A 71-year-old woman died from dengue fever last month, the third dengue-related death this year.
The woman, who lived in Ang Mo Kio Avenue 4 - previously an active dengue cluster - died on March 23, a Ministry of Health (MOH) spokesman said on Thursday.
Two men, aged 74 and 77, died from dengue fever in February. One of the deaths took place in an active dengue cluster in Bedok. The other occurred in Hougang.
Latest figures from the National Environment Agency (NEA) website showed there were at least 2,224 cases of dengue fever reported so far this year.
As of Monday, NEA noted that there were 26 active dengue clusters, with the three largest located in Woodlands, Teck Whye Lane and Serangoon Gardens. The Woodlands cluster comprises Woodlands Circle, Woodlands Crescent and Woodlands Drive 60, while the Serangoon Gardens cluster includes Golden Walk, Tai Hwan Avenue and Tai Hwan Crescent.
A total of 101 dengue cases were reported for the whole of last week, four more than the 97 for the week before. There were 109 cases during the March 10-16 period.
NEA said its Gravitrap surveillance system detected about 40 per cent more Aedes aegypti mosquitoes in December last year, compared with December 2017. Gravitraps are traps that catch such mosquitoes and collect data on them.
"If not reduced, the high Aedes aegypti mosquito population may lead to a surge in dengue cases in 2019," the agency said, adding that the public should stay vigilant.
Last year, five people aged 41 to 75 died from dengue fever. There were 3,285 reported cases of dengue last year, almost 20 per cent more than in 2017.
Meanwhile, MOH said there have been four Zika cases this year - two local infections and two imported cases. All four people have recovered after seeking outpatient treatment.
The ministry said sporadic Zika cases will be detected from time to time as Singapore is a travel hub and remains vulnerable to the importation of the Zika disease.
"We are also susceptible to Zika virus transmission because it is primarily transmitted to humans via the bite of an infective Aedes mosquito, a common species found locally that also transmits the dengue virus," an MOH spokesman said.
"Singaporeans should remain vigilant at all times and continue to do our part to prevent mosquito breeding in homes and workplaces."