Increase in dengue cases noted after resurgence of previously dominant dengue virus strain
A total of 261 dengue cases were reported last week, 20 per cent more than the previous week.
According to data from the National Environment Agency (NEA) website, there were 56 reported active dengue clusters as of Monday, of which 12 are coded red. This means they have 10 or more cases.
Two red zones with particularly fast rates of transmission are the 48-case cluster at Science Park Drive and the 34-case cluster at Lentor Loop.
Persistent dengue transmission has also been noted at the 66-case dengue cluster at Angklong Lane and other large clusters in Toa Payoh. There are 321 cases in total at Lorong 1 and Lorong 2 Toa Payoh, and 178 cases at Lorong 1A.
The Straits Times reported previously that there is a risk of a surge in dengue cases in the coming months as mosquitoes have been spreading a previously dominant virus strain, DenV-1, rapidly.
The NEA has seen an increase in DenV-1 cases over the past two months, replacing the DenV-3 serotype which drove Singapore’s dengue outbreak in 2022 and contributed mainly to cases in the first half of 2023.
In July, the proportion of DenV-1 cases was about 55 per cent, more than thrice the number of DenV-3 cases, which stood at 17 per cent.
“The rise in proportion of a previously less prevalent dengue virus serotype is of concern, as this has historically been associated with a surge in dengue cases months later,” the agency said.
Some 6,428 dengue cases have been reported in 2023 as of Sept 12. In 2022, a total of 32,325 cases were reported, the second highest number of cases in a year. The record high was 35,315 cases in 2020.