Wolbachia-Aedes Mosquito Suppression Strategy

Field Study to Test Targeted Release Strategy

Field study to test targeted release strategy

Targeted release strategy in HDB estates

In May 2020, NEA expanded releases of male Wolbachia-carrying Aedes aegypti (Wolbachia-Aedes) mosquitoes to selected dengue high-risk neighbourhoods in Choa Chu Kang, Keat Hong, and Hong Kah North. These neighbourhoods were selected due to their consistently high Aedes aegypti mosquito populations.

This targeted approach, which zeroes in on high-risk areas, differs from the “rolling” approach adopted in Yishun and Tampines, where release sites were gradually expanded to adjacent neighbourhoods.  

Release schedule

Preliminary findings

Ongoing releases in parts of Choa Chu Kang, Keat Hong and Hong Kah North constituencies have reduced the urban Aedes aegypti populations, with most areas having fewer than 10 mosquitoes caught per 100 traps per week. The heat map below shows the “eraser effect”, where previously dark red areas (indicating high Aedes aegypti mosquito population) gradually faded to low mosquito population from May/June 2020 to April 2021. 

With the promising results, NEA will continue to expand and carry out releases at other high-risk areas in Choa Chu Kang and Bukit Batok towns by end 2021. The targeted strategy in these areas remain unchanged, which means releases will be conducted on pockets of areas with perennially high Aedes aegypti mosquito populations and persistent dengue transmission. 

Targeted Release Strategy_preliminary results

 

Targeted release strategy in landed estate

Following the good results of Project Wolbachia in high-rise residential HDB estates, NEA will additionally expand releases to the Marine Parade landed estate area. NEA has been engaging residents, and have recruited volunteers to host different mosquito traps in their homes for mosquito surveillance. From Q4 2021, vans equipped with release automation technology will be deployed to conduct targeted small-scale releases at the Marine Parade landed estate area. Data gathered will help guide deployment for larger scale releases at the area. 


Targeted release strategy in construction sites

As part of the expansion, releases will also be carried out at construction sites within the study sites. NEA is working with relevant stakeholders, including construction companies, to guide them on the surveillance and release of male Wolbachia-Aedes mosquitoes at such premises. This is part of our strategy to achieve better suppression at the study sites, by covering different terrains and landscapes.