Close to 5,500 dengue cases have been reported in Singapore so far this year, exceeding the total number of cases recorded in the whole of last year, said Minister for Sustainability and the Environment Grace Fu on April 24.

A total of 5,258 cases were logged last year.

The week ending last Friday saw 746 dengue infections. This is the highest seven-day figure since the week of Aug 30 to Sept 5 in 2020, when 937 cases were reported.

“This is a worrying trend as we are only in April, and we expect a surge in the number of dengue cases in the coming months,” said Ms Fu at the launch of the 2022 edition of the Public Hygiene Council’s Keep Clean, Singapore campaign.

The National Environment Agency (NEA) has said that Singapore is facing a serious dengue situation and could see a major outbreak this year.

The continuing sharp rise in cases comes before the traditional peak dengue season from the mid-year to October. As at last Friday, there were 180 active dengue clusters, with six of them recording more than 100 cases.

The largest cluster - at 294 cases since it emerged - is in the Holland Road vicinity, including Grove Avenue and Mount Sinai Avenue.

NEA said the surge in cases this year is due to three factors. First, the recent warm, rainy and humid weather may have led to a high number of Aedes aegypti mosquitoes in the community.

Second, the previously uncommon dengue virus serotype 3 is now circulating in Singapore, along with dengue virus serotype 2, which contributed to the large outbreak in the city-state in 2019 and 2020.

In 2019, 15,998 cases were reported. That number more than doubled in 2020.

Third, a proportion of the workforce is still working from home, leading to greater exposure to the mosquitoes, which feed in the day.

Ms Fu said the number of cases is rising very alarmingly, and everyone needs to help battle dengue.

She reminded residents to keep up with good housekeeping to prevent mosquito breeding.

This includes emptying flowerpot plates, overturning pails and wiping their rims, and keeping roof gutters clear.

She also reminded people to bin their trash to prevent it from becoming an unintentional mosquito-breeding habitat if strewn on the ground.

“Dengue is a serious health threat. Let us stay on guard against dengue even as we see improvements in the Covid-19 situation,” added Ms Fu.

Dengue cases soared to a record high of 35,315 in 2020, as more people stayed home because of Covid-19. There were 50 per cent more dengue infections during the circuit breaker in April and May that year, compared with the same months in previous years.

More mosquito breeding in homes was also detected that year, perhaps due to initial challenges faced by residents in juggling working from home, higher housekeeping loads and home schooling, said NEA in a statement then.

The following year, cases fell to around 5,200 due to cross-protective immunity caused by the two-year outbreak in 2019 and 2020.

However, cross-protective immunity against other serotypes - such as the less common serotype 3 - was short-lived, leading to weekly dengue cases rising again since the end of last year.

Family physician Quah Soon Wee of Crossroads Family Clinic in Tampines said most infected people remain well, with proper rest, hydration, and fever medication.

“If they develop severe symptoms such as severe abdominal pain, vomiting, bleeding from gums or nose, they should seek medical advice immediately.”