Project Title: Assessment of mosquito biting reduction and mortality rates caused by eave-ribbon treated with different formulations of transfluthrin inside the semi-field system
Project Description: Short description of the Project/Consultancy/Platform: This project study will assess the efficacy of eave ribbons treated with two different formulations of transfluthrin (Emulsified concentrate EC-200 and Capsule suspension CS200) for protection against indoor and outdoor-biting malaria mosquitoes as well as mortality and survival rates of mosquitoes exposed to these different formulations of transfluthrin. Furthermore, to confirm the safe use for residents living in houses being protected by transfluthrin treated eave ribbons. Vapor concentrations of transfluthrin... Short description of the Project/Consultancy/Platform: This project study will assess the efficacy of eave ribbons treated with two different formulations of transfluthrin (Emulsified concentrate EC-200 and Capsule suspension CS200) for protection against indoor and outdoor-biting malaria mosquitoes as well as mortality and survival rates of mosquitoes exposed to these different formulations of transfluthrin. Furthermore, to confirm the safe use for residents living in houses being protected by transfluthrin treated eave ribbons. Vapor concentrations of transfluthrin inside experimental huts placed inside the semi-field system will be determined. In addition to get a better basis for the exposure risk assessment of operators. Transfluthrin concentrations in the breathing zone of the operator will be determined when performing the spray treatment. The overall objective is to assess the entomological efficacy (biting reduction, 24-hour mortality) of eave-ribbons treated with different concentrations and formulations of transfluthrin inside the semi-field system, as well as to assess their safe use for residents and operators. Specific objectives 1. To assess mosquito biting reduction indoor and outdoor offered by the eave-ribbons treated with different formulations and concentrations of transfluthrin (outcome measure: number of mosquitoes landing outside and inside huts fitted with or without the transfluthrin-treated eave ribbons) 2. To assess 24-hour mortality of mosquitoes exposed to the eave-ribbons treated with different formulations and concentrations of transfluthrin (outcome measure: proportion of mosquitoes dead within 24hrs after exposure to huts fitted with or without the transfluthrin-treated eave ribbons) 3. Assess the concentrations of transfluthrin in air in experimental huts fitted with treated eave ribbons. 4.' Assess the concentration of transfluthrin in the breathing zone of operators when treating eave ribbons. The eave ribbon is a double layer ribbon consisting of two pieces of hessian. The final dimensions of the eave ribbon are 0.15m and 11.6m, consisting of a treatable area of 2 x 1.7 m 2 = 3.4 m 2 . Both sides of the eave ribbon are treated. Treatments of the ribbons will be done by using a Hudson backpack sprayer, calibrated to ensure constant application of chemical on the ribbons (see appendix 3 for details on sprayer calibration). Separate sprayers will be used for control and treatment to ensure there is no contamination of the control. Before treatment of the eave-ribbons, amount of solution needed to treat ribbons will be determined by spraying the ribbon with water to estimate the right amount of solution needed to treat one set of the eave-ribbon without dripping and time needed for treatment will be noted. We will prepare our treatment transfluthrin formulations as follows: 2g Im2 EC-200 on each side of the eave ribbon (4 g/m2 in total) 9g Im 2 CS-200 on each side of the eave ribbon (18 g/m2 in total) 9g /m2 EC-200 on each side of the eave ribbon (18 g/m2 in total) Water as control The sprayed on one side of the ribbons using the pressurized sprayer with eave ribbons laid on tin foil on the floor according to the time measured before and the sprayer will be weighed again. The control eave ribbons will be sprayed with water only. Treated ribbons (one side only) will be dried under shade, then rolled and packed in foil the placed in clean and labelled plastic bags ready for the experiment, they will not be stored in plastic bags for more than 2 hours. Treated and untreated ribbons will be fitted on the eave spaces using nails and pieces of copper wire with treated side facing the wall. They will be installed in a way that they will not touch the wall of the huts, to prevent contamination, and also so that they do not seal the eave spaces. The sprayer will be weighed before treatment and the untreated side of the ribbon will be sprayed in situ with the respective prepared solution according to the time measured before and the sprayer will be weighed again. This study will be conducted inside the semi-field facilities at the Mosquito City facility of the Ifakara Health Institute with a total surface area of 552.96m 2 . The facility is located in Kining'ina Village, -6km north of Ifakara town, in south-eastern Tanzania. We will use 2 screen houses each with six chambers measuring 9.6 m long x 9.6 m wide x 4.5 m high. The ribbons will be fitted to experimental huts measuring 3.1 m x 2.7 m constructed inside the different chambers.
Principal Investigator : Fredros Okumu
Department Name :
Time frame: (2020-07-10) - (2025-07-10)
Bayer AG (Normal)
External Collaborating Partners
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