scholarly journals The residual effect of lambda-cyhalothrin, deltamethrin and dichlorodiphenyltrichloroethane in Zhombe, Kwekwe district, Zimbabwe

2012 ◽  
Vol 44 (2) ◽  
pp. 10
Author(s):  
N. Lukwa ◽  
A. Makuwaza ◽  
S.L. Mutambu ◽  
P. Munosiyei

Indoor residual house spraying using lambda-cyhalothrin, deltamethrin and dichlorodiphenyltrichloroethane (DDT) was conducted in Zhombe Resettlement area, Zimbabwe. A total of 204/219 (93.1%), 224/260 (86.2%) and 257/325 (79.1%) rooms were sprayed with lambda-cyhalothrin, deltamethrin and DDT wettable powders respectively. Bioassays were conducted on sprayed walls and roofs using 3-5 day old laboratory reared susceptible <em>Anopheles gambiae sensu lato </em>mosquitoes placed in World Health Organization cones. <br />Bioassays conducted on sprayed walls (1 month), showed that efficacy of lambda-cyhalothrin was the same with DDT but different with deltamethrin and this trend continued in the 2<sup>nd</sup> month. During the 3rd month, lambda-cyhalothrin killed more mosquitoes than deltamethrin (P=1.931x10<sup>-14</sup>), DDT killed more mosquitoes than deltamethrin (P=0.0001) and lambda-cyhalothrin killed more mosquitoes than DDT (walls). Efficacy of lambda-cyhalothrin and DDT was the same 4 months post spray (P=0.487), notable differences were seen in lambdacyhalothrin and deltamethrin (P=2.57x10<sup>-6</sup>), DDT and deltamethrin (P=2.17-10<sup>-8</sup>). Efficacy of lambda-cyhalothrin and DDT was the same 5 months post spray (P=0.244), major differences were found in lambdacyhalothrin and deltamethrin (P=0.000), DDT and deltamethrin (P=5.18x10<sup>-5</sup>) and this trend continued in the 6<sup>th</sup> month. One month after spraying roofs, mortality of mosquitoes due to lambdacyhalothrin/ deltamethrin (P=2.56x10<sup>-5</sup>), lambda-cyhalothrin/DDT (P=1.2x10<sup>-7</sup>) and deltamethrin/DDT (P=0.013) were significantly different and this continued in the 2<sup>nd</sup> month. However, 3 months after spraying, mortality due to lambda-cyhalothrin/deltamethrin (P=1.46x10<sup>-6</sup>), lambda-cyhalothrin/DDT (P=0.048), and deltamethrin/DDT (P=0.004) were significantly different and this continued in the 4<sup>th</sup> month. Five months after spraying roofs, mortality due to lambda-cyhalothrin/ deltamethrin (P=0.000) and deltamethrin/DDT (P=6.6x10<sup>-7</sup>) were significantly different. Six months after spraying, lambdacyhalothrin/ deltamethrin (P=0.34), lambda-cyhalothrin/DDT (P=0.982), and deltamethrin/DDT (P=0.64) were not significantly different. When using exit window traps, no mosquitoes were collected from rooms sprayed with each of the insecticides over a 6-month period. However, 17, 6, 14, 7, 2 and 3 fed <em>An. gambiae sl </em>mosquitoes were collected in the 1<sup>st</sup>, 2<sup>nd</sup>, 3<sup>rd</sup>, 4<sup>th</sup>, 5<sup>th</sup> and 6<sup>th</sup> month respectively from unsprayed rooms and none of them died after 24 h.

2012 ◽  
Vol 44 (3) ◽  
pp. 19 ◽  
Author(s):  
N. Lukwa ◽  
S. Sande ◽  
P. Munosiyei ◽  
M. Zimba

Insecticide susceptibility tests using World Health Organization papers treated with 4% dichloro-diphenyl-trichloro-ethane (DDT), 0.05% deltamethrin, 0.05% lambda-cyhalothrin, 0.5% etofenprox, 0.15% cyfluthrin and 0.75% permethrin were conducted in Kamhororo, Masakadza and Chilonga villages, Zimbabwe. Three to 5-day old female <em>Anopheles gambiae sensu lato</em> adult mosquitoes were used. Deltamethrin knocked down 100% of the mosquitoes from Kamhororo, Masakadza and Chilonga at 35 min exposure. DDT did not knock down 100% of the mosquitoes from Kamhororo and Masakadza but did so in Chilonga. One hundred percent knockdown was achieved for cyfluthrin when exposed to mosquitoes from Kamhororo (60 min), Masakadza (25 min) and Chilonga (25 min). Etofenprox knocked down 100% of the mosquitoes collected from Kamhororo (30 min), Masakadza (30 min) and Chilonga (55 min). Knockdown of mosquitoes due to deltamethrin, DDT, cyfluthrin, permethrin; lambda-cyhalothrin and etofenprox were different at different observation times. One hundred percent mortality due to deltamethrin, DDT, etofenprox, lambdacyhalothrin and cyfluthrin was recorded for mosquitoes collected from all the 3 sites. One hundred percent mortality due to pemethrin was recorded for mosquitoes collected from Kamhororo and Chilonga but mortality was 98.5% for those collected from Masakadza. No knockdown or mortality occurred in the controls from each locality. The kd<sub>50</sub> (knockdown of 50% of the mosquitoes) values were 24.4-73.7 min (DDT), 8-13 min (pemethrin), 9.4-16.3 min (cyfluthrin), 9.4-14.4 min (etofenprox), 8.7-13 min (lambda-cyhalothrin) and 12.1-15.9 min (deltamethrin). The kd<sub>90</sub> (knockdown of 90% of the mosquitoes) values were 45.6-199.5 min (DDT), 14.7-26.5 min (pemethrin), 16.5-34.9 min (cyfluthrin), 21.8-24.4 min (etofenprox), 16.3-31.6 min (lambdacyhalothrin) and 21-25.3 min (deltamethrin). No insecticide resistance was recorded from the 3 sites.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Emmanuel Chanda ◽  
Alister Kandyata ◽  
Javan Chanda ◽  
Faustina N. Phiri ◽  
Lucy Muzia ◽  
...  

The selection of insecticide resistance in malaria vectors has the potential to compromise any insecticide-based vector control programme. To ensure that the insecticides used for indoor residual spraying and insecticide-treated nets in Zambia remain effective and their choice is evidence based, insecticide resistance surveillance and monitoring are essential. This study assessed and compared the residual efficacy of etofenprox (Vectron 20 WP), an ether pyrethroid, at 0.1 g/m2 with pyrethroids: bifenthrin (Bistar 10 WP) and lambda-cyhalothrin (Icon 10 CS) at 25 mg/m2 for indoor residual spraying. We also assessed the resistance status of etofenprox to local malaria vectors, An. funestus s.s and An. gambiae s.s, using World Health Organization standard protocols. The residual efficacy of Vectron 20 WP on cement, rendered walls of houses lasted for four months with 100% mortality. By the eighth month, the killing effect had reduced to 73.8% compared to 63.3% for bifenthrin and 77.0% for lambda-cyhalothrin. Susceptibility tests using standard World Health Organization assays on An. gambiae s.s showed susceptibility to etofenprox (0.1%) but some resistance was detected to Anopheles funestus s.s. The product is recommended as an ideal insecticide for indoor residual spraying for malaria control in Zambia as part of a resistance management programme in selected areas of the country.


2018 ◽  
Author(s):  
Tesfit Brhane Netsereab ◽  
Meron Mehari Kifle ◽  
Robel Berhane Tesfagiorgis ◽  
Sara Ghebremichael Habteab ◽  
Yosan Kahsay Weldeabzgi ◽  
...  

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