0.02–0.06) | 0.14 (0.1–0.17) | 0.002 (1.13−4–0.01) | 0.017 (0.008–0.04) | 0 (0–0.1) |
An. coluzzii
| 0.0012 (6.16−5–7.62−3) | 0 (0–0.01) | 0.0012 (6.16−5–0.01) | 0.67 (0.67–0.74) | 0 (0–0.01) |
An. coluzzii × An. gambiae hybrid | 0.15 (0.063–0.31) | 0 (0–0.11) | 0.08 (0.02–0.22) | 0 (0–0.11) | 0 (0–0.11) |
Species | Insecticide | Marker | Odds ratio | 95 % confidence intervals | P | |
---|---|---|---|---|---|---|
Lower | Upper | |||||
An. gambiae s.s. | DDT | Kdr | 253.74 | 48.07 | 6302.05 | <0.001 |
Gste2 | 3.4 | 1.43 | 9.18 | 0.01 | ||
Deltamethrin | Kdr | 8.37 | 3.99 | 18.47 | <0.001 | |
Gste2 | 3.4 | 1.175 | 10.29 | 0.02 | ||
An. coluzzii
| DDT | Gste2 | 1.5 | 0.34 | 11.35 | 0.72 |
Deltamethrin | Gste2 | 0.23 | 0.06 | 0.78 | 0.02 |
Factor | Df | Deviance | Residual Df | Residual deviance | P |
---|---|---|---|---|---|
DDT | |||||
Species | 5 | 190.56 | 490 | 331.83 | <0.001 |
Village | 8 | 114.2 | 482 | 217.62 | <0.001 |
Kdr
| 5 | 51.04 | 477 | 166.58 | <0.001 |
1575y
| 2 | 1.05 | 475 | 165.53 | 0.59 |
Gste2
| 2 | 1.8 | 473 | 163.73 | 0.41 |
Kdr:1575Y
| 1 | 0.86 | 472 | 162.87 | 0.35 |
kdr:gste2
| 4 | 4.33 | 468 | 158.55 | 0.36 |
1575Y:gste2
| 2 | 1.13E−08 | 466 | 158.55 | 1 |
Deltamethrin | |||||
Species | 5 | 50.46 | 482 | 371.69 | <0.001 |
Village | 8 | 34.45 | 474 | 337.24 | <0.001 |
Kdr
| 5 | 28.22 | 469 | 309.02 | <0.001 |
1575y
| 2 | 3.13 | 467 | 305.9 | 0.21 |
Gste2
| 2 | 4.26 | 465 | 301.63 | 0.12 |
Kdr:1575Y
| 1 | 0.09 | 464 | 301.54 | 0.76 |
Kdr:gste2
| 3 | 4.07 | 461 | 297.47 | 0.25 |
1575Y:gste2
| 3 | 0.86 | 458 | 296.61 | 0.83 |