More mosquitoes, more cases expected in warmer months ahead: NEA

Channel NewsAsia 20 May 18;

SINGAPORE: The mosquito population is expected to increase along with the number of dengue cases in the warmer months ahead, the National Environment Agency (NEA) said in a media release on Sunday (May 20).

Through its Gravitrap surveillance system, NEA said it found that the mosquito population remained high with 22 per cent more Aedes aegypti mosquitoes in the first quarter of this year compared to the previous quarter, thus posing a risk of an increase in dengue cases.

Earlier this month, three people died and 60 dengue cases were reported in a dengue cluster at Jurong West.

"The warmer months of June to October usually see higher transmission of dengue in Singapore, due to accelerated breeding and maturation cycles of the Aedes mosquitoes and shorter incubation periods for the dengue virus.

"NEA is thus expecting an increasing trend in cases in the warmer months ahead if we do not take steps to keep the mosquito population in check," the media release said.

The agency urged members of the public to continue to work together as a community to stem dengue transmission.

"NEA, together with the various agencies and other stakeholders represented in the Inter-Agency Dengue Task Force (IADTF), including Town Councils, have stepped up checks leading up to the traditional peak dengue season to rid our public areas and housing estates of potential mosquito breeding habitats," added NEA.

From January to March 2018, NEA conducted about 265,000 inspections, including 2,400 inspections carried out at construction sites, the agency said, adding that it uncovered about 4,200 instances of mosquito breeding habitats.

Speaking at the main launch of the 2018 National Dengue Prevention Campaign at the North East District on Sunday, Minister for the Environment and Water Resources, Masagos Zulkifli urged all members of the public and stakeholders to stay vigilant and not let their guard down even though the dengue cases this year are fewer than in recent years.

He made the call for a concerted effort to suppress the Aedes mosquito population and keep dengue incidence low in the run up to the peak dengue season.

PROJECT WOLBACHIA

Meanwhile, NEA said Phase 2 of the Project Wolbachia study has also begun. The study is being conducted at the same Phase 1 sites (Tampines West and Nee Soon East) and their extended areas, the agency added.

The project involves the use of Wolbachia-infected mosquitoes to suppress the Aedes aegypti mosquito population in Singapore.

So far, the study has provided "valuable ecological information" on the behaviour of mosquitoes in Singapore, NEA said.

The Phase 2 study is expected to build on that and improve the release methodologies in Singapore's high-rise and high-density urban environment, the release added.

"While NEA explores the potential of Wolbachia technology, source eradication of mosquito breeding habitats and spraying of insecticides where necessary to control the adult mosquito population, will continue to be our key strategy for dengue prevention in Singapore."

The dengue prevention campaign launch will be followed by island-wide outreach efforts across the five districts at different constituencies, NEA said.

This campaign will be supported by the local grassroots advisers and the community, with the mobilisation of grassroots leaders and Dengue Prevention Volunteers (DPVs).

They will conduct patrols to check for potential breeding habitats in common areas around their neighbourhoods and house visits to advise residents on common mosquito breeding habitats and to share dengue prevention tips, the release said.

The campaign this year will focus on making residents aware that clean and stagnant water in their homes can be potential breeding habitats for mosquitoes, it added.

Source: CNA/mn


Renewed dengue concerns after NEA detects rise in Aedes mosquito population
Samantha Boh Straits Times 20 May 18

SINGAPORE - The number of Aedes aegypti mosquitoes, which is 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 Zulkifi said on Sunday (May 20) that the National Environment Agency (NEA) detected 22 per cent more Aedes aegypti in the first three months of this year compared to 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 on Sunday at an open field beside 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 six per cent in 2017.

Some 70 per cent of the breeding in the Jurong West cluster, for instance, were found in homes. Some breeding spots had up up to 200 larvae each.

On Sunday, Ms Sun Xueling, senior parliamentary secretary for the Ministry of Home Affairs and the Ministry of National Development, and MP for Pasir-Punggol GRC, visited homes in 13 blocks with volunteers to educate residents on dengue prevention.

One resident, bank analyst Lim Jun Wei, 33, said: "It is quite scary that a bite from a mosquito can kill. The deaths has made us more aware and to take preventive steps."