Oral Reply to Parliamentary Question on Dengue and Project Wolbachia

Question:

Mr Ang Wei Neng: To ask the Minister for Sustainability and the Environment (a) what are the major reasons for the sharp decline in the number of dengue cases reported in 2025; and (b) when will the Project Wolbachia trial be extended to all the towns in Singapore.

Answer:

4,036 dengue cases were reported in 2025, which was the lowest number since 2018. An absence of major large outbreak locally, the global decline in dengue cases in 2025, and concerted efforts by all stakeholders and residents in Singapore to control the mosquito population, collectively contributed to the decrease. NEA’s holistic dengue control strategy, which combines Project Wolbachia, vector control operations, and action by all to keep premises free of mosquito breeding, continues to help keep dengue incidence low.

By March 2026, Project Wolbachia will be expanded to cover 740,000 households, up from 580,000 households in April 2025. By end-2026, Project Wolbachia releases will cover 800,000 households, or 50 per cent of all households in Singapore, covering the majority of areas at risk of large dengue outbreaks. NEA will continue to monitor the progress of Project Wolbachia and adjust its deployment strategy.

Reducing dengue risks in our community requires the cooperation and support of residents. We seek residents’ understanding that more mosquitoes may be seen during the release periods of male Wolbachia-carrying mosquitoes, but these mosquitoes are necessary to help suppress the Aedes Aegypti population and do not bite or transmit disease.