Minister for Health and Family Welfare K.G. Arunraj on Tuesday (September 8, 2026) said in the Assembly that the State government would undertake scientific studies to identify new ways to prevent the spread of dengue in Tamil Nadu. It will be conducted as three Cluster Randomised Controlled Studies in the Kadayanallur area of Tenkasi district, which has a high incidence of dengue.

Dr. Arunraj said the studies would examine whether additional protection against bites from Aedes mosquitoes, which transmit dengue, could be obtained through topical mosquito repellents applied to the body, natural mosquito repellents such as lemon eucalyptus oil, and vapourisers, and whether their use causes any side effects.

District Entomologist posts remain vacant in over 40 Health Unit Districts in T.N.

Although topical mosquito repellents can prevent mosquito bites when used individually, there have so far been no field studies or data to establish whether their use at the community level can reduce the spread of dengue, he said.

Dr. Arunraj said although successive governments in Tamil Nadu had taken various measures for dengue prevention, it continued to be a major public health concern. In 2025, a total of 25,580 people were affected by dengue and 12 deaths were reported. A total of 14,581 people have been affected and nine deaths have been reported so far this year.

Suspected dengue outbreak at Srilankan Tamils rehabilitation camp in Tenkasi

The studies will identify the most effective mosquito repellent, assess the combined benefit of mosquito nets and topical mosquito repellents, and assess additional household-level protection measures. Each study will have 48 clusters, with 20 households in each cluster. Thus, approximately 2,880 households will participate across the three studies, he said.

The studies, which will be undertaken at an estimated cost of ₹43 lakh, will also assess adherence to the interventions, their acceptability among the public, feasibility of implementation and cost.