Table 11.
Outcome of in-house cylinder bioassay for challenge of insecticide susceptible and resistant strains of Aedes aegypti with Olyset Plus and similar but non-treated curtains aged in homes in Mérida City, and amounts of active ingredient (permethrin) and synergist (PBO) present in the samples.
| Type of net sample1 | Location in homes | Months exposed in homes (no. samples) | Mean amount (grams) of active ingredient (permethrin) or synergist (PBO) per kilogram of net sample (% relative to baseline value) | New Orleans insecticide susceptible reference strain of Ae. aegypti | Local Mérida City insecticide resistant Vergel strain of Ae. aegypti8 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. tested | Knocked Down (1 hr) | Dead (24 h) | No. tested | Knocked Down (1 hr) | Dead (24 h) | |||||||||
| Permethrin | PBO | No. | % | No. | % | No. | % | No. | % | |||||
| Olyset Plus | Baseline2 | 0 (6) | 19.1 (100) | 8.0 (100) | 303 | 303 | 100 | 303 | 100 | 298 | 71 | 23.8 | 59 | 19.8 |
| Olyset Plus | Window3 | 3 (8)6 | 18.6 (97.4) | 4.9 (61.2) | 412 | 412 | 100 | 412 | 100 | 402 | 93 | 23.1 | 49 | 12.2 |
| Olyset Plus | Window3 | 6 (8)6 | 17.6 (92.1) | 3.4 (42.5) | 401 | 399 | 99.5 | 399 | 99.5 | 402 | 54 | 13.4 | 18 | 4.5 |
| Olyset Plus | Window3 | 9 (6)7 | 16.5 (86.4) | 2.1 (26.2) | 304 | 301 | 99.0 | 290 | 95.4 | 303 | 24 | 7.9 | 12 | 4.0 |
| Olyset Plus | Window3 | 11 (6)7 | 16.8 (88.0) | 1.6 (20.0) | 302 | 288 | 95.4 | 247 | 81.8 | 306 | 14 | 4.6 | 7 | 2.3 |
| Olyset Plus | Interior4 | 3 (5) | 18.6 (97.4) | 7.1 (88.8) | 249 | 249 | 100 | 249 | 100 | 252 | 52 | 20.6 | 25 | 9.9 |
| Olyset Plus | Interior4 | 6 (4) | 18.1 (94.8) | 6.4 (80.0) | 204 | 204 | 100 | 204 | 100 | 203 | 47 | 23.2 | 18 | 8.9 |
| Olyset Plus | Interior4 | 9 (4) | 18.2 (95.3) | 6.9 (86.2) | 202 | 202 | 100 | 202 | 100 | 199 | 43 | 21.6 | 23 | 11.6 |
| Olyset Plus | Interior4 | 11 (4) | 17.8 (93.2) | 5.5 (68.8) | 205 | 205 | 100 | 205 | 100 | 206 | 21 | 10.2 | 7 | 3.4 |
| Non-treated | Baseline2 | 0 (2) | ND | ND | 102 | 0 | 0 | 0 | 0 | 179 | 0 | 0 | 0 | 0 |
| Non-treated | Any location5 | 3 (3) | ND | ND | 149 | 0 | 0 | 0 | 0 | 152 | 0 | 0 | 0 | 0 |
| Non-treated | Any location5 | 6 (3) | ND | ND | 150 | 0 | 0 | 0 | 0 | 150 | 0 | 0 | 0 | 0 |
| Non-treated | Any location5 | 9 (2) | ND | ND | 101 | 0 | 0 | 0 | 0 | 101 | 0 | 0 | 0 | 0 |
| Non-treated | Any location5 | 11 (3) | ND | ND | 152 | 0 | 0 | 0 | 0 | 153 | 0 | 0 | 0 | 0 |
1Olyset Plus curtain samples were treated with permethrin and PBO; Non-treated curtain samples were similar but without permethrin or PBO. 2Baseline curtain samples were not exposed in homes. 3Curtain samples continuously exposed in south- or north-facing windows. 4Curtain samples placed in the interior part of a home and not exposed to direct sunlight. 5Curtain samples exposed in south- or north-facing windows, or in the interior of the home. 6Including 4 curtain samples from south-facing windows and 4 from north-facing windows. 7Including 3 curtain samples from south-facing windows and 3 from north-facing windows. 8Frequency of the knockdown resistance-conferring I1,016 allele mutation of ~90%, with ~80% I1,016 homozygotes, in the F1 generation of the strain; the F2 generation was used in these bioassays. ND = none detected.