Table 3. Mortality of Anopheles gambiae s.l. after 24-hr post exposure to 1x, 5x and 10x concentrations of deltamethrin in WHO bioassays and associated resistance intensity based on WHO classification [14].
| Sites | Deltamethrin diagnostic concentration (%) | ||||
|---|---|---|---|---|---|
| 1x (0.05) | 5x (0.25) | 10x (0.5) | |||
| Lagos: Ikorodu Badagry | No. exposed | 120 | 120 | 120 | High |
| Kdt50 (CI) minutes | 25.8 (23.7–27.2) | 18.5 (16.1–21.2) | 13.2(12.1–15.8) | ||
| Kdt95 (CI) minutes | 38.5 (37.1–40.1) | 29.2 (27.4 31.5) | 22.1 (19.0–24.6) | ||
| 24-h % mortality | 30.0 | 70.8 | 93.3 | ||
| Ogun: Ipokia-Irolu | No. exposed | 100 | 100 | 100 | Moderate |
| Kdt50 (CI) minutes | 30.8 (27.2–33.2) | 20.5 (18.1–23.5) | 14.5(12.0–16.2) | ||
| Kdt95 (CI) minutes | 42.2 (40.1–44.4) | 27.4 (25.2 29.0) | 21.1 (19.9–23.7) | ||
| 24-h % mortality | 41.0 | 75.0 | 99.0 | ||
| Edo: Igara | No. exposed | 120 | 100 | NA* | Low |
| Kdt50 (CI) minutes | 15.0 (13.6–17.2) | 13.0 (12.8–15.1) | |||
| Kdt95 (CI) minutes | 30.8 (27.0–32.2) | 25.8 (24.3–27.4) | |||
| 24-h % mortality | 87.5 | 100 | |||
| Anambra: Achalla | No. exposed | 120 | 120 | NA* | Low |
| Kdt50 (CI) minutes | 18.5 (16.8–21.2) | 16.2 (14.1–17.9) | |||
| Kdt95 (CI) minutes | 32.4 (30.2–33.1) | 25.2 (24.3–27.6) | |||
| 24-h % mortality | 76.7 | 98.3 | |||
| Niger: New Bussa | No. exposed | 120 | 120 | 110 | High |
| Kdt50 (CI) minutes | 25.3 (24.2–27.2) | 19.6 (17.4–22.5) | 13.8(11.8–15.4) | ||
| Kdt95 (CI) minutes | 39.2 (37.0–42.8) | 27.6 (25.5 28.8) | 19.5 (18.0–21.2) | ||
| 24-h % mortality | 61.7 | 85.0 | 94.5 | ||
| Kwara: Ayede | No. exposed | 120 | 120 | NA* | Low |
| Kdt50 (CI) minutes | 17.8 (15.2–19.8) | 14.2 (12.5–16.1) | |||
| Kdt95 (CI) minutes | 30.4 (28.2–32.1) | 26.4 (24.9–29.1) | |||
| 24-h % mortality | 76.7 | 100 | |||
*NA (Not applicable): 98–100% mortality at 5× dose indicates a low resistance intensity. Not necessary to assay at 10x dose.