SINGAPORE - A total of 736 cases of dengue infection were reported in Singapore in the week of April 10 to 16 - the highest figure since the week of Aug 30 to Sept 5, 2020, when 937 cases were logged.
In contrast, during the week of April 11 to 17 last year, 112 cases were reported.
"Singapore is currently facing a serious dengue situation, and could see a major dengue outbreak this year," said the National Environment Agency (NEA).
It noted that the continuous sharp rise in cases this year comes even before the traditional peak dengue season from June to October.
As of Monday (April 18), there were 159 active clusters in Singapore, 33 of which had 10 or more cases.
More than 4,700 cases had been reported here as of April 16, with NEA saying it expects a surge in the coming months. Last year, a total of 5,245 cases were logged.
The agency said three main factors are driving this surge.
First, the recent warm, rainy and humid weather may have led to a high number of Aedes aegypti mosquitoes - which transmit the disease - in the community.
Second, the previously uncommon dengue virus serotype 3 is now circulating here, along with dengue virus serotype 2, which had contributed to the large outbreak here in 2019 and 2020.
Third, a proportion of people are still staying in and working from home. This leads to greater exposure to the mosquitoes, which feed in the day.
The authorities have taken several new steps to stem the spread of the disease.
These include a pre-emptive campaign targeted at those dealing with plants in the lead-up to Chinese New Year, bringing forward the launch of this year's national dengue prevention campaign, and mobilising agencies, MPs and leaders to heighten community awareness before the traditional peak dengue season.
NEA has also engaged the construction and pest control industries to help coordinate the stepping up of prevention measures, and introduced a purple banner to raise public awareness in areas with a persistently high population of Aedes aegypti mosquitoes.
In addition, Dr Wilson Tan, director of the vector biology and control division in NEA's Environmental Health Institute, said on Tuesday that Project Wolbachia will be expanded to cover 19 per cent of all Housing Board blocks here by the end of April.
The scheme involves releasing male mosquitoes carrying the Wolbachia bacterium in selected areas, so that when female Aedes aegypti mosquitoes mate with them, their eggs do not hatch.
The project has thus far shown encouraging results, said Dr Tan, but he added that it is not a silver bullet in the fight against dengue.
"We need to keep up with source reduction efforts to keep the Aedes aegypti population low," he added.
Source reduction refers to removing places where mosquitoes could potentially breed, such as roof gutters and empty flower pot plates.
The NEA said: "Concerted community action and sustained mosquito control efforts will prevent a further escalation of dengue cases, and help to avert a major dengue outbreak this year."