Twenty-two new dengue clusters have emerged over a period of two days, bringing the total number as of Wednesday to 108.
This is a 25 per cent increase over the 86 clusters reported on Monday.
Dengue infections have been rising over the past two weeks, following five weeks of declining figures.
There were 313 reported dengue infections last week. Between Sunday and 3pm on Wednesday, another 189 people had been diagnosed with the viral disease.
The current outbreak appears to be quite severe, with 20 people dying after more than 16,100 fell ill from the viral infection last year.
The 88 people who had the more severe dengue haemorrhagic fever last year amounted to more than quadruple the previous five-year median of 20 such cases a year.
About one in five people diagnosed with dengue requires hospital care.
The infections appear to be spread islandwide, although there is a slightly higher concentration in the north and the east.
The biggest cluster is in Pasir Ris, with 153 cases. Of these, almost a third are in the parallel roads of Riverina View and Riverina Crescent.
Other big clusters include two in the Yio Chu Kang area, one with 134 people infected and the other with 129 cases.
The National Environment Agency (NEA) is concerned about increased mosquito breeding in view of the coming Chinese New Year as "homes and other premises will be decorated with more ornamental plants".
On its dengue website, it urged people to "take care of these plants and prevent them from becoming mosquito breeding habitats by making sure water does not gather in the flowerpot plate or on the soil".
The dengue virus is spread by the female Aedes mosquito when it bites an infected person and then goes on to bite others.
The Aedes mosquito does not need much water to breed. A small amount, the size of a 20-cent coin, is enough. One female mosquito can lay 300 eggs in its lifetime.
The NEA added: "Home owners doing spring cleaning are also reminded to properly dispose of any refuse, including large furniture or household items, to avoid the discarded materials from becoming unintentional mosquito breeding habitats."
Symptoms of dengue include fever, joint ache, nausea and vomiting, headache and rash. In more severe cases, a person may bleed from the nose or gums.