Background
Methods
Study area
Design of the huts
Treatments arms
Volunteer participants and mosquito collections
-
the reduction in female mosquitoes hut entry relative to the control (deterrence);
-
the proportion of female mosquitoes collected on the veranda (exophily);
-
the reduction in female mosquitoes blood feeding relative to the control hut (blood feeding inhibition);
-
the proportion of female mosquitoes found dead in the morning and after 24 h (immediate mortality and delayed mortality);
Bioassays
Side effects perceived by the sleepers
Data analysis
Result
Bioassays
Point of exhaustion and initial bioefficacy of the treated nets
Treatments | N mosquitoes tested | % KD after 60 min | % Mortality after 24 h |
---|---|---|---|
Untreated polyester net | 52 | 0a | 0a |
Life Net to be unwashed | 54 | 100b | 100b |
Life Net to be washed 20 times | 53 | 100b | 100b |
Life Net to be washed 30 times | 54 | 100b | 100b |
CTN 25 mg/m2 to be washed just before exhaustion | 53 | 100b | 100b |
CTN 25 mg/m2 to be washed 20 times | 57 | 100b | 100b |
Number of washes | N mosquitoes tested | % KD after 60 min | % Mortality after 24 h | Control % Mortality after 24 h (n) |
---|---|---|---|---|
0 wash | 53 | 100 | 100 | 0 (51) |
1 wash | 52 | 98 | 90 | 0 (54) |
2 washes | 54 | 93 | 83 | 0 (53) |
3 washes | 52 |
85
|
77
| 0 (56) |
Treatments | N mosquitoes tested | % KD after 60 min | % Mortality after 24 h |
---|---|---|---|
Untreated polyester net | 51 | 0a | 0a |
Life Net unwashed | 53 | 100b | 100b |
Life Net washed 20 times | 50 | 100b | 100b |
Life Net washed 30 times | 51 | 100b | 100b |
CTN 25 mg/m2 washed just before exhaustion | 53 | 94b | 92c |
CTN 25 mg/m2 washed 20 times | 50 | 94b | 74d |
Bioefficacy of the treated nets after field testing
Treatments | N mosquitoes tested | % KD after 60 min | % Mortality after 24 h |
---|---|---|---|
Untreated polyester net | 49 | 0a | 0a |
Life Net unwashed | 52 | 100b | 100b |
Life Net washed 20 times | 54 | 100b | 100b |
Life Net washed 30 times | 60 | 100b | 100b |
CTN 25 mg/m2 washed just before exhaustion | 53 | 94b | 81c |
CTN 25 mg/m2 washed 20 times | 57 | 63c | 60d |
Efficacy under experimental huts
Untreated Net | LifeNet 0 wash | LifeNet 20 washes | LifeNet 30 washes | CTN 25 mg/m2 Exhaust | CTN 25 mg/m2 20 washes | |
---|---|---|---|---|---|---|
Total females caught | 689ab | 871a | 704ab | 654b | 825ab | 738ab |
females caught/night | 9.-56 | 12.-09 | 9.-77 | 9.-08 | 11.-45 | 10.-25 |
Deterrency (%) | – | −26 | −2 | 5 | −20 | −7 |
Total females veranda | 231 | 338 | 309 | 260 | 276 | 339 |
Exophily (%) | 34a | 39b | 44bc | 40b | 33a | 46c |
95% Confidence limits | 30–37 | 36–42 | 40–48 | 36–44 | 30–37 | 42–50 |
Induced Exophily (%) | – | 16 | 31 | 19 | NS | 37 |
Total females blood fed | 224 | 12 | 13 | 15 | 40 | 79 |
Blood fed (%) | 33a | 1c | 2c | 2c | 5b | 11d |
95% Confidence limits | 29–36 | 1.-2 | 1.-3 | 1.-3 | 3.-6 | 8.-13 |
Blood feeding inhib. (%) | – | 96 | 94 | 93 | 85 | 67 |
Total females dead | 79 | 846 | 662 | 599 | 687 | 440 |
Overall mortality (%) | 11a | 97c | 94d | 92d | 83b | 60e |
95% Confidence limits | 9.-14 | 96–98 | 92–96 | 89–94 | 81–86 | 56–63 |
Corrected for control (%) | – | 97 | 93 | 91 | 81 | 54 |
Untreated Net | LifeNet 0 wash | LifeNet 20 washes | LifeNet 30 washes | CTN 25 mg/m2 Exhaust | CTN 25 mg/m2 20 washes | |
---|---|---|---|---|---|---|
Total females caught | 87a | 65a | 69a | 76a | 62a | 86a |
females caught/night | 1.20 | 0.90 | 0.96 | 1.05 | 0.86 | 1.19 |
Deterrency (%) | – | 25 | 21 | 13 | 29 | 1 |
Total females veranda | 13 | 36 | 41 | 47 | 33 | 33 |
Exophily (%) | 15 a | 55 b | 59 b | 62 b | 53 bc | 38 c |
95% Confidence limits | 7–22 | 43–67 | 48–71 | 51–73 | 41–66 | 28–49 |
Induced Exophily (%) | – | 271 | 298 | 314 | 256 | 157 |
Total females blood fed | 33 | 3 | 1 | 8 | 9 | 26 |
Blood fed (%) | 38 a | 5 bc | 1c | 11b | 15b | 30a |
95% Confidence limits | 28–48 | 0–10 | 0–4 | 4.-17 | 6.-23 | 21–40 |
Blood feeding inhib. (%) | – | 88 | 96 | 72 | 62 | 20 |
Total females dead | 1 | 49 | 48 | 42 | 27 | 22 |
Overall mortality (%) | 1a | 75c | 70cd | 55bd | 44b | 26e |
95% Confidence limits | 0–3 | 65–86 | 59–80 | 44–66 | 31–56 | 16–35 |
Corrected for control (%) | – | 75 | 69 | 55 | 43 | 25 |