The weekly dengue instances fall to their lowest degree within the “historic outbreak 12 months”. The NEA urges continued vigilance
SINGAPORE: Singapore’s weekly dengue numbers have fallen to their lowest levels this year. In the week of December 12th, 228 cases were reported, the National Environment Agency (NEA) announced on Friday (December 18).
This is seven times lower than the high of 1,792 cases in July and the fourth straight week that case numbers have stayed below 300.
However, the weekly numbers between 200 and 300 for this time of year are still “relatively high,” NEA said when it called for continued vigilance with mosquito breeding site eradication.
Number of dengue cases from 2016 to 2020 (as of epidemiological week 50). (Source: National Environment Agency)
The number of dengue cases in Singapore hit a record high in August, surpassing the high of 22,170 cases in 2013.
As of Thursday this year, 34,844 dengue cases had been reported.
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Describing 2020 as a “historic dengue outbreak year”, NEA said it was caused by a “confluence of factors” including the effects of the COVID-19 pandemic and the presence of the less common DENV-3 dengue virus serotype for whom the community has low immunity.
Weekly cases rose sharply in May just after the “breaker” period and finally peaked in July, NEA noted.
Work-from-home agreements increased the likelihood of contact with the Aedes aegypti mosquitoes, while the cessation of work on construction sites from April to June resulted in mosquito breeding in those locations tripling compared to January to March, NEA said.
The agency added that more mosquito breeding was found in private households as well, suggesting that this “may be due to the challenges residents face with home juggling, the higher household burden and home schooling of children” .
“A concerted effort by all parties has helped bring this year’s dengue outbreak under control,” said NEA.
A worker sprays insect repellent as a preventive measure against the spread of dengue fever in a neighborhood garden in Singapore on Aug. 25, 2020. (File Photo: AFP / Roslan Rahman)
Continuation of vigilance required
While the weekly numbers have decreased and are lower compared to the same period last year, NEA pointed out that the number of cases is still around three times the average number reported during that time of year between 2016 and 2018.
“Two other indicators that need to be observed are the 20 percent increase in the adult Aedes aegypti mosquito population in November – there are currently over 230 residential areas with a high Aedes aegypti mosquito population – and the relatively higher proportion of DENV-3 and DENV -4 serotype cases that are less common in Singapore, “the agency said.
“We therefore urge everyone to remain vigilant against the dengue threat and to maintain the good efforts made to curb dengue transmission.”
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NEA closed 98 percent of the dengue clusters reported this year, or 3,003 out of 3,060, despite warnings that large clusters remain on Admiralty Drive, 21 Bukit Batok Street, Geylang Road, and 11 Tampines Street.
Between January and November, NEA conducted around 954,000 mosquito breeding inspections across Singapore, including 6,900 inspections at construction sites.
The inspections revealed approximately 21,500 mosquito breeding habitats and 7,060 enforcement actions were taken against owners of premises where mosquitoes breed.
PRECAUTIONS FOR THE STAY
The NEA also urged those who were staying to protect their homes against mosquitoes.
This can be achieved by covering toilet bowls, floor traps and overflow pipes from cisterns, adding insecticides containing Bacillus thuringiensis israelensis (Bti) to potential breeding grounds, and removing debris and blockages from gutters and drains.
Homeowners should also flip all water storage containers over and wipe the edges dry, making sure flower pots, plates and trays do not collect water.
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“The dengue risk is real as the virus is endemic to Singapore, the historic dengue outbreak this year, and a significant proportion of residents are still working from home,” the agency said.
“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 . “