Additional 1,400 HDB blocks to get releases of male Wolbachia-Aedes mosquitoes from July 2022, bringing total coverage of the project to 31 per cent of all HDB blocks in Singapore and more than 300,000 households.

Singapore, 15 June 2022 – Minister for Sustainability and the Environment, Ms Grace Fu, announced at the Asia Dengue Summit today that NEA will be releasing male Wolbachia-carrying Aedes aegypti mosquitoes (Wolbachia-Aedes) in 1,400 additional HDB blocks across Singapore from July 2022. The releases are expected to reduce the urban Aedes aegypti mosquito population (dengue vector) in these high-risk areas, and help understand the impact of Wolbachia technology on dengue cases.

Eight new study sites to receive male Wolbachia-Aedes releases

2          NEA will expand the releases of male Wolbachia-Aedes mosquitoes to eight additional sites in a multi-site field study. The eight locations are Bedok (Bedok North and Bedok Reservoir), Choa Chu Kang (Yew Tee), Geylang, Hougang, Punggol, Sengkang and Woodlands (see Annex for Location Maps of Study Sites for NEA’s Multi-site Field Study). While the releases will suppress the urban Aedes aegypti mosquito populations in these sites, data collected will also help to determine the impact of the technology on dengue cases and clusters. The study has been scientifically designed, with the sites selected based on a set of criteria – historical dengue risk level, Aedes aegypti population, the size and landscape of the area, and NEA’s capacity for producing and releasing male Wolbachia-Aedes mosquitoes.

3          With this latest expansion, the coverage of Project Wolbachia-Singapore will increase from the current 19 per cent to about 31 per cent of total HDB blocks in Singapore. Five square kilometres of landed residential areas have also been covered. Selected construction sites and non-HDB residential sites in dengue high-risk areas will also see releases. Community and residents of release areas will be informed prior to the start of the releases.

Good results in current study sites; sustained releases still needed

4          Since April 2022, NEA has achieved full coverage of male Wolbachia-Aedes releases in Tampines and Yishun and started large-scale releases in the Marine Parade landed residential estate. High-risk areas in parts of Choa Chu Kang and Bukit Batok HDB towns will also continue to get targeted releases of male Wolbachia-Aedes mosquitoes. The results have been promising thus far. In Tampines and Yishun, where there has been more than one year of releases, we have previously observed up to 98 per cent reduction in the dengue mosquito population and up to 88 per cent reduction of dengue cases. Similar observations have been made in the current dengue outbreak where these areas have 70 per cent less dengue cases compared to similar areas without Wolbachia. The positive outcome of the field studies at release sites have shown that continued releases of male Wolbachia-Aedes mosquitoes can successfully suppress the female urban Aedes aegypti mosquito population in Singapore. 

Phased approach and testing different strategies help NEA in future wider scale deployment

5          As Singapore is the first country to trial and implement the use of this technology in a high-rise, high-density tropical environment, releases were first rolled out gradually in a phased approach, allowing for systematic and rigorous reviews. Carrying out different release strategies in different areas and landscapes also allows NEA to determine the most effective and impactful approaches for wider scale deployment.

6          When NEA first started Project Wolbachia in 2016, only 39 HDB blocks and over 3,900 homes were covered. Today, Project Wolbachia has covered about 1,800 HDB blocks across study sites in Yishun, Tampines, Choa Chu Kang and Bukit Batok towns, and within five square kilometres of landed estate at Marine Parade, comprising some 160,000 homes. With the multi-site field trial, over 300,000 homes will be covered.

7          “The expansion of the project to multiple sites is a very exciting and important next step in Project Wolbachia-Singapore. NEA is very encouraged by the results in existing study sites which have shown the effectiveness of the Wolbachia technology in the reduction of Aedes aegypti mosquito population in these areas. As Project Wolbachia successfully suppresses the population of dengue vector in release sites, the community is urged to cooperate with the programme in preventing the resurgence of mosquito abundance by removing mosquito breeding habitats. Having breeding sources of mosquitoes in the community will reverse the impact achieved by the technology” said Associate Professor Ng Lee Ching, Group Director, Environmental Health Institute, NEA.

Scaling up made possible by collaboration with partners

8          To support its project expansion, NEA will increase the number of male Wolbachia-Aedes mosquitoes produced per week from the current 2 million to 5 million by end 2022. Increased capacity for expansion of Project Wolbachia is made possible by NEA’s collaboration with our partners Orinno Technology Pte. Ltd. (Orinno), Verily Life Sciences (Verily) and the National Robotics Programme, that looks at the end-to-end development of differentiating robotic enablers and solutions in Singapore. Orinno co-develops technological solutions for the mass production, gender-sorting and release of male Wolbachia-Aedes mosquitoes using automation technologies and Artificial Intelligence. Such technological developments have improved the efficiency of mosquito production by up to 40 times, as compared to manual methods. Verily complements NEA’s mosquito production and release efforts and has contributed to the gender-sorting and release of male Wolbachia-Aedes mosquitoes at the Tampines and Marine Parade study sites.

Project Wolbachia – additional novel tool to fight dengue         

9        Against a backdrop of favourable climatic conditions, low herd immunity, presence of Aedes aegypti and endemic circulation of the virus, Singapore has experienced regular outbreaks. 2022 has been a challenging year thus far as we faced an early surge in dengue cases and numbers are expected to hit a record high, with more than 14,000 dengue cases reported to date, exceeding the total 5,258 dengue cases reported in 2021.  

10        The Wolbachia technology will complement existing community efforts and vector control operations to reduce the dengue vector in our community. The tool has been shown to be useful for reducing the risk of dengue transmission in a local area, typically taking at least three to four months to effect significant reduction of Aedes aegypti population. Moving forward, NEA will assess the use of the technology as an additional tool to interrupt active dengue clusters.

11        “Business-as-usual is not an option given the escalating threats of dengue. Novel technologies, including Wolbachia and dengue vaccines, provide new tools to complement and strengthen existing dengue control efforts, and prevent epidemic transmission of this disease. The results observed with Project Wolbachia to date are promising, but it is important for the Singapore community to realise that it is not the silver bullet that will control dengue alone. It is thus important for the community to continue staying vigilant and take steps to fight dengue,” said Professor Duane Gubler, Dengue Expert Advisory Panel Chairman and Emeritus Professor at Duke-NUS Medical School, Singapore.

Community to continue staying vigilant and take steps to fight dengue

12        Even as we roll out Project Wolbachia-Singapore to more areas, the technology is not a panacea and its effectiveness may be hindered by mosquito breeding in the community. Residents and businesses throughout the country, with or without Wolbachia-Aedes releases, must ensure good housekeeping to keep our homes, premises and estates free from mosquitoes and dengue. We seek everyone’s support to stay vigilant and do their part to prevent dengue.

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ANNEX

Location Maps of Study Sites for NEA’s Multi-site Field Study

Bedok North

Bedok Reservoir

Choa Chu Kang (Yew Tee)

Geylang

Hougang

Punggol

Sengkang

Woodlands