A total of 538 Grama Niladhari (GN) divisions across 14 districts in the country have been identified as high-risk areas for dengue transmission, according to the latest dengue control assessment for June 2026.

Health authorities have designated these areas for intensified dengue prevention and control activities due to the increased risk of disease transmission.

According to the report, the Western Province has been the most severely affected, with a majority of high-risk Grama Niladhari divisions identified in the Colombo, Gampaha, and Kalutara districts.

In the Colombo District, within the Colombo Municipal Council jurisdiction, Grama Niladhari divisions in several Medical Officer of Health (MOH) areas, including Maharagama, Piliyandala, Homagama, Kaduwela, Boralesgamuwa, Dehiwala, Egodauyana, and Gothatuwa, have been identified as high-risk zones.

Similarly, in the Gampaha District, Grama Niladhari divisions in several areas, including Attanagalla, Seeduwa, Kelaniya, Ragama, Minuwangoda, Negombo, Biyagama, Wattala, Katana, and Mahara, have been included in the high-risk list.

In the Kalutara District, Grama Niladhari divisions in the areas of Bandaragama, Horana, Ingiriya, Matugama, Panadura, Wadduwa, Kalutara, and Payagala have also been identified as high-risk areas.

Furthermore, the report notes that Grama Niladhari divisions in the Galle, Hambantota, Matara, Kandy, Matale, Ratnapura, Kegalle, Kurunegala, Puttalam, Badulla, and Batticaloa districts have also been included in the high-risk list.

See the full list below: