There's a buzz in Bukit Batok - of the deadly kind.
The estate is home to the biggest dengue cluster Singapore has seen in the past nine years.
The 34 blocks at Streets 31 to 34 have registered 96 cases since the cluster started two months ago. .
It is also home to the hottest dengue block - Block 225 at Bukit Batok Central had 10 cases.
Madam Jamilah Aris, 47, a sewing and cooking instructor at the Residents Committee office at Block225, said: 'Dengue is a concern especially since there are primary school students who come here every day for tuition.'
In total, Bukit Batok has had 21 dengue clusters and almost 250cases this year.
So what makes this area so dengue-prone?
One reason is that it's in the west, where residents generally have lower immunity compared to those in the east because dengue has only recently moved into the western part of Singapore.
But there are other housing estates in the west that are not as badly hit.
Could it be due to some outdoor breeding spots which have been overlooked by the authorities?
In the past two months, Hong Kah Town Council has been fined $1,200 for six cases of mosquitoes breeding in places such as drains and carparks.
MrAng Mong Seng, an MP for Hong Kah GRC, has said that the large area under the council's charge, with 800residential blocks, made it hard at first to eliminate all the breeding spots.
But checks have since been stepped up, with the number of council officers combing public areas doubling from five to 10 and the council's pest control contractor inspecting daily.
Unlike the fishing pond pump room in Pasir Ris Drive6 which had over 600 larvae - the likely cause for the outbreak there - no major outdoor breeding spot in Bukit Batok has been found so far.
Intensive operations
When the National Environment Agency (NEA) carried out its third round of intensive operations last weekend, only one of the 23 breeding spots found were outdoors.
Forty officers, double the number from the last round of operations, inspected 34 blocks at Bukit Batok Street 31, 32 and 34 over three days, looking into residential premises and places like pump rooms, bin centres and rooftops.
NEA also checked surrounding blocks outside the cluster area as a buffer.
They found 22 breeding spots in homes, continuing the trend in this cluster where the vast majority of breeding spots are indoors.
There was one case where several hundred larvae were found in a single container.
Out of the 63 breedings detected in this area since the cluster started, 87 per cent (55) were in residential premises, in the usual spots like pails and vases.
The availability of indoor breeding spots favours the Aedes aegypti mosquito, which likes to breed indoors.
It's no wonder that Aedes aegypti numbers in the area have skyrocketed from 1 per cent of the area's Aedes mosquito population in 2003 to a whopping 66 per cent this year.
Compared to Aedes albopictus, which tends to breed outdoors, Aedes aegypti is the main culprit of large dengue outbreaks because it feeds on several people.
This results in a wider transmission of the dengue virus within a shorter period of time.
When there's a large dengue cluster, there is also a vicious circle effect, warns NEA.
As the cluster grows, the pool of infected residents, also known as the virus reservoir, becomes bigger.
With a bigger reservoir, the probability of a mosquito biting an infected person is higher, resulting in further transmission of dengue.
What all this means is that Bukit Batok residents have to be even more vigilant if they want their area to stop being known as Singapore's dengue central.
Housewife Ma Meng Lan, 55, who lives in Block364 Bukit Batok Street31, said in Mandarin: 'I know dengue is a problem around here. I do make sure there is no stagnant water in my home.'
NEA said: 'Residents play a very important role in breaking the transmission cycle within the cluster by taking the necessary precautionary measures to prevent breeding in their homes and apply mosquito repellent to prevent being bitten by mosquitoes.'
Fast facts
- The majority of breeding spots were indoors
- The indoor breeding areas included pails and vases
- Block 225 at Bukit Batok Central alone had 10 cases
- The numbers of Aedes aegypti in the area have increased from 1 per cent of the area's entire Aedes population to 66 per cent this year. This Aedes breed is the main culprit of dengue outbreaks
