Residents of Housing Board blocks across Yishun and Tampines may notice more mosquitoes in the coming weeks. But these ones are not out for blood.
As part of Project Wolbachia, the National Environment Agency (NEA) will release specially bred mosquitoes across all 1,455 HDB blocks in these two towns, which roughly account for 15 per cent of all HDB blocks in Singapore.
The project expansion across all of Yishun and Tampines is slated to be completed by March 2022.
These specially bred, male Aedes aegypti mosquitoes carry the Wolbachia bacterium. After mating with their female counterparts, the resulting eggs do not hatch, thus suppressing their population.
Wolbachia-Aedes mosquitoes were first introduced at test sites in Yishun and Tampines in 2016, and NEA found that it led to a marked fall in the mosquito population.
As of May this year, about two mosquitoes are caught each week for every 100 Gravitraps in some areas, a significant decrease from roughly 20 to 30 mosquitoes per week for every 100 Gravitraps back in November last year.
The fall in the mosquito population translates to a reduced incidence of dengue, according to Associate Professor Ng Lee Ching, director of NEA's Environmental Health Institute.
"These encouraging preliminary results from the study sites give us confidence to extend releases to more areas," Prof Ng said, adding that NEA aims to eventually reduce the number of Wolbachia-Aedes mosquitoes released.
The expansion of Project Wolbachia is meant to complement NEA's current vector control efforts to curb the spread of dengue during this year's particularly bad outbreak.
There have already been a total of 17,249 cases of dengue fever as of Monday afternoon, exceeding last year's total of 15,998 cases.
At least 16 people have died from dengue so far this year.
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PROJECT WOLBACHIA
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2
HDB towns involved - Yishun and Tampines
1,455
Number of HDB blocks rolled out to
2022
Completion date
The surge in cases this year has been driven by several factors, including the initial surfacing of a less frequently seen dengue strain, as well as rain and warmer temperatures.
The circuit breaker measures to fight Covid-19 may have also contributed to the rise in cases. The Aedes aegypti mosquito bites in the day, so more people staying home could have led to increased numbers of infections.
While these measures were lifted a month ago, the number of dengue cases continues to increase.
Members of the public are reminded by NEA to remain vigilant and continue following preventive measures, such as the five-step mozzie wipeout, in order to prevent mosquito breeding.
