The Use of Insecticide-Treated Curtains for Control of Aedes aegypti and Dengue Virus Transmission in “Fraccionamiento” Style Houses in México

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 sample^1	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. aegypti^8
					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	Baseline^2	0 (6)	19.1 (100)	8.0 (100)	303	303	100	303	100	298	71	23.8	59	19.8
Olyset Plus	Window^3	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	Window^3	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	Window^3	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	Window^3	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	Interior^4	3 (5)	18.6 (97.4)	7.1 (88.8)	249	249	100	249	100	252	52	20.6	25	9.9
Olyset Plus	Interior^4	6 (4)	18.1 (94.8)	6.4 (80.0)	204	204	100	204	100	203	47	23.2	18	8.9
Olyset Plus	Interior^4	9 (4)	18.2 (95.3)	6.9 (86.2)	202	202	100	202	100	199	43	21.6	23	11.6
Olyset Plus	Interior^4	11 (4)	17.8 (93.2)	5.5 (68.8)	205	205	100	205	100	206	21	10.2	7	3.4
Non-treated	Baseline^2	0 (2)	ND	ND	102	0	0	0	0	179	0	0	0	0
Non-treated	Any location^5	3 (3)	ND	ND	149	0	0	0	0	152	0	0	0	0
Non-treated	Any location^5	6 (3)	ND	ND	150	0	0	0	0	150	0	0	0	0
Non-treated	Any location^5	9 (2)	ND	ND	101	0	0	0	0	101	0	0	0	0
Non-treated	Any location^5	11 (3)	ND	ND	152	0	0	0	0	153	0	0	0	0

Olyset 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.