SINGAPORE - Residents may go for holidays but mosquitoes do not take a break from breeding in their absence.
Uncovered toilet bowls and gully traps as well as roof gutters that have not been cleared are some ways mosquitoes exercise "creativity" in finding new breeding spots.
The Minister for the Environment and Water Resources cited this as an example of the importance of individual and collective efforts to fight dengue.
Responding to a question from Non-Constituency MP Yee Jenn Jong, Dr Vivian Balakrishnan said a change in the predominant dengue virus serotype is one factor behind the latest epidemic.
There are four strains of the dengue virus. When a person is hit by one, he develops immunity only to that and remains vulnerable to the other three.
Hence, a change in the predominant virus serotype increases the chances of an epidemic as the population has lower immunity against the new strain.
In 2005, for instance, Singapore experienced its worst dengue outbreak when the predominant serotype switched from Den-2 to Den-1.
Two years later, a smaller outbreak occurred when the reverse happened.
In 2005, there were 14,209 dengue cases and 25 deaths.
In 2007, 8,826 people came down with dengue and 20 died.
In the last two months, more cases of the Den-1 and Den-3 strains have emerged. "This potential change in the serotype has contributed to this latest spike in dengue cases," said Dr Balakrishnan.
About 1,800 people have been diagnosed with the illness this year, compared to fewer than 600 in the same period last year.
Replying to Mr Yee's question on what is being done to counter the threat, particularly in the hot spots in Telok Kurau and East Coast Road, he said the National Environment Agency has been working closely with local grassroots groups to educate residents on what to do.
Inspections have been stepped up under an inter-agency task force which looks for breeding sites in public outdoor spaces.
Last year, 900 mosquito- breeding offences were detected in construction sites, of which 626 were first-time offences.
As of Monday, there were 33 active dengue clusters.
The Poh Huat and Park Villas vicinity - the worst-hit cluster - had 72 cases in all.
At Terrasse Lane alone, there were 29 cases.
Dengue symptoms include sudden fever, aching joints, headaches, rash and nausea.
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