Cases of dengue fever, a disease spread by infected mosquitos, are now mounting in the city-state, which has already reported 14,000 of them so far this year.
Health officials now believe that number is almost certain to exceed the 22,170 cases reported in 2013, the previous-worst outbreak, by the end of the year.
Last week 1,468 cases of the virus were reported, the third consecutive week that cases have exceeded 1,000 and the largest weekly total ever recorded in Singapore.
Sixteen people have died of the virus, Singapore reports, compared to 26 who have died from coronavirus. Singapore has 44,479 cases of coronavirus.
Those figures are expected to get progressively higher as the state moves deeper into mosquito breeding season, which began in June and lasts until October.
Like coronavirus, only around 25 per cent of those infected by dengue - which is spread by the bite of the Aedes mosquito - will show symptoms.
Also like coronavirus, dengue has an incubation period of between five and ten days after a person is bitten, with symptoms lasting around a week.
Symptoms are also similar to coronavirus, including high fever and muscle pains. Other symptoms include vomiting and headache, particularly behind the eyes.
A small number of cases develop severe symptoms, which include vomiting blood, rapid breathing, severe abdominal pain and fatigue.
Dengue has a mortality rate of around one percent of cases, which is similar to coronavirus - which is thought to have a mortality rate of around 1.5 percent.
Health authorities say Singapore currently has 334 active dengue clusters around the city, driven by 'profuse mosquito breeding'.
Inspectors say people failing to remove patches of stagnant water - including outdoor basins, disused water features, jacuzzis and drains - has led to the spike.
In several cases, they said numbers of mosquito larvae discovered in such places were 'too numerous to count' and easily exceeded 100.
Starting on July 15, the government will increase fines for people who fail to properly remove stagnant water, which the mosquitos use to breed.
The fresh crisis comes amid the outbreak of coronavirus in Singapore, which is one of the most severe in southeast Asia.
The country was one of the first to be affected with coronavirus outside mainland China, and was initially praised for its world-beating response.
By March 28, the peak of Singapore's first wave and three months after first infection, the city-state hand managed to keep new cases to just a few dozen per day.
But then the outbreak spread to Singapore's migrant workers, who live in overcrowded largely unsanitary housing, and cases soared.
During the peak of its second wave, on April 21, officials logged 1,426 cases in a 24 hour period.
By comparison, neighboring Malaysia has reported 8,648 cases, though a significantly higher number of deaths at 121.