Abstract
Background: Dengue is reemerging in Laos and the most important recent outbreak was in 2013, with 44,098 cases. In 2019 (September), 27,904 dengue cases, including 54 deaths, were reported. Larviciding is one of the best options for larval control and in Laos, the organophosphate temephos has been the only larvicide used for vector control for decades. Recent studies showed that Aedes aegypti populations from Vientiane were resistant to this insecticide. In this context of dengue reemergence combined with high rates of urbanization, there was an urgent need to provide the public health authorities with new strategies, including new insecticides. We tested the efficacy of an innovative program using the auto-dissemination technique with the use of the In2Care® trap system in semi-field and large-scale field trials. Methods and materials: The auto-dissemination method using the pupacide insect growth regulator pyriproxyfen, was first investigated on the premises of the Institut Pasteur du Laos with 25 traps. This method was also implemented under large-scale field trials, in 2 dengue hotspots of Vientiane. In total, 600 traps were installed in 2 villages covering 1.2 hectares in each village. Aedes sp. densities were measured weekly with adult/larval traps and monthly with entomological indexes. Two other villages were selected as controls. Results: The small-field trial results showed a significant reduction of larvae and adult Aedes aegypti abundance during the treatment. The one year study in large-field trial has just finished and the results will allow us to test the hypothesis that Aedes densities measured weekly with adult/larval traps and monthly with entomological indexes, can decrease dramatically in the intervention zones vs. non-intervention zones. Conclusion: The results showed that the pyriproxyfen auto-dissemination strategy can represent an effective strategy to reduce mosquito densities in specific and determined areas and may represent a potential tool to be used in combination with other vector control strategies in Laos.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
