The number of Aedes aegypti mosquitoes, which are responsible for dengue, has been growing, renewing concerns about the potential for a flare-up in the disease after last year saw the lowest number of cases in 16 years.
Minister for the Environment and Water Resources Masagos Zulkifli said yesterday that the National Environment Agency (NEA) detected 22 per cent more Aedes aegypti mosquitoes in the first three months of this year compared with the previous three months.
The NEA monitors the mosquito population here through the use of gravitraps - black cylindrical devices - which are placed along the corridors of residential buildings.
"It shows that as much as we do to bring down the breeding, there is a role for everyone to not allow the breeding to happen, particularly at home," Mr Masagos said.
"We must be extra vigilant, especially since we are approaching the traditional peak dengue period," he added.
The warmer months of June to October usually see higher transmission of dengue due to accelerated breeding and maturation cycles of the mosquitoes, and shorter incubation periods for the dengue virus.
Mr Masagos noted: "One misconception in particular is that mosquitoes will not breed in clean water. That is not true... Any stagnant water can attract mosquitoes to breed."
There have been four dengue deaths so far this year, with three victims living in an active dengue fever cluster in Jurong West.
Mr Masagos, who launched the National Dengue Prevention Campaign yesterday at an open field beside Block 270A Punggol Field, said that NEA has stepped up checks, conducting about 265,000 inspections, including 2,400 at construction sites, from January to March this year.
About 4,200 mosquito breeding sites were uncovered. About 100 notices to attend court and six stop-work orders were issued. Nine court prosecutions were also launched.
NEA found that many homes continued to be breeding mosquitoes even as the situation at construction sites had improved - dropping from 11 per cent of such sites in 2013 to 6 per cent last year.
Some 70 per cent of the breeding in the Jurong West cluster, for instance, was found in homes. Some breeding spots had up to 200 larvae each.
Currently, home owners face a $200 fine if found to be breeding mosquitoes. There are no plans to raise the penalty, Mr Masagos said.
The annual dengue prevention campaign will have grassroots advisers, leaders and volunteers conduct patrols to check for mosquito breeding, as well as make house visits to educate residents on how to prevent the spread of dengue.
Yesterday, Ms Sun Xueling, Senior Parliamentary Secretary for Home Affairs and National Development and an MP for Pasir Ris-Punggol GRC, visited homes in 13 blocks with volunteers.
One resident, bank analyst Lim Jun Wei, 33, said: "It is quite scary that a bite from a mosquito can kill. The deaths have made us more aware (of the need) to take preventive steps."