More Wolbachia mosquitoes to be released in an extended test area: NEA

SINGAPORE — Wolbachia-infected mosquitoes will be released around more Housing and Development Board (HDB) flats in Nee Soon East and Tampines West, as the National Environment Agency (NEA) continues its study on a technology that can help the country control the spread of dengue.

The number of HDB blocks involved will be doubled to 144 when Phase Three of its study begins next month, the agency said on Wednesday (Jan 30).

When Wolbachia-infected male mosquitoes mate with female Aedes mosquitoes, they will produce eggs that do not hatch.

Through this, NEA hopes to bring down the population of Aedes mosquitoes to prevent the spread of dengue.

In the second phase of the study, the population of Aedes mosquitoes in Nee Soon East was suppressed by about 80 per cent, NEA said.

The other study site in Tampines West had a less satisfactory result, suppressing the Aedes mosquito population by half.

This could be attributed to the discovery of 10 Aedes mosquito breeding sites in Tampines between September and December last year.

“We’re learning as we are going along. This is all part of our learning curve,” said Laureate Professor Ary Hoffmann, a member of the Dengue Expert Advisory Panel.

“We know if we can get the population down, we can then pull back on the number of mosquitoes we release.”

In the upcoming phase, researchers will explore an optimum ratio of Wolbachia-infected mosquitoes to release, in order to keep the Aedes mosquito population in the area low. They will also vary the number of mosquitoes released at different points of the study site.

Male mosquitoes do not bite, hence the mosquitoes released by NEA will not transmit any diseases or pose any health risks. They live only for up to a week as well.

The mosquitoes will be released around blocks and along common corridors, and not in homes, said NEA.

Outreach activities such as distribution of information booklets or door-to-door engagement will take place after Chinese New Year, ensuring that residents are aware of this project before it commences.

NEA can be contacted at 1800-2255-632 if the public has any enquiries or feedback on this project.