Good news is coming in from our field trial in Singapore. Last fall, we entered into a partnership with Singapore’s National Environment Agency (NEA) for the ongoing Project Wolbachia - Singapore to help reduce the population of ...
Good news is coming in from our field trial in Singapore. Last fall, we entered into a partnership with Singapore’s National Environment Agency (NEA) for the ongoing Project Wolbachia - Singapore to help reduce the population of Aedes aegypti. Over this past year we have been excited to see increasing suppression in our release areas as the program has grown to cover more residential blocks in the Tampines neighborhood of Singapore. As we close out the third phase of the field study and prepare to expand even further in Phase 4, we are happy to report that Project Wolbachia has achieved more than 90 percent suppression of the Aedes aegypti mosquito population in our release areas. Notably, in some of our release area blocks, we observed no female mosquitoes for multiple weeks at a time in the study traps.

Singapore’s high-rise and high density urban landscape presents a unique challenge to ensuring that the male mosquitoes we release are spread out effectively among different floors. For Phase 3, our collaboration treated 60 residential blocks, home to more than 22,000 residents, in Tampines West. We also deployed our mosquito sex-sorting technology, which has been successfully used in Debug Fresno and Debug Innisfail, to separate male and female mosquitoes using a computer vision algorithm and artificial intelligence.

16-story residential block 816 at the Tampines West release site under the Phase 3 and 4 phase study



As with all of our programs to date, we use a Wolbachia-based sterile insect technique. The male mosquitoes we release carry the bacterium Wolbachia and mate with urban female Aedes aegypti mosquitoes, that don’t have the bacterium. The resulting eggs from these matings do not hatch. Over time, the continued releases of sterile male mosquitoes, which cannot bite, gradually brings down the population of female Aedes aegypti, which can bite and spread diseases such as dengue and Zika. The NEA is exploring whether this mosquito population reduction can lower the risks of dengue transmission, which is a critical health issue in Singapore.

The Debug team will continue to carry out releases in an expanded release site in Tampines West in the next phase of the Project Wolbachia field study (Phase 4) in collaboration with the NEA. The expansion will double the release residential blocks to 121 and cover approximately 45,000 residents.

Map of Tampines West study site: green area = Phase 3 , dotted line area = Phase 4. Map provided by National Environment Agency.



We look forward to learning more about the effectiveness of continued release of sterile male Aedes aegypti mosquitoes through the expanded study site, as well as improving processes and release strategies in order to test new and innovative approaches to sustain a low Aedes aegypti population.




Yanni Yoong, Program Manager and Evdoxia Kakani, PhD, Senior Scientist, Verily



In November of 2018, our team was excited to announce that Debug Fresno 2018 utilized the sterile insect technique (SIT) to achieve a greater than 95% reduction in the number of biting female ...


In November of 2018, our team was excited to announce that Debug Fresno 2018 utilized the sterile insect technique (SIT) to achieve a greater than 95% reduction in the number of biting female Aedes aegypti mosquitoes in our release neighborhoods, relative to similar non-release sites. When we observed the data from traps in our release areas, we noticed that of the relatively few wild, female Ae. aegypti mosquitoes that were collected, many were along the edges of our release neighborhoods. This suggested that they were migrating over from non-release areas. Mosquitoes do fly, after all! What we observed suggested that, in order to achieve the strongest reduction in Ae. aegypti possible, we would need to expand the footprint of our release areas. Now back for our third season, Debug Fresno 2019 will soon begin releases over one of the largest areas ever treated with a Wolbachia-based SIT, increasing our release sites by two and a half times our previous season.

Our goal is to show that by releasing sterile male mosquitoes over large areas, we can minimize the edge-effects that were observed in 2018 and achieve an even stronger reduction in the local Ae. aegypti population. SIT has been used since the 1930s, and has been shown to be most effective when implemented in wide-area programs. While last year’s results provide a strong validation of Debug’s technology and approach, our goal is to ultimately scale our operations to intervene in broad areas where Ae. aegypti mosquitoes are established and, in some cases, are a serious burden to human health. For Debug Fresno 2019, we aim to drive down the local population of Ae. aegypti mosquitoes similar to last year’s strong results but over a larger area—which will be an important advance in bringing SIT to scale.

We have taken big strides with our work in Fresno over the past two years in collaboration with our partners at Consolidated Mosquito Abatement District and MosquitoMate, and we are gathering important knowledge on how to operationalize SIT. But there is more to learn! We look forward to continuing this study in Fresno County and learning more about how to defeat the devastating and invasive Ae. aegypti mosquito.




Jacob Crawford, PhD, Sr. Scientist, Verily