13 dengue deaths in first half of 2024, more than double last year's total

SINGAPORE: A total of 13 people died from dengue in the first half of 2024, more than double the total for last year. 

Figures from the National Environment Agency's (NEA) latest dengue surveillance data, published on Wednesday (Jul 24), showed that six people died from April to June.

Seven deaths were reported in the first quarter of this year.

Singapore recorded six dengue deaths last year and 19 in 2022, when there was a dengue outbreak.

More than 10,100 cases have been reported so far this year, exceeding the total number recorded for the whole of 2023.

The threshold was crossed in the week of Jul 14 to Jul 20, when 236 cases were reported. Dengue cases tend to peak from May to October.

According to NEA's report, there were 4,090 dengue cases in the second quarter of this year, a 20.8 per cent decrease from the preceding three months.

Results of positive dengue samples tested between April and June showed that dengue virus serotype 2 (DENV-2) accounted for 52.2 per cent of the infections. 

It is followed by DENV-3, at 33.2 per cent.

In the last quarter, NEA identified 432 clusters, down 16 per cent from the first three months of this year.

Of the 432 clusters, 360 were closed in the same period.

NEA also detected about 4,800 mosquito breeding habitats in the second quarter, a 5 per cent decrease from the preceding three months. 

PROJECT WOLBACHIA  "NOT A SILVER BULLET"

There is currently a high population of Aedes mosquitoes in Singapore, said Associate Professor Christina Liew, a medical entomologist at NEA. 

One way the government is bringing down the population of Aedes mosquitoes is through Project Wolbachia. 

Under the project, male mosquitoes carrying the Wolbachia bacteria are released to mate with female mosquitoes and their resultant eggs do not hatch. 

But this is not a "silver bullet" nor an emergency control tool in dengue clusters, said Assoc Prof Liew.

As of Jul 24, there were 70 dengue clusters, with 12 clusters having 10 or more cases.

The largest in Jurong West has 107 cases, while the second at Benoi Road has recorded 49 cases.

When asked if there are plans to expand the project, which currently covers 35 per cent of households in Singapore, Assoc Prof Liew told CNA that Project Wolbachia is a "steady state programme" and that robust research needs to be done.

“We’ve always said that Wolbachia is a complementary tool,” she said. “It’s not something that you will deploy in an emergency outbreak area.”

The project has seen promising results, she added.

NEA said earlier this year that since the start of Project Wolbachia in 2016, it has observed “positive results” across study sites. 

There has been a more than 90 per cent reduction of the Aedes aegypti population in Bukit Batok, Choa Chu Kang, Tampines and Yishun. 

Data from 2019 to 2022 also indicated that residents living in areas with at least one year of releases are up to 77 per cent less likely to be infected with dengue.

“The project is really good and it really does work,” said Assoc Prof Liew.

COMMUNITY PLAYS A KEY ROLE 

The community plays an important role in decreasing the mosquito population, said Assoc Prof Liew.  

Most of the breeding for Aedes mosquitoes happens in homes, she said. 

“That is why the most important thing is really to get everyone to do their part to get rid of stagnant water in their homes.” 

According to NEA’s quarterly report, pails, flower pots and vases were among the top mosquito breeding habitats in homes from April to June. 

Additional reporting by Rachel Lim.