Dengue cases have fallen to their lowest level this year after the largest outbreak in Singapore history.
228 cases were reported last week, about seven times lower than the July high of 1,792 cases.
Last week’s number, released yesterday by the National Environmental Agency (NEA), also marks the fourth week in a row that cases have dropped below 300.
The death toll from dengue fever hit a record high of 29 that year. Possible causes for the historic outbreak were the dominance of an unusual load and more people being bitten by mosquitoes during the Covid-19 breaker at home.
The cumulative number of dengue cases this year – as of Thursday – is 34,844, exceeding the high of 22,170 cases in 2013.
However, as of August, cases have steadily declined due to community efforts to control infections, said Chew Ming Fai, vice chairman of the board and director general of public health at NEA.
This included frequent reviews by local residents for potential mosquito habitats and inspections by city councils.
Historical dengue outbreak
This year’s historic dengue outbreak was due to a number of factors, some related to Covid-19, the agency added. It started with high weekly infections between 300 and 400 and the dominance of the DenV-3 serotype, an unusual strain of the virus, in the first four months of this year.
Cases increased in May shortly after the circuit breaker started and peaked in July before steadily declining. 57 dengue clusters were reported on Thursday, seven fewer than the previous week. The agency has closed around 98 percent of the dengue clusters since the beginning of the year.
The NEA warned against complacency, however, as the weekly number of cases remains relatively high for this time of year. Although below the previous year’s figure, it is three times the average number of cases reported from 2016 to 2018.
The agency attributed this to the 20 percent increase in the adult Aedes aegypti mosquito population last month, as well as the relatively higher proportion of DenV-3 and DenV-4 serotype cases, which are less common in Singapore.
As of Thursday, more than 230 residential areas have high Aedes aegypti populations with large dengue clusters at 11 Tampines Street, Geylang Road, 21 Bukit Batok Street and Admiralty Drive.
The NEA said it will continue to conduct inspections with its partners to remove habitats for the mosquito breeding. It will also focus on areas with high Aedes aegypti populations, as well as construction sites and industrial spaces that are near residential areas.
Mosquito proof your home before stays
With stagnant water more likely to build up in unused premises, the agency added that the public should take precautions to prevent mosquitoes from spreading before they stop.
This includes preventing flower pots, plates and trays from collecting water and covering toilet bowls and floor traps. More information is available on the NEA website.
“Residents, especially those living in dengue cluster areas, should do their part and do the three dengue fever protections – spray insecticide in dark corners around the house, regularly apply insect repellent, and wear long-sleeved tops and long pants . ” added the agency.