Dengue cases in Tamil Nadu have declined for the third consecutive year, according to data from the State Health and Family Welfare Department. The State recorded 17,049 cases up to September 19, 2026, compared with 25,585 cases in 2025, 46,971 in 2024, and 56,863 in 2023.

The number of reported dengue cases fell by 17% between 2023 and 2024, followed by a 46% decline in 2025. The 2026 figure, however, covers only the period up to September 19 and cannot be compared with the full-year figures of previous years.

The data indicate a sustained decline in reported dengue cases, although the figures for 2026 could change over the remaining months.

The State reported nine dengue-related deaths up to September 19, 2026, as compared with 12 in 2025, 13 in 2024 and 12 in 2023.

Dengue is a mosquito-borne viral infection that can cause high fever, body pain and, in some cases, severe disease. Warning signs such as persistent abdominal pain, repeated vomiting, bleeding and extreme weakness require prompt medical attention.

The year-on-year decline in reported cases and deaths provides an overview of the State’s dengue burden, but the data do not establish the reasons for the decline.

Continued surveillance and measures to control the Aedes mosquito, which transmits dengue, remain important for prevention.