SINGAPORE – A total of 30,969 dengue cases have been reported here so far in 2022, as at last Friday – almost six times that of the whole of 2021.

Weekly figures also remain high, leading the authorities to warn that the elevated numbers could portend another outbreak in 2023.

In an update on the dengue situation on Monday, the National Environment Agency (NEA) said that although weekly dengue cases had declined by about 80 per cent from the peak in May, when they hit a high of 1,568, the current tally of between 200 and 300 new cases each week was still high for this time of year.

This was about 20 per cent more than the average number of cases reported for the same period in the preceding three years, it added.

“A rise in the high number of dengue cases this time of year could result in Singapore entering the following year with an atypically large number of dengue cases,” said the agency.

It noted that when year-end dengue numbers rose in 2019 and 2021, the Republic saw large outbreaks in the following years.

Dengue cases hit a record high of 35,315 cases in 2020, but went down to 5,258 in 2021.

The NEA has attributed the high number of cases in 2022 to the DenV-3 strain of dengue, which the population here has lower immunity against.

On Monday, it said that as at last Friday, it had closed about 97 per cent, or 2,959, of the 3,028 dengue clusters here that had emerged since the start of the year.

Some 69 dengue clusters still remain, the agency said.

“Clusters with a relatively fast rate of dengue transmission continued to surface – such as the 37-case cluster at Pasir Ris Street 71 and the 19-case cluster at Jurong East Avenue 1,” it said, adding that most mosquito breeding habitats in these areas were found inside homes. The two clusters are still active, according to NEA’s website.

Between January and November this year, the NEA conducted some 841,000 dengue inspections islandwide, including about 5,200 checks at construction sites.

About 21,300 breeding areas for the dengue-spreading Aedes mosquito were found during these checks, it said.

The NEA also issued fines to 3,500 households for mosquito breeding during that period.

In July 2020, heavier penalties were introduced for mosquito breeding in homes, with households facing a fine of up to $5,000 or a jail term of up to three months, or both, for third and subsequent offences. Since that time, the agency has detected multiple mosquito breeding habitats in 1,470 of residences inspected, and repeated mosquito breeding in about 1,890 households.

NEA also issued 119 stop-work orders to construction sites this year, and charged 61 contractors in court with poor housekeeping and mosquito breeding.

Sixteen contractors received repeated stop-work orders.

The NEA urged those planning to travel during the year-end holidays to mosquito-proof their homes, such as by covering all toilet bowls in their homes, sealing off overflow pipes of flushing cisterns, and adding BTI insecticide – Bacillus thuringiensis israelensis, a bacterial toxin that kills mosquito larvae – to places where mosquitoes could potentially breed.