COLOMBO, June 29 (Xinhua) -- Sri Lanka's reported dengue cases have exceeded 52,000 this year, with 31 deaths recorded by midnight on Saturday, as health authorities warn that a change in the dominant virus strain and continued mosquito breeding are driving infections.
The rise in cases has also been linked to the return of Dengue Virus Serotype 2, or DENV-2, which now accounts for about 75 percent of confirmed infections. DENV-3, dominant in 2023, 2024 and 2025, now accounts for about 25 percent.
DENV-2 is not a new virus but a strain that had been controlled after the 2017 outbreak without being eliminated, said NDCU Director Kapila Kannangara. He said more people are now susceptible because immunity built up in recent years was largely against DENV-3.
Kannangara said the impact of the November 2025 cyclone remains a major factor, after floods, landslides and uncleared debris created breeding sites for mosquitoes.
He said intermittent rainfall since then has allowed breeding to continue outside Sri Lanka's usual dengue peaks linked to the South-West and North-East monsoons.
Poor waste disposal has also weakened control efforts, with discarded cups, cans, bottles and other containers continuing to collect rainwater, he said. ■
